Impairment of Sexual Function in Rats with Epilepsy

IntroductionEpilepsy is a chronic disease that affects men and women of all ages, with different levels of severity. Many individuals with epilepsy also suffer from impairments in sexual function. However, it is difficult to differentiate between the impact of the disease and the impact of antiepileptic drugs on sexual function in human subjects.AimsTo evaluate sexual behavior in adult male rats submitted to chronic pilocarpine‐induced epilepsy.MethodsFirst, non‐epileptic rats were exposed to nine training sessions to acquire sexual experience, and their baseline sexual performance was evaluated. Then, the same rats were given pilocarpine to induce status epilepticus followed by chronic epilepsy. Once the animals had developed spontaneous recurrent seizures, their sexual behavior was evaluated during three sessions.Main Outcome MeasuresExamine changes in latencies to first mount, intromission, and ejaculation, and the total number of mounts, intromissions, and ejaculations.ResultsAll outcome measures related to sexual motivation and sexual performance were markedly impaired during chronic epilepsy compared with the baseline and the control group.ConclusionThese findings will aid in understanding the interaction between sexual behavior and epilepsy, as well as encouraging further experimental studies in human patients with epilepsy suffering from sexual dysfunction. Andersen ML, Alvarenga TA, Scorza FA, Matos G, Sonoda EY, Hirotsu C, Cavalheiro EA, and Tufik S. Impairment of sexual function in rats with epilepsy. J Sex Med 2012;9:2266–2272.     

Estrogens in Men: Clinical Implications for Sexual Function and the Treatment of Testosterone Deficiency

IntroductionThe role of estrogens in male sexual function and the pathogenesis of testosterone deficiency remain controversial and poorly understood.AimsTo review the distribution of estrogens in normal and testosterone deficient men, their potential role in sexual function, and the clinical implications of elevated estrogens during testosterone therapy.MethodsA comprehensive, broad-based literature review was conducted on the role of estrogens in male sexual function and testosterone deficiency.ResultsEstrogens elicit a variety of physiological responses in men and may contribute to modulation of sexual function. In the absence of testosterone deficiency, elevations in estrogens do not appear to be harmful and estrogens may help maintain some, but not all, sexual function in castrated men. While the therapeutic use of estrogens at pharmacologic doses has been used to suppress serum testosterone, naturally occurring elevations of estrogens do not appear to be a cause of low testosterone. During testosterone replacement, estrogens may rise and occasionally reach elevated levels. There is a lack of evidence that treatment of elevated estrogen levels during testosterone replacement has benefit in terms of male sexuality.ConclusionsFurther research on the importance of estrogens in male sexual function is needed. Current evidence does not support a role of naturally occurring estrogen elevations in testosterone deficiency or the treatment of elevated estrogens during testosterone therapy. Kacker R, Traish AM, and Morgentaler A. Estrogens in men: Clinical implications for sexual function and the treatment of testosterone deficiency. J Sex Med 2012;9:1681–1696.     

Combination of testosterone and vardenafil increases female sexual functioning in sub-primed rats

IntroductionHypoactive sexual desire disorder (HSDD) is a common problem in women and may have a negative impact on quality of life. A recent clinical study shows an increase in sexual drive of HSDD women after cotreatment of testosterone and vardenafil (phosphodiesterase type 5 inhibitor).AimIn this study, we investigated the effect of testosterone and vardenafil on sexual activity in female rats.Main Outcome MeasuresProceptive (darts and hops), receptive (lordosis), and paced‐mating (percentages after exits and contact‐return latencies) behaviors were quantified.MethodsOvariectomized female rats, sub‐primed with only estradiol and fully primed with estradiol and progesterone, were tested in a paced‐mating sex test and sexual behaviors were quantified. The sub‐primed rats are thought to model HSDD. The effect of testosterone (100 and 300 µg, subcutaneous [SC]) and vardenafil (10 mg/kg, per os [PO]) alone and testosterone (300 µg, SC) in combination with vardenafil (3 and 10 mg/kg, PO) were tested. We also studied the effects of testosterone (300 µg, SC) + intracerebroventricular (ICV) injections of vardenafil (25 and 50 µg) on sexual activity.ResultsNo effect of testosterone and vardenafil alone was found, but cotreatment of testosterone and vardenafil (PO) caused a significant increase in proceptive and receptive behavior in the sub‐primed female rats. Testosterone and vardenafil did not affect fully primed females. ICV administration of vardenafil combined with systemic testosterone, on the other hand, had no effect on sexual activity in both sub‐primed and fully primed female rats.ConclusionsWe conclude that cotreatment of subcutaneous testosterone and oral vardenafil increase sexual activity in sub‐primed female rats. Our data supports the human finding that combination treatment of testosterone and vardenafil could be used as a new treatment for women with HSDD. Snoeren EMS, Bovens A, Refsgaard LK, Westphal KGC, Waldinger MD, Olivier B, and Oosting RS. Combination of testosterone and vardenafil increases female sexual functioning in sub‐primed rats.     

