Stress responses to bacterial and viral mimetics in polycystic ovary syndrome model rats.

Polycystic ovary syndrome (PCOS) is associated with an increased risk of psychological distress as well as enhanced responses to psychosocial stress. Recently, it was hypothesized that PCOS patients may be at high risk of novel COVID-19 infections and worse clinical presentations during such infections. Here, we evaluated the effects of PCOS on stress responses to bacterial and viral mimetics using dihydrotestosterone-induced PCOS model rats. Lipopolysaccharide (LPS; a bacterial mimetic) or polyinosinic-polycytidylic acid (Poly-IC; a viral mimetic) was injected into PCOS model rats (PCOS) and non-PCOS rats (control), and the rats' stress responses were evaluated. In the PCOS group, the rats' anorectic and febrile responses to LPS injection were enhanced, whereas their anorectic and febrile responses to Poly-IC injection were unaltered. The PCOS group also exhibited greater changes in peripheral cytokine levels in response to LPS, but not Poly-IC. On the contrary, after the injection of Poly-IC depressed locomotor activity was more evident in the PCOS group, whereas no such changes were observed after LPS injection. These findings indicate that although the stress responses of PCOS model rats to infection may be enhanced, the patterns of change in stress responses and their underlying mechanisms may differ between bacterial and viral infections.

Progesterone treatment reduces food intake and body weight in ovariectomized female rats.

While the effects of progesterone on body weight and appetite in pre-menopausal conditions have been well elucidated, its effects in post-menopausal conditions have not been clarified. On the contrary, the effects of estrogen on body weight and appetite in post-menopausal conditions have been well established. In this study, the effects of progesterone treatment on body weight, appetite, and fat mass in ovariectomized rats were evaluated. In addition, the central and/or peripheral levels of oxytocin (OT), leptin, and their receptors, which are potent anorectic factors, were examined. Female rats were ovariectomized and divided into control, progesterone-treated, and estrogen-treated groups. Body weight, food intake, and subcutaneous fat mass were lower in both the progesterone and estrogen groups than in the control group. The estrogen group exhibited higher serum OT levels than the control group, whereas the OT levels of the progesterone and control groups did not differ. The serum leptin levels of both the progesterone and estrogen groups were lower than those of the control group. Gene expression analysis of OT, leptin, and their receptors in the hypothalamus and adipose tissue found few significant differences among the groups. Hypothalamic neuropeptide Y (NPY) and pro-opiomelanocortin (POMC) mRNA levels involved in appetite regulation were slightly altered in the progesterone and estrogen groups. These findings suggest that progesterone treatment may have favorable effects on body weight, appetite, and fat mass regulation in post-menopausal conditions and that the mechanisms underlying these effects of progesterone differ from those underlying the effects of estrogen.

Oncologic, fertility, and obstetric outcomes with MPA therapy in women with endometrial cancer and atypical endometrial hyperplasia.

AIM: Medroxyprogesterone acetate (MPA) is one of the treatments of atypical endometrial hyperplasia (AEH) and endometrial cancer (EC) to preserve the fertility. Efficacy of MPA therapy and fertility and obstetric outcomes after remission were evaluated in EC or AEH patients. METHODS: Among patients diagnosed with EC or AEH at Tokushima University Hospital between January 2002 and October 2020, we retrospectively analyzed patients, ages range from 26 to 40, who underwent conservative management using MPA (400-600 mg/day). RESULTS: In total, 19 patients underwent MPA therapy. The 18 (94%) patients achieved complete response (CR), and 1 (5%) patient achieved partial response (PR). Relapse occurred in 6 (32%) patients who had achieved CR. Of the patients who relapsed, 4 patients resumed MPA therapy and were in remission. Among 19 patients, 13 patients attempted pregnancy after CR. All of them underwent ovulation induction or assisted reproductive technology. As a result, 20 pregnancies in 10 (77%) patients and 12 live births in 9 (69%) patients were achieved. Rate of spontaneous abortion was 35% (7/20). CONCLUSIONS: MPA therapy can produce a high remission rate, and be considered an effective treatment for patients who wish fertility preservation. Around 70% patients who attempt to pregnancy can have at least one baby by infertility treatments. Because recurrence rate after MPA therapy is high, it may be desirable to aim for early pregnancy by active intervention.

