Impact of estrogen receptor α gene and oxytocin receptor gene polymorphisms on female sexuality

The relationship between OXT gene polymorphisms and reproductive hormones in pregnant and lactating Awassi Ewes

BACKGROUND

Numerous genetic loci interact intricately to control reproduction in mammals. The oxytocin gene (OXT) is a promising candidate for reproductive traits in mammals. Previously, sheep and goats have been studied for the presence of the OXT polymorphism. As of yet, no polymorphisms have been identified in the OXT gene of Awassi sheep. Thus, this study was conducted to determine the effects of OXT polymorphism and litter size on reproductive hormones in pregnant and lactating Awassi ewes.

METHODS AND RESULTS

This study evaluated 232 ewes aged 3 and 4 years (123 single-progeny ewes and 109 twin-producing ewes). Serum was collected to measure reproductive hormones using ELISA kits manufactured by ELK Biotechnology. DNA was extracted from sheep blood for genotyping and sequencing to identify variations in OXT gene (exon 2, 266 bp). Genotyping analysis revealed three genotypes within 266 bp: CC, CA, and AA. Sequence analysis revealed a novel mutation in exon 2: 188 C > A. Statistical analysis showed significant associations between the 188 C > A SNP and phenotypic traits. Twin-pregnant ewes carrying CC genotypes had higher estrogen, progesterone, and follicle-stimulating hormone/luteinizing hormone levels (65.86 ± 3.87) (pg/mL), (6.51 ± 0.39) (ng/mL), and (20.22 ± 1.27) (ng/mL)/( 23.37 ± 2.14) (ng/mL) respectively, compared to CA and AA genotypes in the fourth month of twin-pregnant ewes compared to single-pregnant ewes.

CONCLUSIONS

This study found that the 188 C > A SNP negatively affected reproductive hormone levels in Awassi sheep. These findings provide breeders with a new insight into the sheep OXT gene, useful for future breeding.

Event-Related Potentials in Women on the Pill: Neural Correlates of Positive and Erotic Stimulus Processing in Oral Contraceptive Users

Background/Aims: Exposure toward positive emotional cues with - and without - reproductive significance plays a crucial role in daily life and regarding well-being as well as mental health. While possible adverse effects of oral contraceptive (OC) use on female mental and sexual health are widely discussed, neural processing of positive emotional stimuli has not been systematically investigated in association with OC use. Considering reported effects on mood, well-being and sexual function, and proposed associations with depression, it was hypothesized that OC users showed reduced neural reactivity toward positive and erotic emotional stimuli during early as well as later stages of emotional processing and also rated these stimuli as less pleasant and less arousing compared to naturally cycling (NC) women. Method: Sixty-two female subjects (29 NC and 33 OC) were assessed at three time points across the natural menstrual cycle and corresponding time points of the OC regimen. Early (early posterior negativity, EPN) and late (late positive potential, LPP) event-related potentials in reaction to positive, erotic and neutral stimuli were collected during an Emotional Picture Stroop Paradigm (EPSP). At each appointment, subjects provided saliva samples for analysis of gonadal steroid concentration. Valence and arousal ratings were collected at the last appointment. Results: Oral contraceptive users had significantly lower endogenous estradiol and progesterone concentrations compared to NC women. No significant group differences in either subjective stimulus evaluations or neural reactivity toward positive and erotic emotional stimuli were observed. For the OC group, LPP amplitudes in reaction to erotic vs. neutral pictures differed significantly between measurement times across the OC regimen. Discussion: In this study, no evidence regarding alterations of neural reactivity toward positive and erotic stimuli in OC users compared to NC was found. Possible confounding factors and lines for future research are elaborated and discussed.

Impaired Sexual Function in Young Women With PCOS: The Detrimental Effect of Anovulation

BACKGROUND

Even though polycystic ovary syndrome (PCOS) is a common reproductive disorder affecting young women, its impact on their sexual health is not well known.

AIM

To examine the different aspects of female sexuality in young women with PCOS and attempt to associate hormonal changes and ovulatory status with their sexual function.

METHODS

Anthropometric characteristics, hormonal levels and sexual function based on the Female Sexual Function Index (FSFI) questionnaire were assessed in 76 young women with PCOS and 133 matched controls.

OUTCOMES

Sexual function is significantly impaired in young women with PCOS.