Anandamide Transforms Noncopulating Rats into Sexually Active Animals

IntroductionNoncopulating (NC) male rats are apparently normal and healthy animals that will not mate despite repeated exposure to sexually receptive females. Several lines of evidence suggest the involvement of endogenous opioids in this sexual inhibitory state. Endogenous opioids and endocannabinoids are neuromodulators of neurotransmitter release, although through different mechanisms.AimTo establish if the endocannabinoid anandamide was able to induce sexual behavior expression in male rats classified as noncopulators.MethodsNC male rats were intraperitoneally (i.p.) injected with anandamide or vehicle and tested for copulatory behavior with a receptive female during 120 minutes. Fourteen days after anandamide or vehicle injection, the animals were subjected to a second sexual behavior test during 60 minutes.Main Outcome MeasuresThe percentage of rats showing male sexual behavior responses: mount, intromission, ejaculation, and copulation resumption after ejaculation and the specific sexual behavior parameters were quantified.ResultsAnandamide injection induced sexual behavior expression in 50% of previously NC rats, while the NC animals injected with vehicle did not show sexual behavior. The responding animals executed several successive ejaculatory series and were still capable of showing sexual behavior 14 days after anandamide injection. Copulation in these rats (the first copulatory series) was characterized by a large number of mounts and intromissions preceding ejaculation, as well as by statistically significant increases in the latencies to mount, intromit, and ejaculate when compared with the sexual performance of sexually naïve animals copulating for the first time.ConclusionThe endocannabinoid anandamide transforms previously NC rats into sexually active animals, capable of showing sexual behavior in a long-lasting manner. Only half of the NC population responds to anandamide injection, suggesting that different mechanisms underlie the sexual inhibition of NC rats. The endocannabinoid system seems to play a role in the regulation of male rat sexual behavior expression. Canseco-Alba A and Rodríguez-Manzo G. Anandamide transforms noncopulating rats into sexually active animals. J Sex Med 2013;10:686–693.     

The Serotonin Transporter Plays an Important Role in Male Sexual Behavior: A Study in Serotonin Transporter Knockout Rats

IntroductionSerotonin (5‐HT) is an important neurotransmitter for sexual behaviors. Heterozygous (+/?) serotonin transporter (SERT) rats and SERT knockout rats (?/?) have serotonergic disturbances with significant elevations of basal extracellular 5‐HT levels.AimTo investigate the putative role of the SERT in male sexual behavior.MethodsAfter extensive sexual training, the effects of the 5‐HT_1A/7 receptor agonist ±8‐OH‐DPAT, the 5‐HT_1A receptor antagonist WAY100 635 and a combination of both on sexual behaviors of SERT^?/? and SERT^+/? knockout and wildtype (SERT^+/+) male Wistar rats were examined.Main Outcome MeasuresMale rat sexual behaviors of mounts, intromissions, and ejaculations.ResultsSERT^?/? had lower basal ejaculation frequencies than SERT^+/? and SERT^+/+ animals. ±8‐OH‐DPAT enhanced sexual performance in all three genotypes to the same extent. WAY100635 dose‐dependently inhibited sexual behavior in all three genotypes with significant dose to genotype interactions. WAY100635 exerted the strongest effects in SERT^?/? animals. The combination of a dose range of ±8‐OH‐DPAT and a selected dose of WAY100635 revealed only partial antagonism by ±8‐OH‐DPAT of the sexual inhibitory effects of WAY100635.Conclusions.Absence of the serotonin transporter reduces basal ejaculatory performance in male rats. Pharmacological experiments suggest that separate pools of 5‐HT_1A receptors regulate different aspects of sexual performance in male rats. 5‐HT₇ receptors may play a minor role in the partial recovery of sexual behavior after combination of ±8‐OH‐DPAT and WAY100635. The SERT^?/? rat may be a model for chronic SSRI treatment, delayed ejaculation, anorgasmia, and/or low libido. Chan JSW, Snoeren EMS, Cuppen E, Waldinger MD, Olivier B, and Oosting RS. The serotonin transporter plays an important role in male sexual behavior: A study in serotonin transporter knockout rats.     

