Absence of orgasm-induced prolactin secretion in a healthy multi-orgasmic male subject

In several studies we have recently demonstrated that orgasm induces prolactin secretion in healthy males and females. This suggests that prolactin may form a feedback regulator of the refractory period following orgasm. To examine this position we investigated the prolactin response of a healthy multi-orgasmic male subject. Blood was drawn continuously during masturbation-induced orgasm. The prolactin response of the case-subject was compared with that of nine healthy adult men with a normal refractory period. The case-subject showed no prolactin response to three orgasms. Data from this multi-orgasmic subject support the hypothesized role of plasma prolactin in contributing to sexual-satiation mechanisms.     

Changes in the hypothalamic-pituitary-gonadal axis in men after cadaver kidney transplantation and cyclosporine therapy.

A variety of plasma androgens, estradiol, follicle-stimulating hormone, luteinizing hormone, prolactin, cortisol, and thyroid parameters were examined in 10 men followed serially before and after cadaver kidney transplantation. Before transplantation, plasma testosterone levels were below normal in 8 of the 10 men. Free testosterone, follicle-stimulating hormone, and luteinizing hormone were at the lower range of normal values, yet plasma estradiol levels were elevated 3-fold, and prolactin levels were also high. One month after transplantation, all hormones measured were suppressed, probably reflecting high-dose steroids and multiple-drug regimens used in the period following the operation. After 3 months, when other immunosuppressants were reduced and cyclosporine dosage was stabilized, plasma testosterone, androgens, follicle-stimulating hormone, and luteinizing hormone levels were restored toward normal. After 12 months, plasma testosterone levels exceeded pretransplant levels. Plasma estradiol and prolactin levels dramatically decreased after transplantation and remained in the normal range thereafter. These data indicate that abnormalities of plasma estradiol and prolactin levels observed in patients with end-stage renal disease are restored toward normal after cadaver kidney transplantation. Androgen levels that were suppressed in the period immediately after transplantation were restored to normal levels in the succeeding months despite chronic usage of cyclosporine, suggesting that cyclosporine, in currently used doses, does not prevent the restoration of the hypothalamic-pituitary-testicular axis.     

Prolactinergic and dopaminergic mechanisms underlying sexual arousal and orgasm in humans

Dopaminergic mechanisms play a major role in modulating sexual behavior in humans and animals. Animal data demonstrate important interactions between the dopaminergic and prolactinergic system. As recently demonstrated, dopamine agonists have facilitatory properties for penile erection but may also enhance sexual drive and orgasmic quality. In contrast, chronic elevations of prolactin inhibit appetitive as well as consummatory parameters of sexual behavior. Recent human studies show a marked increase in prolactin after orgasm in males and females. Concerning the biological relevance of acute prolactin alterations after orgasm, prolactin might serve as a neuroendocrine reproductive reflex for peripheral reproductive organs. Alternatively, prolactin may feedback to dopaminergic neurons in the central nervous system and thereby modulate sexual drive and satiation. Here, we provide a brief overview of the physiology of dopamine and prolactin in regulating sexual behavior. In addition, recent experimental and clinical evidence for a postulated feedback mechanism for prolactin and its implications for orgasmic disorders are discussed.     

Testosterone levels after bromocriptine treatment in patients undergoing long-term hemodialysis

Seventeen out of 34 male patients undergoing long-term hemodialysis had increased basal plasma prolactin levels (mean = 1344 +/- 1158.76 mU/L). Seven of these 17 patients having the greatest degree of erectile impotence were treated with 3.5 to 7.5 mg/day of bromocriptine. After a 4-week treatment period, basal plasma prolactin levels in all seven patients were within normal limits (mean = 210.2 +/- 66.97 mU/L). The treated patients reported an improvement in both libido and potency. At the same time, an increase in plasma testosterone levels was observed, while plasma LH and FSH levels were essentially unchanged.     