RESULTS

Women with PCOS demonstrated lower scores than controls in arousal (5.04 ± 1.19 vs 4.48 ± 1.44, P < .001), lubrication (5.29 ± 1.17 vs 4.69 ± 1.54, P < .001), orgasm (4.78 ± 1.40 vs 4.11 ± 1.61, P = .001), satisfaction (5.22 ± 1.10 vs 4.78 ± 1.31, P = .016), and total score of the FSFI (29.51 ± 5.83 vs 26.76 ± 6.81, P < .001), even after correction for BMI. When corrected for total testosterone, the domains of lubrication, satisfaction, and total score of FSFI remained significantly impaired in women with PCOS (P values .037, .024, & .044 respectively). In multivariate logistic regression analysis, after adjusting for the effect of BMI and hormone levels, dysfunction in orgasm, satisfaction and the total FSFI score were still 3-4 times more common in PCOS (adjusted OR [95% CI]: 3.54, P = .020; 2.96, P = .050; 3.87, P = .027). Even though no statistically significant differences were observed between women with ovulatory PCOS and controls, we detected statistically significant differences in all domains of sexual function apart from pain between controls and PCOS women with anovulation (desire P value .04, arousal P value <.001, lubrication P value <.001, orgasm P value .001, satisfaction P value .001 and FSFI total score P value <.001).

CLINICAL IMPLICATIONS

Women with PCOS have compromised sexual function, which is independent of their BMI and highly dependent on their ovulatory status.

STRENGTHS AND LIMITATIONS

This is the first study in women with PCOS that implicates anovulation as a risk factor for sexual impairment in PCOS. Further studies are needed to elucidate the mechanisms implicated and to examine the effect of PCOS therapy on the patients' sexual function.

CONCLUSION

The adverse effect of PCOS status on the female sexual function is independent of BMI and only partially dependent on hormonal changes characterizing the syndrome. Anovulation appears to be the major determinant of sexual impairment among women with PCOS. Mantzou D, Stamou MI, Armeni AK, et al. Impaired Sexual Function in Young Women With PCOS: The Detrimental Effect of Anovulation. J Sex Med 2021;18:1872-1879.

Estrogenic regulation of social behavior and sexually dimorphic brain formation

It has long been known that the estrogen, 17β-estradiol (17β-E), plays a central role for female reproductive physiology and behavior. Numerous studies have established the neurochemical and molecular basis of estrogenic induction of female sexual behavior, i.e., lordosis, in animal models. In addition, 17β-E also regulates male-type sexual and aggressive behavior. In males, testosterone secreted from the testes is irreversibly aromatized to 17β-E in the brain. We discuss the contribution of two nuclear receptor isoforms, estrogen receptor (ER)α and ERβ to the estrogenic regulation of sexually dimorphic brain formation and sex-typical expression of these social behaviors. Furthermore, 17β-E is a key player for social behaviors such as social investigation, preference, recognition and memory as well as anxiety-related behaviors in social contexts. Recent studies also demonstrated that not only nuclear receptor-mediated genomic signaling but also membrane receptor-mediated non-genomic actions of 17β-E may underlie the regulation of these behaviors. Finally, we will discuss how rapidly developing research tools and ideas allow us to investigate estrogenic action by emphasizing behavioral neural networks.

Revisiting the wandering womb: Oxytocin in endometriosis and bipolar disorder

Hippocrates attributed women's high emotionality - hysteria - to a 'wandering womb'. Although hysteria diagnoses were abandoned along with the notion that displaced wombs cause emotional disturbance, recent research suggests that elevated levels of oxytocin occur in both bipolar disorder and endometriosis, a gynecological condition involving migration of endometrial tissue beyond the uterus. We propose and evaluate the hypothesis that elevated oxytocinergic system activity jointly contributes to bipolar disorder and endometriosis. First, we provide relevant background on endometriosis and bipolar disorder, and then we examine evidence for comorbidity between these conditions. We next: (1) review oxytocin's associations with personality traits, especially extraversion and openness, and how they overlap with bipolar spectrum traits; (2) describe evidence for higher oxytocinergic activity in both endometriosis and bipolar disorder; (3) examine altered hypothalamic-pituitary-gonadal axis functioning in both conditions; (4) describe data showing that medications that treat one condition can improve symptoms of the other; (5) discuss fitness-related impacts of endometriosis and bipolar disorder; and (6) review a pair of conditions, polycystic ovary syndrome and autism, that show evidence of involving reduced oxytocinergic activity, in direct contrast to endometriosis and bipolar disorder. Considered together, the bipolar spectrum and endometriosis appear to involve dysregulated high extremes of normally adaptive pleiotropy in the female oxytocin system, whereby elevated levels of oxytocinergic activity coordinate outgoing sociality with heightened fertility, apparently characterizing, overall, a faster life history. These findings should prompt a re-examination of how mind-body interactions, and the pleiotropic endocrine systems that underlie them, contribute to health and disease.