BP101 Peptide Promotes Female Sexual Receptivity in the Rat

IntroductionLow sexual desire is a frequent sexual problem in women, with only one drug for the condition approved by the Food and Drug Administration.AimTo evaluate the ability of a novel synthetic peptide, BP101, to facilitate sexual behavior after intranasal administration or infusion into certain brain areas in female rats.MethodsBilaterally ovariectomized female rats, primed with a suboptimal combination of estradiol benzoate (EB) and progesterone, were used as a model of low sexual motivation. Sexual behavior was tested with stud male rats after acute (experiment 1) or long-term (experiment 2) intranasal administration of BP101 or peptide infusion into the olfactory bulb, medial preoptic area, ventromedial hypothalamic nucleus, or ventral tegmental area (experiment 3).Main Outcome MeasuresFrequency of solicitations (SF), as an indicator of sexual motivation in female rats, and lordosis frequency and ratio, as measurements of female consummatory sexual behavior.ResultsAcute intranasal BP101 administration moderately increased SF, with the highest tested dose of 300 μg/kg causing an 80% increase. Female rats receiving BP101 75 or 300 μg/kg daily on days 6 to 16 of the peptide administration displayed twofold higher SF compared with the placebo-treated animals, an increase comparable to optimally hormone-primed female rats. Infusion of BP101 1 and 5 μg per rat into the medial preoptic area, but not into the olfactory bulb, ventromedial hypothalamic nucleus, or ventral tegmental area, increased SF in female rats supplemented with EB 10 or 20 μg. The effect was relatively more pronounced in female rats receiving EB 10 μg (≈300%) compared with EB 20 μg (≈50%) with direct brain infusions.ConclusionBP101 displays a potent stimulatory effect on sexual motivation in the female rat, and the medial preoptic area seems to be the site of its action. BP101 is effective in female rats receiving different hormone supplementations, making the present data generalizable to pre- and postmenopausal women with hypoactive sexual desire.Andreev-Andrievskiy A, Lomonosov M, Popova A, et al. BP101 Peptide Promotes Female Sexual Receptivity in the Rat. J Sex Med 2017;14:336–346.     

Effect of Mucuna pruriens (Linn.) on Sexual Behavior and Sperm Parameters in Streptozotocin‐Induced Diabetic Male Rat

IntroductionSexual dysfunction is one of the major secondary complications in the diabetic. Mucuna pruriens, a leguminous plant identified for its antidiabetic, aphrodisiac, and improving fertility properties, has been the choice of Indian traditional medicine.AimObjective of the present study was to analyze the efficacy of M. pruriens on male sexual behavior and sperm parameters in long‐term hyperglycemic male rats.MethodsMale albino rats were divided as group I control, group II diabetes induced (streptozotocin [STZ] 60 mg/kg of body weight (b.w.) in 0.1 M citrate buffer), group III diabetic rats administered with 200 mg/kg b.w. of ethanolic extract of M. pruriens seed, group IV diabetic rats administered with 5 mg/kg b.w. of sildenafil citrate (SC), group V administered with 200 mg/kg b.w. of extract, and group VI administered with 5 mg/kg b.w. of SC. M. pruriens and SC were administered in single oral dosage per day for a period of 60 days. The animals were subjected to mating behavior analyses, libido, test of potency, and epididymal sperms were analyzed.Main Outcome MeasureThe mating behavior, libido, test of potency, along with epididymal sperms were studied.ResultsThe study showed significant reduction in sexual behavior and sperm parameters in group II. Daily sperm production (DSP) and levels of follicular stimulating hormone, luteinizing hormone, and testosterone were significantly reduced in group II, whereas the animals with diabetes administered with seed extract of M. pruriens (group III) showed significant improvement in sexual behavior, libido and potency, sperm parameters, DSP, and hormonal levels when compared to group II.ConclusionThe present work reveals the potential efficacy of ethanolic seed extract of M. pruriens to improve male sexual behavior with androgenic and antidiabetic effects in the STZ‐induced diabetic male rats. This study supports the usage of M. pruriens in the Indian system of medicine as sexual invigorator in diabetic condition and encourages performing similar study in men. Suresh S, and Prakash S. Effect of Mucuna pruriens (Linn.) on sexual behavior and sperm parameters in streptozotocin‐induced diabetic male rat. J Sex Med 2012;9:3066–3078.     

Endocrine Aspects of Male Sexual Dysfunctions

IntroductionEndocrine disorders may adversely affect men's sexual function.AimTo provide recommendations based on best evidence for diagnosis and treatment of endocrine-related male sexual dysfunctions.MethodsThe Endocrine Aspects of Male Sexual Dysfunctions Committee, including 11 members from eight countries and four continents, collaborated with the Endocrine subcommittee of the Standards Committee of the International Society for Sexual Medicine. Medical literature was reviewed in detail, followed by extensive internal committee discussion over 2 years, then public presentation and discussion with the other experts before finalizing the report.Main Outcome MeasureRecommendations based on grading of evidence-base medical literature and interactive discussion.ResultsFrom animal studies, it is derived that testosterone modulates mechanisms involved in erectile machinery, including expression of enzymes that both initiate and terminate erection. In addition, testosterone is essential for sexual motivation. Whether these findings could be extrapolated to human erections is unclear. Testosterone plays a broad role in men's overall health. Recent studies have established strong associations between low testosterone and metabolic and cardiovascular imbalances. In some studies, low testosterone decreased longevity; however, longitudinal studies do not support the predictive value of low testosterone for further cardiovascular events. The article proposes a standardized process for diagnosis and treatment of endocrine-related male sexual dysfunctions, updating the knowledge on testosterone and prostate safety. There is no compelling evidence that testosterone treatment causes prostate cancer or its progression in men without severe testosterone deficiency (TD). The possible roles of prolactin and thyroid hormones are also examined.ConclusionsMen with erectile dysfunction, hypoactive sexual desire and retarded ejaculation, as well as those with visceral obesity and metabolic diseases, should be screened for TD and treated. Prospective interventional studies are required before screening for TD in more conditions, including cardiovascular diseases, and considering correction as preventive medicine as much data suggests. Buvat J, Maggi M, Gooren L, Guay AT, Kaufman J, Morgentaler A, Schulman C, Tan HM, Torres LO, Yassin A, and Zitzmann M. Endocrine aspects of male sexual dysfunctions.     