Testosterone therapy in women: its role in the management of hypoactive sexual desire disorder

Disorders of sexual dysfunction occur in nearly half of women during their life, and hypoactive sexual desire disorder accounts for most of those complaints. Although the relationship between low endogenous testosterone levels and sexual desire disorders in women has not been empirically established, clinical trials have shown that exogenous testosterone therapy improves arousability, sexual desire and fantasy, frequency of sexual activity and orgasm, and satisfaction and pleasure from the sexual act. Its therapeutic role in bone mineral density, fatigue, well-being and hot flashes requires more study before specific recommendations can be made. Potential adverse effects of testosterone therapy include hirsutism, acne and deepening of the voice along with changes in lipid profiles. While less well understood, concern after increased risks for breast cancer and cardiovascular events has been raised about this therapy. Testosterone therapy is available in various formulations; the most commonly used are oral and transdermal, including patches, gels, creams and ointments.     

Zinc deficiency and hyperprolactinaemia are not reversible causes of sexual dysfunction in uraemia

We selected a group of male dialysis patients complaining of sexual dysfunction in whom penile vascular insufficiency and drug-induced impotence had been excluded. Monitoring of nocturnal penile tumescence was used to confirm organic disturbance. Patients with normal serum prolactin concentrations (n = 18) had significantly lower serum zinc values than normal controls (P less than 0.001) and were entered in a 6-month double-blind study comparing oral zinc acetate with placebo. Patients with elevated prolactin concentrations (n = 8) were entered in a 3-month double-blind crossover study comparing oral pergolide mesylate with placebo. In the zinc study, serum zinc concentrations increased (P less than 0.05) in the zinc-treated but not the placebo-treated group. One of nine patients receiving zinc reported improved sexual function, as did two of nine patients receiving placebo. There were no significant changes in sperm counts, nocturnal penile tumescence, testosterone, sex hormone binding globulin or gonadotrophin concentrations in either treatment group. In the pergolide study, serum prolactin values decreased (P less than 0.01) in the pergolide but not in the placebo treatment period. One patient reported improved sexual function during the pergolide treatment period and two during the placebo period. There were no significant changes in sperm counts, nocturnal penile tumescence, testosterone, sex hormone binding globulin or gonadotrophin concentrations after pergolide. These studies show no benefit of zinc or pergolide compared with placebo in the treatment of uraemic impotence.     

Effects of long-term testosterone administration on pituitary-testicular axis in end-stage renal failure

The endocrine effects of long-term testosterone administration were studied in 6 end-stage renal failure patients. During a 3-month control period where no androgens were administered the mean plasma testosterone level (7.3 nmol/l) was depressed while mean plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH), and prolactin (PRL) levels were elevated at 41.2 mU/ml, 105.5 mU/ml, and 63 ng/ml, respectively. These values were repeated during a 6-month study period where each subject was administered testosterone enanthate (400 mg) intramuscularly once a week. Plasma testosterone levels markedly increased in all subjects with a mean elevation of 72.4 nmol/l, while reductions were observed in FSH and LH levels with values of 2.7 and 16.3 mU/ml, respectively. When compared with control period values, these changes were statistically significant (p less than 0.05). Although the mean plasma PRL level of 49.0 ng/ml was reduced when compared with the control period values, this reduction was not statistically significant. Our control period findings of low plasma testosterone levels coupled with high plasma LH and FSH are consistent with Leydig cell dysfunction. The significant reductions in plasma FSH and LH noted during the study period indicate a negative feedback effect produced by the pharmacologic doses of testosterone. Long-term testosterone administration, however, did not significantly affect the elevated mean PRL levels observed in these subjects.     

Function of Endocrine Organs in Hemodialyzed Patients of Long-Term Erythropoietin Therapy

