Masturbation to Orgasm Stimulates the Release of the Endocannabinoid 2-Arachidonoylglycerol in Humans

BackgroundEndocannabinoids are critical for rewarding behaviors such as eating, physical exercise, and social interaction. The role of endocannabinoids in mammalian sexual behavior has been suggested because of the influence of cannabinoid receptor agonists and antagonists on rodent sexual activity. However, the involvement of endocannabinoids in human sexual behavior has not been studied.AimTo investigate plasma endocannabinoid levels before and after masturbation in healthy male and female volunteers.OutcomesPlasma levels of the endocannabinoids 2-arachidonoylglycerol (2-AG), anandamide, the endocannabinoid-like lipids oleoyl ethanolamide and palmitoyl ethanolamide, arachidonic acid, and cortisol before and after masturbation to orgasm.MethodsIn study 1, endocannabinoid and cortisol levels were measured before and after masturbation to orgasm. In study 2, masturbation to orgasm was compared with a control condition using a single-blinded, randomized, 2-session crossover design.ResultsIn study 1, masturbation to orgasm significantly increased plasma levels of the endocannabinoid 2-AG, whereas anandamide, oleoyl ethanolamide, palmitoyl ethanolamide, arachidonic acid, and cortisol levels were not altered. In study 2, only masturbation to orgasm, not the control condition, led to a significant increase in 2-AG levels. Interestingly, we also found a significant increase of oleoyl ethanolamide after masturbation to orgasm in study 2.Clinical TranslationEndocannabinoids might play an important role in the sexual response cycle, leading to possible implications for the understanding and treatment of sexual dysfunctions.Strengths and LimitationsWe found an increase of 2-AG through masturbation to orgasm in 2 studies including a single-blinded randomized design. The exact role of endocannabinoid release as part of the sexual response cycle and the biological significance of the finding should be studied further. Cannabis and other drug use and the attainment of orgasm were self-reported in the present study.ConclusionOur data indicate that the endocannabinoid 2-AG is involved in the human sexual response cycle and we hypothesize that 2-AG release plays a role in the rewarding consequences of sexual arousal and orgasm.Fuss J, Bindila L, Wiedemann K, et al. Masturbation to Orgasm Stimulates the Release of the Endocannabinoid 2-Arachidonoylglycerol in Humans. J Sex Med 2017;14:1372–1379.     

Cortisol,salivary alpha-amylase and children’s perceptions of their social networks

In recent years there has been a growing interest in the use of social network analysis in biobehavioral research. Despite the well-established importance of social relationships in influencing human behavior and health, little is known about how children’s perception of their immediate social relationships correlates with biological parameters of stress. In this study we explore the association between two measures of children’s personal social networks, perceived network size and perceived network density, with two biomarkers of stress, cortisol and salivary alpha-amylase. Forty children (mean age = 8.30, min age = 5, and max age = 12) were interviewed to collect information about their friendships and three samples of saliva were collected. Our results show that children characterized by a lower pre-interview cortisol concentration and a lower salivary alpha-amylase reactivity to the interview reported the highest density of friendships. We discuss this result in light of the multisystem approach to the study of children’s behavioral outcomes, emphasizing that future work of this kind is needed in order to understand the cognitive and biological mechanisms underlying children’s and adolescents’ social perceptual biases.     

Stress at three‐month immunization: Parents’ and infants’ salivary cortisol response in relation to the use of pacifier and oral glucose

The aims of the present study were to investigate (1) whether the salivary cortisol response could be dampened during a routine three‐month immunization if the infant received sweet‐tasting solution in combination with a pacifier and (2) stress experienced by parents during immunization of the infant. Ninety‐eight infants were included into one of four intervention groups: ‘glucose and pacifier’, ‘water and pacifier’, ‘glucose’, or ‘water’. Saliva was collected before and 30min after the immunization. Infants’ crying‐time and parents’ self‐reported stress (VAS) were measured before and after immunization. Infants in the ‘pacifier and glucose’ group had a significantly smaller change in salivary cortisol than infants in the other groups (F_3,72=3.1, p<0.05). In the ‘glucose and pacifier’ group the median salivary cortisol levels decreased 33% after the immunization. In the ‘water and pacifier’, ‘glucose’, and ‘water’ group median cortisol increased with 50%, 42%, and 8%, respectively. No significant differences in crying‐time were observed between the intervention groups. If the infant cried before the immunization, the crying‐time during the immunization was longer (p<0.01) and cortisol increased more (p<0.05). Median cortisol levels for parents decreased after the immunization (p<0.01). Median VAS increased 50% (p<0.0001) after immunization. First time parents rated higher stress on VAS before immunization (p<0.01). Parents’ change in cortisol and VAS were significantly related to infants’ crying time. In conclusion, the combination of oral glucose and pacifier dampen infants’ salivary cortisol in response to the three‐month immunization.     