Paradoxical Sleep Deprivation Influences Sexual Behavior in Female Rats

IntroductionSleep disturbances are a frequent complaint in women and are often attributed to hormonal fluctuations during the menstrual cycle. Rodents have been used as models to examine the effects of sleep deprivation on hormonal and behavioral changes. Among the many comorbidities common to sleep disorders, sexual behavior remains the least well studied.AimTo determine whether paradoxical sleep deprivation (PSD) can affect sexual receptivity (male acceptance) and proceptivity (male solicitation) behaviors in female rats.MethodsFemale Wistar rats were subjected to PSD or were maintained as controls. After this period, the estrous cycle (proestrus, estrus, and diestrus) was determined, and all females were placed with a sexually experienced male. In order to investigate the role of hormones in sexual behavior, we included additional groups that were artificially induced to be sexually receptive via administration of a combination of estradiol and progesterone.Main Outcome MeasurementsReceptivity and proceptivity behaviors, as well as progesterone and corticosterone concentrations were monitored.ResultsSelective sleep loss caused a significant increase in proceptivity and receptivity behaviors in females exclusively during the proestrus phase. The rejection response was increased in PSD rats during the estrus and diestrus phases, as compared with PSD-receptive and proestrus females. PSD reduced progesterone levels during the proestrus phase relative to the respective control group during the same phase of the estrous cycle. The PSD-proestrus females that displayed the most robust sexual response exhibited greater concentrations of corticosterone than PSD-diestrus females, with an absence of sexual solicitation behaviors.ConclusionsPSD produced a distinct response in the hormonal profile that was consistent with the phase of the estrous cycle. These results show that sleep loss can affect sexual motivation and might lead to important clinical implications, including alterations in female physiology and reproductive abnormalities. Andersen ML, Alvarenga TAF, Guindalini C, Perry JC, Silva A, Zager A, and Tufik S. Paradoxical sleep deprivation influences sexual behavior in female rats. J Sex Med 2009;6:2162–2172.     

The Relevance of Sexual Responsiveness to Sexual Function in Male Stroke Patients

IntroductionStroke may have negative consequences for the patients' quality of life, including sexual function. Whereas physical impairment will influence sexual positions and movement during sex, depression and medication may reduce sexual desire. So far, data on sexual dysfunction after stroke are scant. Although some support for physical as well as psychological explanations has been shown, further research to find the remedies for those patients with sexual problems after stroke is needed. The focus of the present study is on the identification of relevant psychological factors.AimThe aim of this study was to study the impact of anxiety, depression, and sexual responsiveness on sexual function in male stroke patients.MethodsNineteen male stroke patients completed a number of self‐report measures to assess psychological and sexual factors.Main Outcome MeasuresSexual function based on the International Index of Erectile Function, anxiety and depression based on the Symptom Checklist‐90, and sexual responsiveness based on the Sexual Inhibition/Sexual Excitation Scale, including propensities for sexual excitation and sexual inhibition as a result of both performance failure and performance consequences, were assessed.ResultsSexual excitation was positively related to sexual desire, whereas inhibition because of the threat of performance failure was negatively related to orgasmic function and sexual desire (P < 0.01). Patients with high levels of inhibition because of threat of performance failure were more likely to report low scores on overall sexual function than those with low levels.Conclusions.Although the statistical power is rather low, the results show the relevance of sexual responsiveness to sexual function in male stroke patients. The present study can be considered as a first step toward building a theoretical framework of relevant psychological and physical factors, which is needed to develop adequate interventions for those patients with sexual problems after stroke. Duits A, van Oirschot N, van Oostenbrugge RJ, and van Lankveld J. The relevance of sexual responsiveness to sexual function in male stroke patients.     