Abstract: Endocrine abnormalities in patients with chronic renal failure are well documented. The present study aimed to assess the influence of long-term erythropoietin (EPO) therapy on endocrine abnormalities in hemodialyzed patients. Two groups of hemodialyzed patients, each of which comprised 17 subjects, were examined. The first group was treated by EPO (EPO group) while the second one did not receive this hormone (No-EPO group). A complete biochemical and hormonal check-up was performed before and at the 3, 6, 9, and 12 month points of the study period. Normal values for the estimated parameters were obtained in appropriately selected sex- and age-matched healthy subjects. After EPO therapy, an increase of the hematocrit value from 21.8 ± 0.9 to 32.6 ± 0.9% was observed, which was accompanied by a significant decline of plasma ferritin and saturation of transferrin. In patients of the No-EPO group, a significant although less marked rise of the hematocrit value (21.4 ± 0.4 to 24.2 ± 0.6%) was also noticed. EPO therapy did not change plasma levels of electrolytes (Na, K, Ca, inorganic phosphate), osteocalcin, creatinine, glucose, and alkaline phosphatase as well as plasma concentrations of calcium-related hormones (PTH, calcitonin, 1,25[OH]₂D₃), vasopressin, and triiodothyronine. EPO treatment induced a significant decrease in somatotropin, prolactin, follitropin, lutropin, ACTH, cortisol, plasma renin activity, aldosterone, noradrenaline, adrenaline, dopamine, glucagon, pancreatic polypeptide, and gastrin plasma levels and an increase in plasma insulin, estradiol, testosterone, atrial natriuretic peptide, thyrotropin, and thyroxine. These EPO-induced endocrine alterations were restricted mostly to the first 6 months of EPO administration. In patients of the No-EPO group, a significant decrease in the plasma levels of prolactin, noradrenaline, and dopamine and an increase of estradiol plasma levels were also noticed during the 1-year study period. Therefore, long-term treatment by EPO shows profound effects on the function of several endocrine organs. These effects are transitory and predominantly restricted to the first 6 months of EPO therapy. Not all endocrine alterations observed in EPO-treated patients seem to be due to the administration of this hormone.     

Evidence for the association between blood prolactin and androgen receptors in BPH

The purpose of this study was to investigate the relationship between prostatic androgen receptors and plasma prolactin and testosterone in patients with benign prostatic hyperplasia. Cytosolic and KCl extractable nuclear androgen receptors were measured in 22 patients and these were in turn correlated to the hormone concentrations in blood specimens taken on the morning before the day of operation. The mean +/- S.E.M. concentrations of cytoplasmic androgen receptors, KCl extractable nuclear androgen receptors, plasma testosterone and plasma prolactin were respectively 115 +/- 18 fmoles/gm. tissue, 198 +/- 40 fmoles/gm. tissue, 15.6 +/- 1.2 nmol./l. and 128 +/- 17 mU/l. Plasma prolactin was highly correlated with cytosolic androgen receptors (r = 0.784, p less than 0.01; no. = 15) though not with nuclear androgen receptors (r = 0.453, p greater than 0.05; no. = 15). However, when the androgen receptor levels were expressed as fmoles/mg. protein both cytosolic and nuclear levels were proportional to plasma prolactin (p less than 0.01 and p less than 0.02 for both the cytosolic and nuclear receptors respectively; no. = 15). There was no correlation between either cytosolic and nuclear androgen receptors and plasma testosterone levels. The results suggest that plasma prolactin may be involved in the regulation of androgen receptor content in the benign prostate.     

Effect of continuous versus delayed insulin replacement on sex behavior and neuroendocrine function in diabetic male rats

The ability of insulin replacement to reverse the adverse effects of streptozocin-induced diabetes (STZ-D) on neuroendocrine and sexual function was tested in adult male rats. Rats were injected with STZ (50 mg/kg) or vehicle and then either started immediately on insulin (continuous) or allowed to remain untreated for 4 wk before insulin replacement was started (delayed). Replacement consisted of 5 IU/kg of insulin injected just before the lights were turned off and 2 IU/kg of insulin injected within 1 h of the lights being turned on. Copulatory behavior was tested 2, 4, 5, and 6 wk after induction of diabetes. Forty-five days after STZ administration, rats were killed for measurement of plasma hormone levels and hypothalamic catecholamine turnover and serotonin content. The STZ-D rats showed significant deficits in mount, intromission, and ejaculatory behaviors that were prevented by continuous insulin replacement. Delayed insulin replacement reversed the deficits in mount and intromission behaviors but not ejaculatory behavior. Plasma luteinizing hormone levels were unaffected by STZ or insulin treatment, but plasma testosterone and prolactin levels were both reduced in the diabetic animals. Continuous or delayed insulin replacement normalized both testosterone and prolactin levels. Median eminence, medial basal hypothalamus, anterior hypothalamus, and olfactory bulb rates of norepinephrine turnover were all reduced after STZ administration. Delayed insulin replacement restored norepinephrine turnover in all brain regions, whereas continuous insulin replacement enhanced norepinephrine turnover in the anterior hypothalamus and olfactory bulb but only partially blocked the effects of STZ in the median eminence and medial basal hypothalamus.(ABSTRACT TRUNCATED AT 250 WORDS)     