Endocrine systems in juvenile anadromous and landlocked Atlantic salmon (Salmo salar): seasonal development and seawater acclimation

The present study compares developmental changes in plasma levels of growth hormone (GH), insulin-like growth factor I (IGF-I) and cortisol, and mRNA levels of their receptors and the prolactin receptor (PRLR) in the gill of anadromous and landlocked Atlantic salmon during the spring parr-smolt transformation (smoltification) period and following four days and one month seawater (SW) acclimation. Plasma GH and gill GH receptor (GHR) mRNA levels increased continuously during the spring smoltification period in the anadromous, but not in landlocked salmon. There were no differences in plasma IGF-I levels between strains, or any increase during smoltification. Gill IGF-I and IGF-I receptor (IGF-IR) mRNA levels increased in anadromous salmon during smoltification, with no changes observed in landlocked fish. Gill PRLR mRNA levels remained stable in both strains during spring. Plasma cortisol levels in anadromous salmon increased 5-fold in May and June, but not in landlocked salmon. Gill glucocorticoid receptor (GR) mRNA levels were elevated in both strains at the time of peak smoltification in anadromous salmon, while mineralocorticoid receptor (MR) mRNA levels remained stable. Only anadromous salmon showed an increase of gill 11beta-hydroxysteroid dehydrogenase type-2 (11beta-HSD2) mRNA levels in May. GH and gill GHR mRNA levels increased in both strains following four days of SW exposure in mid-May, whereas only the anadromous salmon displayed elevated plasma GH and GHR mRNA after one month in SW. Plasma IGF-I increased after four days in SW in both strains, decreasing in both strains after one month in SW. Gill IGF-I mRNA levels were only increased in landlocked salmon after 4days in SW. Gill IGF-IR mRNA levels in SW did not differ from FW levels in either strain. Gill PRLR mRNA did not change after four days of SW exposure, and decreased in both strains after one month in SW. Plasma cortisol levels did not change following SW exposure in either strain. Gill GR, 11beta-HSD2 and MR mRNA levels increased after four days in SW in both strains, whereas only the anadromous strain maintained elevated gill GR and 11beta-HSD2 mRNA levels after one month in SW. The results indicate that hormones and receptors of the GH and cortisol axes are present at significantly lower levels during spring development and SW acclimation in landlocked relative to anadromous salmon. These findings suggest that attenuation of GH and cortisol axes may, at least partially, result in reduced preparatory upregulation of key gill ion-secretory proteins, possibly a result of reduced selection pressure for marine adaptations in landlocked salmon.     

Confirmation that offspring from families with alcohol-dependent individuals have greater hypothalamic-pituitary-adrenal axis activation induced by naloxone compared with offspring without a family history of alcohol dependence

BACKGROUND: This study was designed to confirm our previous findings that nonalcoholic offspring from families with alcohol-dependent individuals have greater hypothalamic-pituitary-adrenal axis activation induced by opioid blockade compared with nonalcoholic subjects without a family history of alcohol dependence. METHODS: Sixty-four nonalcoholic subjects aged 18 to 25 years were enrolled in the protocol. Twenty-seven subjects were offspring from families with alcohol dependence and were designated as family history-positive subjects (FHP). Thirty-seven subjects were biological offspring of non-alcohol-dependent parents and were designated as family history-negative subjects (FHN). Subjects received naloxone hydrochloride (0, 50, 125, 375, and 500 microg/kg) in double-blind, randomized order; adrenocorticotropin (ACTH) and cortisol were monitored over 120 min. RESULTS: No hormone differences at baseline or during placebo administration were identified between FHP and FHN subjects. FHP subjects had greater ACTH and cortisol response to opioid receptor blockade induced by naloxone hydrochloride compared with FHN subjects. CONCLUSIONS: These observations confirm previous findings that differences in ACTH and cortisol dynamics between FHP and FHN subjects can be unmasked by opioid receptor blockade.     