ORIGINAL RESEARCH—ENDOCRINOLOGY: Hypogonadism,Decreased Sexual Desire,and Long-Term Depression in Middle-Aged Men

IntroductionIn middle-aged men, the associations between long-term depressive symptoms and circulating testosterone levels are poorly known, although it is known that testosterone levels decrease with age.MethodsA health questionnaire was mailed to a population-based sample from the National Population Register in 1998, 1999, and 2001. Based on their self-reported mental symptoms, a total of 116 men were selected for clinical examination in 2005. Half of them had high and the others low levels of adverse mental symptoms in all three previous follow-ups. A structured clinical interview for Diagnostic and Statistical Manual of Mental Disorders-IV was performed. Depressive symptoms were assessed with the Beck Depression Inventory (BDI) and the Hamilton Depression Rating Scale (HDRS). The Aging Males’ Symptoms scale was also compiled and testosterone levels were determined.ResultsIn the entire study sample, serum free testosterone levels correlated negatively with both BDI and HDRS scores. In the hypogonadism group (based on free testosterone, 19.8% of the sample), clinically significant depression (BDI score ≥ 13) was more than three times as frequent as in the other men (34.8% vs. 10.4%), the odds ratio after multiple adjustments being 4.98 (95% confidence interval 1.66–14.95). A decrease in sexual desire was common in hypogonadism (36%). Nevertheless, it also associated with clinically significant depression, irrespective of free testosterone levels.DiscussionLong-term and current depressive symptoms, a decreased sexual desire, and low serum free testosterone levels are associated in middle-aged men. Hypogonadism per se and as a cause of decreased sexual desire may be a contributory and possibly treatable factor underlying male depression.ConclusionsThe findings highlight the need for hormonal status assessment in middle-aged depressive men. Hintikka J, Niskanen L, Koivumaa-Honkanen H, Tolmunen T, Honkalampi K, Lehto SM, and Viinamäki H. Hypogonadism, decreased sexual desire, and long-term depression in middle-aged men. J Sex Med 2009;6:2049–2057.     

Improvement of sexual function in men with late-onset hypogonadism treated with testosterone only

AimLate-onset hypogonadism is associated with relatively mild testosterone deficiencies. This study investigated the effects of restoring testosterone levels to normal in men with complaints of low sexual desire and erectile dysfunction.Main Outcome MeasuresSexual function was assessed with the International Index of Erectile Function (IIEF) at baseline and after 24 weeks of testosterone administration.MethodsTwenty-two hypogonadal men (mean age 58 years) with erectile dysfunction were studied. Fifteen patients had serum testosterone below 6.9 nmol/L, and seven between 7.2 and 11.7 nmol/L (reference values in our laboratory ≥12.0 nmol/L); there were considerable comorbidities. The duration of sexual complaints was on average 3.8 years. Patients received intramuscular long-acting testosterone undecanoate.ResultsIn all patients, serum testosterone levels were restored to normal within 6–8 weeks. Twelve patients reported a significant improvement in the sexual desire domain (from 4.5 to 8.4) and experienced an improvement in the erectile function domain (from 12 to 25 [Questions 1–5 plus 15)], following treatment with this long-acting testosterone; in 9 of 12 patients, this occurred only after at least 12–24 weeks. The remaining 10 patients reported an improvement of sexual desire (from 4.5 to 7.5), but no significant improvement in the erectile function domain (from 12 to 14). No changes in serum prostate-specific antigen or prostate volume were noticed while receiving this long-acting testosterone preparation.ConclusionRestoring testosterone levels to normal in men with proven subnormal testosterone levels improves libido in most subjects, and erectile function in more than 50% of these men. It may take 12–24 weeks before the effects of testosterone become manifest. Yassin AA, and Saad F. Improvement of sexual function in men with late-onset hypogonadism treated with testosterone only.     

Effect of Cinnamomum cassia Methanol Extract and Sildenafil on Arginase and Sexual Function of Young Male Wistar Rats

IntroductionHerbs have been used as an aphrodisiac since ages. Cinnamomum cassia is an important ingredient of many Ayurvedic formulations to treat male sexual disorder including erectile dysfunction (ED).AimThe objective of the present study was to evaluate erectogenic and aphrodisiac activity of methanol extract of C. cassia bark in young male rats.MethodsMethanol extract of C. cassia was screened in vitro for arginase inhibition potential and IC₅₀ was determined. Effect of the extract was observed in vitro on phenylephrine pre-contracted isolated rat corpus cavernosum smooth muscle (CCSM) at 0.1, 1, 10, and 100 μg/mL. Young male Wistar rats were dosed with extract at 100 mg/kg body weight for 28 days and its effects on sexual behavior and penile smooth muscle : collagen level were observed.Main Outcome MeasureEffect of C. cassia was studied on arginase activity in vitro and sexual behavior of young male rats.ResultsC. cassia inhibited arginase activity in vitro with an IC₅₀ of 61.72 ± 2.20 μg/mL. The extract relaxed phenylephrine pre-contracted isolated rat CCSM up to 43% and significantly increased (P < 0.05) sexual function of young male rats. Treatment with the extract also increased smooth muscle level and decreased collagen level in rat penile tissue.ConclusionThe study proves usefulness of methanol extract of C. cassia bark for increasing sexual function. Goswami SK, Inamdar MN, Jamwal R, and Dethe S. Effect of Cinnamomum cassia methanol extract and sildenafil on arginase and sexual function of young male Wistar rats. J Sex Med 2014;11:1475–1483.     