Sexual dysfunction in women with hyperprolactinemia: a pilot study report

PURPOSE: Hyperprolactinemia is a common hormonal disorder in women that may affect the phases of female sexual function (FSD). We investigated sexual function in patients with hyperprolactinemia. MATERIAL AND METHODS: A total of 25 women with primary hyperprolactinemia and 16 age matched voluntary healthy women who served as the as control group were evaluated with a detailed medical and sexual history, including a female sexual function index (FSFI) questionnaire and the Beck Depression Inventory. Serum prolactin, dehydroepiandrosterone sulfate, free testosterone, androstenedione, 17alpha-hydroxyprogesterone, estradiol, free thyroxin and thyrotropin were measured. These variables were compared statistically between the 2 groups. RESULTS: Except for prolactin serum hormone levels in women with hyperprolactinemia were not different from those in the control group. The median total FSFI score was 23.40 (IQR 17.70 to 27.30) in the hyperprolactinemic group, whereas healthy women had a median total FSFI score of 31.10 (IQR 27.55 to 32.88, p < 0.0001). FSD was diagnosed in 22 of 25 patients (88%), while 4 of 16 healthy women (25%) had FSD (p = 0.03). Desire (p = 0.001), arousal (p < 0.0001), lubrication (p = 0.001), orgasm (p = 0.001), satisfaction (p = 0.07) and pain (p = 0.003) domain scores were also significantly lower in women with hyperprolactinemia. Total FSFI (p = 0.009, r = -0.405), desire (p = 0.001, r = -0.512), arousal (p = 0.002, r = -0.466), orgasm (p = 0.026, r = 0.348) and satisfaction (p = 0.041, r = -0.320) scores negatively correlated with mean prolactin but not with the other hormones measured. CONCLUSIONS: A significant percent of women with hyperprolactinemia whom we evaluated had sexual dysfunction. No hormonal changes other than prolactin and no depression was found as a cause of FSD.     

Semen characteristics and diabetes mellitus: significance of insulin in male infertility

A study was made of semen quality and serum hormonal profiles (FSH, LH, prolactin, testosterone) of patients with type I diabetes mellitus. Semen parameters and levels of prolactin and testosterone were significantly altered in the diabetic state. The concentration of insulin in serum and seminal plasma and the serum levels of FSH, LH, and testosterone were measured in 80 men classified in the following groups: fertile subjects, infertile normoglycemic subjects, subjects with carbohydrate intolerance, and excretory and secretory azoospermic subjects. In all groups, seminal insulin concentrations were higher than those obtained in serum. The hormone appears to freely cross the blood-testis barrier, there to be concentrated in the semen. The levels of insulin in serum and seminal plasma did not correlate with semen parameters and are not suitable markers of seminal quality. For unknown reasons, the concentrations of insulin in seminal plasma were lower in the subjects suffering from carbohydrate intolerance.     

Laparoscopic cholecystectomy: haemodynamic and neuroendocrine responses after pneumoperitoneum and changes in position