Effects of licorice on plasma atrial natriuretic peptide in healthy volunteers

Ingestion of licorice, 100 g daily for 8 weeks, caused a rise in 81% in plasma atrial natriuretic peptide (ANP) concentration in 12 healthy subjects. Mean body weight increment (1.6 kg) correlated with the increase in plasma ANP (r = 0.59; P less than 0.01). The plasma concentrations of antidiuretic hormone, aldosterone, and plasma renin activity decreased. All these hormonal effects, reflecting retention of sodium and fluid volume, were probably due to the known mineralocorticoid properties of licorice. Blood pressure increased transiently and two subjects developed reversible hypertension. The rise in plasma ANP concentration during ingestion of licorice may be considered a physiological response to prevent fluid retention and development of hypertension.     

Urinary free cortisol excretion shortly after ischaemic stroke

The cortisol axis and catecholamine excretion were studied in 20 patients within the first week after acute ischaemic stroke. Urine free cortisol and plasma cortisol levels after dexamethasone were significantly higher in stroke patients than in 80-year-old volunteers (n = 32; P = 0.03 and P = 0.003, respectively). Catecholamine excretion was found to be significantly correlated with urine cortisol concentration (r = 0.54, P less than 0.05) and limb paresis (r = 0.52, P less than 0.05). In a multiple regression analysis, urine cortisol values were shown to be positively associated with limb paresis (P = 0.003), disorientation (P = 0.03) and body temperature (P = 0.03). High cortisol excretion was associated with a poorer functional outcome in a discriminant analysis (P = 0.001). Thus acute ischaemic stroke is associated with an increased activity in the cortisol axis. This may have a number of negative effects on organ functioning, and is a predictor of a poorer functional outcome.     

Personality and physiological reactions to acute psychological stress

Stable personality traits have long been presumed to have biological substrates, although the evidence relating personality to biological stress reactivity is inconclusive. The present study examined, in a large middle aged cohort (N = 352), the relationship between key personality traits and both cortisol and cardiovascular reactions to acute psychological stress. Salivary cortisol and cardiovascular activity were measured at rest and in response to a psychological stress protocol comprising 5 min each of a Stroop task, mirror tracing, and a speech task. Participants subsequently completed the Big Five Inventory to assess neuroticism, agreeableness, openness to experience, extraversion, and conscientiousness. Those with higher neuroticism scores exhibited smaller cortisol and cardiovascular stress reactions, whereas participants who were less agreeable and less open had smaller cortisol and cardiac reactions to stress. These associations remained statistically significant following adjustment for a range of potential confounding variables. Thus, a negative personality disposition would appear to be linked to diminished stress reactivity. These findings further support a growing body of evidence which suggests that blunted stress reactivity may be maladaptive.     

Longitudinal associations in adolescence between cortisol and persistent aggressive or rule-breaking behavior

Although several studies have associated antisocial behavior with decreased cortisol awakening responses (CAR), studies in adolescent samples yielded inconsistent results. In adolescence however, the CAR develops and antisocial behavior is heterogeneous in type and persistence. Therefore this longitudinal study compared persistent aggressive and rule-breaking adolescents to low aggressive and rule-breaking adolescents on the development of the CAR from ages 15 to 17 (N = 390). Persistently high aggressive adolescents showed decreased cortisol levels at awakening consistently over the years (Δχ²(1) = 6.655, p = .01) as compared to low aggressive adolescents. No differences between adolescents showing persistent high rule-breaking and low rule-breaking were found. This longitudinal study is the first to show that persistent aggression, but not rule-breaking behavior, is related to neurobiological alterations. Moreover, despite development of the CAR over adolescence, the decrease in cortisol is consistent over time in persistent high aggressive adolescents, which is an important prerequisite for the prediction of persistent aggression.