Formaldehyde Inhibits Sexual Behavior and Expression of Steroidogenic Enzymes in the Testes of Mice

BackgroundFormaldehyde, a ubiquitous environmental pollutant, is used extensively and has been proved to impair male reproduction in mammals. However, no trials have explored whether formaldehyde affects sexual function.AimTo evaluate the effect of long-term formaldehyde exposure on sexual behavior and to investigate the potential mechanism.MethodsForty C57BL/6 male mice were randomly allocated to four equally sized groups. Mice were exposed to formaldehyde at a dose of 0 (control), 0.5, 5.0, or 10.0 mg/m³ by inhalation for 60 days.OutcomesSexual behavior, body and reproductive organ weights, testosterone concentration in serum and testicular tissue, expression of steroidogenic enzymes, quality of sperm, and testicular structure were measured.ResultsFormaldehyde inhibited sexual behavior and decreased reproductive organ weights in mice. Serum testosterone levels and intratesticular testosterone concentrations were decreased in the formaldehyde-treated groups. Expression levels of steroidogenic enzymes, including steroidogenic acute regulatory protein, cytochrome P450 cholesterol side-chain cleavage enzyme, and 3β-hydroxysteroid dehydrogenase (3β-HSD), also were decreased in the testes of mice exposed to formaldehyde. Moreover, the structure of seminiferous tubules was destroyed and sperm quality decreased after formaldehyde exposure. In addition, the results indicated that the effects of formaldehyde were dose dependent.Clinical ImplicationsEfforts should be undertaken to decrease impairment of sexual function caused by formaldehyde exposure.Strengths and LimitationsThe relatively small sample might have affected the outcomes. Further experiments are needed to study the mechanism of action of formaldehyde.ConclusionExposure to formaldehyde gas inhibited sexual behavior, caused reproductive organ atrophy, and impaired spermatogenesis in male mice, which might have been induced by suppressed expression of steroidogenic enzymes in Leydig cells and decreased testosterone synthesis.Zang Z-J, Fang Y-Q, Ji S-Y, et al. Formaldehyde Inhibits Sexual Behavior and Expression of Steroidogenic Enzymes in the Testes of Mice. J Sex Med 2017;14:1297–1306.     

Acute and chronic dosing of Lepidium meyenii (Maca) on male rat sexual behavior

IntroductionThe use of natural remedies for the treatment of sexual disorders is under current investigation. For generations people of the rural community in Peru have used Lepidium meyenii Walpers (Maca), because of their belief that it improves fertility and sexual desire.AimTo determine the acute and chronic effects of Maca on male sexual behavior and to examine chronic administration of Maca on anxiety.Main Outcome MeasuresEjaculatory and mounting behavior and postejaculatory interval. Anxiety tests using an elevated plus maze, locomotion, and social interaction with another male.MethodsMaca (25 and 100 mg/kg) was orally administered to male rats for 30 days. Male sexual behavior was monitored after acute, 7 and 21 days of treatment. Anxiety behavior and locomotion were measured at 28–29 days using the elevated plus maze and social interaction tests.ResultsMaca treatment did not produce large changes in male sexual behavior. However, an increase in ejaculation latency and postejaculatory interval was observed after both acute and 7 days of treatment. After 21 days of treatment Maca had no effect on sexual behavior. Chronic administration of Maca did not increase locomotion or anxiety.ConclusionAcute and short-term administration of Maca produced a small effect of rat male sexual behavior and long-term administration did not increase anxiety. Lentz A, Gravitt K, Carson CC, and Marson L. Acute and chronic dosing of Lepidium meyenii (Maca) on male rat sexual behavior.     

Association of risk factors and medical comorbidities with male sexual dysfunctions

IntroductionConventionally, little attention has been given to the association of risk factors and medical comorbidities with male sexual dysfunctions. Although that association has been recently shown in many studies, it is not yet well investigated in the Saudi community.AimTo investigate the association of risk factors and medical comorbidities with male sexual dysfunctions in the Saudi community.MethodsA total of 1,464 male patients with a clinical diagnosis of sexual dysfunctions were enrolled in this study. All patients were assessed for sexual functions using different domains of the International Index for Erectile Function. Patients were also interviewed for sociodemographic data, medical history, and risk factors for erectile dysfunction (ED). Routine laboratory investigations, plus total testosterone and prolactin assessments, were offered to all patients. Assessments of penile vasculature using Doppler ultrasonography and rigidometer were performed.ResultsA total of 92.6% of the patients had ED, 50.8% had premature ejaculation (PE), and 7.6% had low sexual desire. There was a significant association between increased age and increased severity of ED. In total, 20% had psychogenic cause, whereas 80% had organic cause of ED. Of the patients, 10.2% had mild, 41% had moderate, and 48.8% had severe ED. There were significant associations between endocrinopathy and both low sexual desire and PE (P < 0.05). There were significant associations between increased severity of ED and presence of diabetes, hypertension, dyslipidemia, ischemic heart disease, myocardial infarction, and psychological disorders. There were significant associations between increased severity of ED and increased values of end diastolic velocity, decreased values of peak systolic velocity, resistive index, rigidometer, and decreased response to intracavernosal injection (P < 0.001).ConclusionThis study provides an assessment of the association of risk factors and medical comorbidities with male sexual dysfunctions in ambulatory service in this community. El-Sakka AI. Association of risk factors and medical comorbidities with male sexual dysfunctions.     