We have assessed the potential for myocardial ischaemia during laparoscopic cholecystectomy in 16 otherwise healthy patients. Continuous ambulatory ECG monitoring was commenced 12 h before operation and continued for 24 h after operation. The neuroendocrine stress response was assessed by measuring plasma concentrations of adrenaline and noradrenaline, human growth hormone, cortisol, renin and aldosterone, and prolactin, at specified times during surgery. Acute ST segment changes in the ECG occurred in only two patients. These episodes were independent of creation of pneumoperitoneum and changes in position. Acute intraoperative increases in MAP were noted during insufflation of carbon dioxide and reverse Trendelenburg positioning (P < 0.05). A four-fold increase in plasma concentrations of renin and aldosterone was noted after pneumoperitoneum and reverse Trendelenburg positioning (P > 0.05). There was a linear correlation between changes in plasma renin and aldosterone concentrations and MAP (r = 0.97 and r = 0.85, respectively). Prolactin concentrations increased four-fold after induction of anaesthesia. Cortisol, HGH, adrenaline and noradrenaline concentrations increased after deflation of the pneumoperitoneum. The time profile-concentration changes of increased MAP and renin-aldosterone suggests a cause-effect relationship. Increased intra-abdominal pressure and reverse Trendelenburg positioning may reduce cardiac output and renal blood flow. The early increase in prolactin concentration was probably secondary to the effect of the opioid fentanyl.      

Influence of lisuride, a dopaminergic agonist, on the sexual function of male patients with chronic renal failure

The effects of Lisuride, a dopaminergic agonist, on the levels of plasma prolactin (PRL), testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and on the variations of libido and coital frequency of patients with chronic renal failure (CRF) have been investigated in a group of 20 male patients (ten normoprolactinemic and ten hyperprolactinemic). Ten patients were included in a hemodialysis program and another ten received conservation therapy (all had creatinine clearance rates below 15 mL/min). The response of PRL to TRH administration and that of LH and FSH to LH-RH administration have also been studied. Low levels of plasma testosterone found initially in all the patients, increased in both normoprolactinemic (P less than 0.05) and hyperprolactinemic patients (P less than 0.01) during Lisuride administration. PRL decreased (P less than 0.01) in both groups during therapy. The increase of plasma testosterone was greater in hyperprolactinemic patients (86% v 15% in normoprolactinemic) and was accompanied by a clear improvement in the studied parameters of sexual behaviors. The response of PRL to TRH was modified in hyperprolactinemic patients while that of LH and FSH to LH-RH was not modified, although Lisuride induced an increase of the basal value of LH (P less than 0.01) in the hyperprolactinemic group. The drug was fairly well tolerated, did not induce hypotension, and the overall incidence of side effects decreased along the study. These results stress the need for further studies with this agent in patients with chronic renal failure and sexual dysfunction.     

Bromocriptine for infertile males with mild hyperprolactinemia: hormonal and spermatogenic effects

To clarify the influence of hyperprolactinemia on spermatogenesis and steroidogenesis in infertile male patients, the serum prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, and estradiol concentrations were and the effect of bromocriptine treatment on spermatogenesis was examined. A total of 1234 patients were evaluated and 147 men had hyperprolactinemia. Of these, only 30 had PRL concentrations more than twice the upper limit of normal and most of them had a little excess over the upper limit. For 10 of these 30, serum hormone concentrations were measured and semen was analyzed before and after bromocriptine administration. No relationship between the PRL and other hormone concentrations was found. No changes were noted in the LH, FSH, testosterone, or estradiol concentrations, or in the sperm density and motility after treatment. The mean PRL decreased from 26.5 +/- 4.5 to 1.4 +/- 1.8 ng/mL. In infertile men who are mildly hyperprolactinemic, bromocriptine administration does not improve semen analysis, although it does normalize the PRL.     

Increased plasma and pituitary prolactin concentrations in adult male rats with selective elevation of FSH levels may be explained by reduced testosterone and increased estradiol production

The roles of testosterone and estradiol in regulating prolactin concentrations were studied in acutely castrated adult male rats receiving subcutaneous Silastic implants of the sex steroids. Testosterone was administered in increasing doses, from subphysiologic to intact levels, both alone and in combination with a small, single dose of estradiol. The study was designed to assess whether a change in the relative rates of sex steroid production could account for an increase in PRL release in the absence of other testicular factors. At very low levels of plasma testosterone, FSH and LH levels were indistinguishable from castrate controls. As plasma testosterone concentration increased, both plasma FSH and LH levels were suppressed progressively to intact levels. When a subphysiologic dose of testosterone was coadministered with a small dose of estradiol, the combined effects produced a midcastrate level of FSH but maintained a normal level of LH similar to the selective increase in FSH concentration observed in men with germinal aplasia. Although PRL levels were indistinguishable in intact and castrate controls, testosterone replacement by capsule increased prolactin in a dose-related manner so that, at the physiologic level of testosterone, prolactin was elevated two-fold (P less than 0.01), similar to the level achieved with estradiol replacement alone. Pituitary prolactin levels also increased with increasing doses of testosterone but values remained within the range measured in intact controls. When estradiol was coadministered with testosterone, the combination produced different effects depending on the testosterone dose.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of chronic sulpiride-induced hyperprolactinemia on plasma testosterone and its responses to hCG in normal men