Age-Dependent Changes in the Effects of Androgens on Female Metabolic and Body Weight Regulation Systems in Humans and Laboratory Animals.

In recent years, the effects of androgens on metabolic and body weight regulation systems and their underlying mechanisms have been gradually revealed in females. In women and experimental animals of reproductive age, androgen excess can adversely affect metabolic functioning, appetite, and body weight regulation. In addition, excess androgens can increase the risk of metabolic disorders, such as obesity, insulin resistance, and diabetes. These unfavorable effects of androgens are induced by alterations in the actions of hypothalamic appetite-regulatory factors, reductions in energy expenditure, insulin resistance in skeletal muscle, and ß-cell dysfunction. Interestingly, these unfavorable effects of androgens on metabolic and body-weight regulation systems are neither observed nor evident in ovariectomized animals and post-menopausal women, indicating that the adverse effects of androgens might be dependent on the estrogen milieu. Recent findings may provide novel sex- and age-specific strategies for treating metabolic diseases.

Compatible cut-off values for luteinizing hormone and the luteinizing hormone/follicle-stimulating hormone ratio in diagnostic criteria of the Japan Society of Obstetrics and Gynecology for polycystic ovary syndrome.

AIM: The abnormal secretion of luteinizing hormone (LH) is one of the typical features of polycystic ovary syndrome (PCOS) and adopted in the diagnostic criteria of the Japan Society of Obstetrics and Gynecology (JSOG). We investigated cut-off values for LH and the LH/follicle-stimulating hormone (FSH) ratio in resent two measurement systems for the diagnosis of PCOS. METHODS: Ninety-nine controls and 106 patients with PCOS were enrolled. Serum LH and FSH levels were measured using an electrochemiluminescence immunoassay (ARCHITECT) and chemiluminescence immunoassay (ECLusys). We examined the distribution of the measured levels, selected the conversion closest to the standard normal distribution in the control group, and calculated mean + 1 SD values for LH and the LH/FSH ratio as candidates. Cut-off values coincided with the medians of the candidates in the two assay systems using a regression equation. We calculated the endocrinological abnormality rate in PCOS according to the JSOG criteria by abnormal LH secretion and elevated T. RESULTS: Cut-off values for LH (mIU/mL) and the LH/FSH ratio were 7.1 and 1.21, respectively, in ARCHITECT, and 9.9 and 1.51, respectively, in ECLusys. The detection rates of endocrinological abnormalities in PCOS were 72.2% and 70.6% in the nonoverweight/obese PCOS group and overweight/obese PCOS group, respectively, in ARCHITECT, and 69.4% and 73.5%, respectively, in ECLusys. CONCLUSION: We obtained cut-off values of LH and the LH/FSH ratio for diagnostic criteria of JSOG criteria for PCOS, that were highly compatible between two major assay systems. These cut-off values will contribute to the diagnosis of PCOS in Japan and presumably in women of Asian ethnicities.

Changes in Serum Oxytocin Levels under Physiological and Supraphysiological Gonadal Steroid Hormone Conditions in Women of Reproductive Age: A Preliminary Study.

Oxytocin (OT) affects many behavioral, psychological, and physiological functions, including appetite and body weight regulation. Central and peripheral OT levels are markedly affected by gonadal steroids, especially estrogen, and the anorectic effects of estrogen are partially mediated by OT in rodents. In this study, the relationship between the estrogen milieu and serum OT levels was evaluated in women of reproductive age under physiological (n = 9) and supraphysiological estrogenic conditions (n = 7). Consequently, it was found that serum OT levels were increased in physiological (the ovulatory phase) and supraphysiological (on the day of the human chorionic gonadotropin trigger in an ovarian stimulation cycle) estrogenic conditions, and that serum OT levels were positively correlated with serum estradiol levels. On the other hand, serum OT levels were negatively correlated with serum progesterone levels, and there was no correlation between serum and follicular OT levels. These results suggest that OT levels may be positively and negatively regulated by estrogen and progesterone, respectively, in humans. However, the physiological roles of these actions of gonadal steroids on OT remain unclear.