Androgens and Psychosocial Factors Related to Sexual Dysfunctions in Premenopausal Women1: 12016 ISSM Female Sexual Dysfunction Prize

IntroductionThe female sexual response is complex and influenced by several biological, psychological, and social factors. Testosterone is believed to modulate a woman's sexual response and desire, because low levels are considered a risk factor for impaired sexual function, but previous studies have been inconclusive.AimTo investigate how androgen levels and psychosocial factors are associated with female sexual dysfunction (FSD), including hypoactive sexual desire disorder (HSDD).MethodsThe cross-sectional study included 428 premenopausal women 19 to 58 years old who completed a questionnaire on psychosocial factors and had blood sampled at days 6 to 10 in their menstrual cycle. Logistic regression models were built to test the association among hormone levels, psychosocial factors, and sexual end points.Main Outcome MeasuresFive different sexual end points were measured using the Female Sexual Function Index and the Female Sexual Distress Scale: impaired sexual function, sexual distress, FSD, low sexual desire, and HSDD. Serum levels of total and free testosterone, androstenedione, dehydroepiandrosterone sulfate, and androsterone glucuronide were analyzed using mass spectrometry.ResultsAfter adjusting for psychosocial factors, women with low sexual desire had significantly lower mean levels of free testosterone and androstenedione compared with women without low sexual desire. None of the androgens were associated with FSD in general or with HSDD in particular. Relationship duration longer than 2 years and mild depressive symptoms increased the risk of having all the sexual end points, including FSD in general and HSDD in particular in multivariate analyses.ConclusionIn this large cross-sectional study, low sexual desire was significantly associated with levels of free testosterone and androstenedione, but FSD in general and HSDD in particular were not associated with androgen levels. Length of relationship and depression were associated with FSD including HSDD.Wåhlin-Jacobsen S, Kristensen E, Tønnes Pedersen A, et al. Androgens and Psychosocial Factors Related to Sexual Dysfunctions in Premenopausal Women. J Sex Med 2017;14:366–379.     

Independent Association of Erectile Dysfunction and Low Testosterone Levels With Life Dissatisfaction in Men With Chronic Spinal Cord Injury

BackgroundThe loss of global functional independence, along with bladder, bowel, and sexual dysfunctions, may contribute to psychological distress and life dissatisfaction after spinal cord injury (SCI).AimTo explore the relationship of erectile function and androgenic status with life satisfaction, independently from confounders recognizable in spinal cord–injured men.Methods100 consecutive men (49 ± 17 years) admitted to a rehabilitation program because of chronic SCI (≥1 year) underwent clinical/biochemical evaluations, including the assessment of life and sexual satisfaction using the Life-Satisfaction Questionnaire-9 (LiSat-9), erectile function using the International Index of Erectile Function-5 (IIEF-5), global and bowel-bladder functional independence using the Spinal Cord Independence Measure (SCIM) and measurement of total testosterone (TT) levels. The free testosterone level was calculated using the Vermeulen formula.OutcomesThe outcomes include the relationship between sexual health and life satisfaction in men with SCI.ResultsA LiSat-9 score <4, suggestive for life dissatisfaction, was exhibited by 49% of men. When compared with the life-satisfied group, a significantly higher percentage of them had sexual dissatisfaction and erectile dysfunction (ED); they also exhibited significantly lower levels of TT and calculated free testosterone (cFT) and a more severe impairment of bowel-bladder function. The life satisfaction degree correlated with sexual satisfaction degree, IIEF-5 score, TT, cFT, and bowel-bladder function degree. At the logistic regression model, including sexual LiSat-9 subscore and bowel-bladder SCIM subscore, only the former exhibited a significant negative association with life dissatisfaction. In a further logistic regression model, including the putative key determinants of sexual satisfaction, erectile function, and cFT levels, a higher odd of life dissatisfaction was independently associated both with a lower IIEF-5 score (OR: 0.93; 95% CI: 0.88, 0.98) and lower cFT levels (OR: 0.98; 95% CI: 0.98, 0.99).Clinical ImplicationsIn men with chronic SCI, assessment of erectile function and testosterone levels can help to predict life satisfaction.Strengths & LimitationsThis is the first demonstration of the independent association of androgen deficiency and ED with life satisfaction in men with SCI. Prospective studies are warranted to clarify the cause-effect relationships.ConclusionsIn men with SCI, ED and low testosterone levels exhibit a significant independent association with life dissatisfaction; longitudinal intervention studies could explore possible effects of their treatment in improving sexual and life satisfaction in this population.D'Andrea S, Minaldi E, Castellini C, et al. Independent Association of Erectile Dysfunction and Low Testosterone Levels With Life Dissatisfaction in Men With Chronic Spinal Cord Injury. J Sex Med 2020;17:911–918.     