To elucidate the effects of sulpiride-induced (300 mg daily) long-term (64 days) hyperprolactinemia on basal and hCG-stimulated plasma testosterone (T), hCG was given to five normal men five times at 2-week intervals (before sulpiride administration and at 2, 4, 6 and 8 weeks). Mean integrated hCG responses of plasma T did not change significantly as compared with baseline. However, mean (+/- SEM) basal plasma levels of T decreased significantly (P less than 0.05) from 1011 +/- 148 ng/dl to 852 +/- 13 at 2 weeks, 520 +/- 53 at 4 weeks, 572 +/- 137 at 6 weeks and 554 +/- 140 at 8 weeks. These results suggest that sulpiride-induced hyperprolactinemia (73.8 ng/ml, the average of mean values obtained at 2, 4, 6 and 8 weeks) for 64 days does not suppress secretion of T in response to hCG in spite of a decrease in basal plasma T concentrations. It is unlikely that the low concentrations of plasma T are due to direct effects of hyperprolactinemia on the testis.     

The effects of sulfasalazine on human male fertility potential and seminal prostaglandins

Fertility parameters of 10 men with chronic inflammatory bowel disease under treatment with sulfasalazine for at least 5 years were compared to those of 19 control subjects. Seminal parameters examined included ejaculate volume, sperm number and concentration, sperm motility index, sperm viability, pH, zinc concentration, prostaglandins E and F2-alpha, prolactin and 7 classes of sperm morphology. In addition, plasma concentrations of follicle-stimulating hormone, luteinizing hormone, testosterone and prolactin were noted. The data indicate that sulfasalazine therapy reduces semen quality and that this effect can be reversed upon removal from therapy. This reversal is independent of seminal prostaglandin concentrations.     

基于女性性反应增敏的阴蒂暴露术及其对性生活的影响

目的 探讨基于女性性反应增敏的阴蒂暴露术对女性性生活的影响。方法 选取我院2021年1月-6月 收治的35例求美者作为研究对象，由同一手术项目组操作；通过阴蒂暴露术将阴蒂暴露1/3；观察手术前 及术后6个月求美者阴蒂勃起时间及女性性功能指数量表（FSFI）、女性性苦恼量表（FSDS-R）评分。 结果 85.71%求美者阴蒂高潮提前，8.57%表示阴蒂高潮无明显变化，5.71%表示阴蒂敏感度较前下降；术 后6个月FSFI评分为（25.93±2.72）分，高于术前的（24.31±3.43）分（P＜0.05）；术后6个月FSDS-R评分 为（22.89±6.45）分，低于术前的（25.31±7.07）分（P ＜0.05）。结论 基于性反应增敏的阴蒂暴露术能提 升求美者阴蒂性敏感度，有效提高女性性生活满意度，值得在临床应用。     

Chronic immobilization-induced stress increases plasma testosterone and delays testicular maturation in pubertal rats

We investigated whether chronic stress, applied from prepuberty to early puberty, interferes with the spermatogenic and androgenic testicular functions. Male pubertal rats (40 days old) were immobilized 6 h per day for 15 days. Plasma concentrations of corticosterone, prolactin and testosterone were significantly augmented following immobilization, whereas plasma luteinizing hormone decreased and follicle-stimulating hormone was not altered. Acute immobilization (5 min) increased prolactin and testosterone levels in control rats but caused a significantly higher increase in these hormones when superimposed on chronic stress. A lower extent of testicular maturation was observed in pubertal rats immobilized from prepuberty.