Effects of undernutrition and low energy availability on reproductive functions and their underlying neuroendocrine mechanisms.

It has been well established that undernutrition and low energy availability disturb female reproductive functions in humans and many animal species. These reproductive dysfunctions are mainly caused by alterations of some hypothalamic factors, and consequent reduction of gonadotrophin-releasing hormone (GnRH) secretion. Evidence from literature suggests that increased activity of orexigenic factors and decreased activity of anorexigenic/satiety-related factors in undernourished conditions attenuate GnRH secretion in an integrated manner. Likewise, the activity of kisspeptin neurons, which is a potent stimulator of GnRH, is also reduced in undernourished conditions. In addition, it has been suggested that gonadotrophin-inhibitory hormone, which has anti-GnRH and gonadotrophic effects, may be involved in reproductive dysfunctions under several kinds of stress conditions. It should be remembered that these alterations, i.e., promotion of feeding behavior and temporary suppression of reproductive functions, are induced to prioritize the survival of individual over that of species, and that improvements in metabolic and nutritional conditions should be considered with the highest priority.

Is a freeze-all strategy necessary for all embryo transfers†: Fresh embryo transfer without progesterone elevation results in an equivalent pregnancy rate to cryopreserved embryo transfer.

Objectives : It has been suggested that the clinical outcomes of frozen-thawed embryo transfer (ET) are superior to those of fresh embryo transfer. We examined whether a freeze-all strategy is necessary for all embryo transfers, and, if not, to evaluate the conditions in which the pregnancy rates of fresh embryo transfer and frozen-thawed ET did not differ. Methods : Patients who underwent blastocyst transfer at Tokushima University Hospital between 2008 and 2019 were enrolled. The clinical outcomes and clinical characteristics of 1,022 patients that underwent fresh embryo transfer and 1,728 patients that underwent frozen-thawed ET were examined retrospectively. We considered the factors that influenced the pregnancy outcomes of fresh embryo transfer. Results : The frozen-thawed ET group exhibited significantly higher pregnancy, live-birth, and miscarriage rates than the fresh embryo transfer group. In the fresh embryo transfer group, a high progesterone level on the day of the human chorionic gonadotropin (hCG) trigger and lower grade embryos were risk factors for a low pregnancy rate. However, in the cases in which the progesterone level was < 1.0 ng / mL the pregnancy rate was equal to that of frozen-thawed ET. Conclusions : A freeze-all strategy is not necessary for embryo transfers, but should be employed in cases involving pre-ovulatory progesterone elevation. J. Med. Invest. 69 : 224-229, August, 2022.

Changes in Endogenous Oxytocin Levels and the Effects of Exogenous Oxytocin Administration on Body Weight Changes and Food Intake in Polycystic Ovary Syndrome Model Rats.

Polycystic ovary syndrome (PCOS) is frequently seen in females of reproductive age and is associated with metabolic disorders that are exacerbated by obesity. Although body weight reduction programs via diet and lifestyle changes are recommended for modifying reproductive and metabolic phenotypes, the drop-out rate is high. Thus, an efficacious, safe, and continuable treatment method is needed. Recent studies have shown that oxytocin (OT) reduces body weight gain and food intake, and promotes lipolysis in some mammals, including humans (especially obese individuals), without any adverse effects. In the present study, we evaluated the changes in endogenous OT levels, and the effects of acute and chronic OT administration on body weight changes, food intake, and fat mass using novel dihydrotestosterone-induced PCOS model rats. We found that the serum OT level was lower in PCOS model rats than in control rats, whereas the hypothalamic OT mRNA expression level did not differ between them. Acute intraperitoneal administration of OT during the dark phase reduced the body weight gain and food intake in PCOS model rats, but these effects were not observed in control rats. In contrast, chronic administration of OT decreased the food intake in both the PCOS model rats and control rats. These findings indicate that OT may be a candidate medicine that is efficacious, safe, and continuable for treating obese PCOS patients.