Testosterone increases blood flow and expression of androgen and estrogen receptors in the rat vagina

IntroductionThe mechanisms by which testosterone modulates female genital sexual arousal responses are poorly understood.AimTo investigate the effects of testosterone on vaginal blood flow and the expression of estrogen and androgen receptor proteins in the rat vagina.MethodsMature female Sprague-Dawley rats were sham-operated (intact) or ovariectomized. Fourteen days after ovariectomy, animals were continuously infused with vehicle or varying doses of testosterone (5.5–55 μg/day). After 2 weeks of treatment, vaginal blood flow in response to pelvic nerve stimulation was measured by laser Doppler flowmetry. Plasma levels of testosterone and estradiol were determined by radioimmunoassay and epithelial thickness was examined in fixed vaginal tissue sections. Androgen and estrogen receptor levels were assessed by equilibrium radioligand binding and by Western blot analyses.ResultsVaginal blood flow responses were significantly reduced in ovariectomized rats and normalized in animals infused with testosterone. Ovariectomy increased the expression of estrogen receptors and reduced the expression of androgen receptors with no change in receptor-ligand affinity. Testosterone increased the expression of both androgen and estrogen receptors in the vagina. While physiological (11 μg/day) and supraphysiological (55 μg/day) concentrations of testosterone normalized vaginal tissue weight, uterine tissue and whole body weights were not significantly different from ovariectomized rats infused with vehicle. Testosterone infusion, even at supraphysiological concentrations, did not change plasma estradiol levels when compared to vehicle-infused, ovariectomized rats. Likewise, the vaginal epithelium of testosterone-infused rats remained atrophic, similar to vehicle-infused, ovariectomized rats, indicating that testosterone is not aromatized to estrogens at significant levels in the vagina.ConclusionsOur data suggest that testosterone regulates androgen and estrogen receptor protein expression in the vagina and enhances vaginal perfusion by an androgen-dependent mechanism. We conclude that testosterone plays an important role in modulating the physiology of the vagina and contributes to improvement of genital sexual arousal responses. Traish AM, Kim S Woong, Stankovic M, Goldstein I, and Kim NN. Testosterone increases blood flow and expression of androgen and estrogen receptors in the rat vagina.     

Clinical and Biopsychosocial Determinants of Sexual Dysfunction in Middle‐Aged and Older Australian Men

IntroductionErectile dysfunction (ED) and other related sexual dysfunctions in men have recently been shown to associate with a range of conditions and biopsychosocial factors. However, few studies have been able to control for these related factors simultaneously.AimTo determine the prevalence of and associated risk factors for ED and low solitary and dyadic sexual desire.Main Outcome MeasuresErectile function (International Index of Erectile Function‐erectile function) and sexual desire (Sexual Desire Inventory 2), as well as associated sociodemographic, lifestyle, biological, and clinical risk factors.MethodsData were collected from 1,195 randomly selected, community‐dwelling men as part of the Florey Adelaide Male Ageing Study.ResultsThe prevalence of ED, low solitary, and dyadic sexual desire was 17.7%, 67.7%, and 13.5%, respectively. Increasing age, abdominal fat mass, obstructive sleep apnea risk, and the absence of a regular partner were associated with both degrees of ED severity. Insufficient physical activity, low alcohol consumption, and hypertension were associated with mild ED only, and voiding lower urinary tract symptoms, diabetes, and lower plasma testosterone were independently associated with moderate to severe ED. Increasing age, lower alcohol consumption, insufficient physical activity, and a diagnosis of depression, anxiety, or insomnia were associated with both low dyadic and solitary sexual desire. Postschool qualifications and lower plasma testosterone were associated with low dyadic desire, whereas lower education and income, unemployment, and migration were associated with low solitary sexual desire. The absence of a regular partner and postschool qualifications were associated with higher solitary sexual desire.ConclusionsWhile ED and low dyadic and solitary sexual desire share some risk factors, we were able to demonstrate that unique factors exist for each of these domains. Attention should first be given to addressing these modifiable risk factors. Martin S, Atlantis E, Wilson D, Lange K, Haren MT, Taylor A, Wittert G, and Members of the Florey Adelaide Male Ageing Study. Clinical and biopsychosocial determinants of sexual dysfunction in middle‐aged and older Australian men. J Sex Med 2012;9:2093–2103.