Biotin levels in blood and follicular fluid and their associations with pregnancy outcomes in IVF/ICSI patients.

It has been shown that biotin, a water-soluble vitamin (B7), plays roles in reproductive functions, such as oocyte maturation and embryo development, in experimental animals. On the other hand, little is known about the clinical effects of biotin on human reproduction. In this study, serum and follicular fluid biotin levels were measured in patients who underwent in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), and their associations with reproductive outcomes were evaluated. As a result, biotin was detected in follicular fluid, as well as serum, and the biotin levels of follicular fluid were found to be positively correlated with those of serum. The biotin levels of serum were higher than those of follicular fluid, suggesting that biotin may be taken up into the follicular fluid from the blood. Although serum and follicular fluid biotin levels tended to be higher in pregnant patients than in non-pregnant patients, these data did not show the significant statistical difference. These findings indicate that biotin does not contribute to the maintenance of oocyte quality, and hence, it does not increase fertilization and pregnancy rates. J. Med. Invest. 69 : 65-69, February, 2022.

Neuroendocrine mechanisms of reproductive dysfunctions in undernourished condition.

It is well known that undernourished conditions disturb female reproductive functions in many species, including humans. These alterations are mainly caused by a reduction in gonadotrophin-releasing hormone (GnRH) secretion from the hypothalamus. Evidence from the literature suggests that some hypothalamic factors play pivotal roles in the coordination of reproductive functions and energy homeostasis in response to environmental cues and internal nutritional status. Generally, anorexigenic/satiety-related factors, such as leptin, alpha-melanocyte-stimulating hormone, and proopiomelanocortin, promote GnRH secretion, whereas orexigenic factors, such as neuropeptide Y, agouti-related protein, orexin, and ghrelin, attenuate GnRH secretion. Conversely, gonadotrophin-inhibitory hormone, which exerts anti-GnRH and gonadotrophic effects, promotes feeding behavior in many species. In addition, the activity of kisspeptin, which is a potent stimulator of GnRH, is reduced by undernourished conditions. Under normal nutritional conditions, these factors are coordinated to maintain both feeding behavior and reproductive functions. However, in undernourished conditions their activity levels are markedly altered to promote feeding behavior and temporarily suppress reproductive functions, in order to prioritize the survival of the individual over that of the species.

A novel PCOS rat model and an evaluation of its reproductive, metabolic, and behavioral phenotypes.

BACKGROUND: Although animal models of PCOS have been used in many studies, none of them can reproduce both the reproductive and metabolic phenotypes of PCOS. In addition, behavioral parameters have not been evaluated in PCOS animal models. PURPOSE: We tried to produce an improved rat model of PCOS, and the reproductive, metabolic, and behavioral phenotypes of the model rats were evaluated. METHODS: Female rats were implanted with silicon tubes containing oil-dissolved dihydrotestosterone (Oil-DHT) as a new PCOS model. Their phenotypes were compared with those of conventional PCOS model rats (DHT), into which tubes containing crystalline DHT were implanted, and non-DHT-treated rats (control). RESULTS: Both the Oil-DHT and DHT rats showed greater body weight gain, food intake, and fat depot weight than the control rats. Furthermore, these groups showed fewer estrous stages and increased numbers of cystic follicles. The DHT rats exhibited lower ovarian and uterine weights than the control rats, whereas no such changes were observed in the Oil-DHT rats. The Oil-DHT and DHT rats showed less locomotor activity in the light phase than the control rats. CONCLUSIONS: Our proposed PCOS model reproduced both the reproductive and metabolic phenotypes of PCOS and may have potential for PCOS research.

Effects of low energy availability on female reproductive function.

BACKGROUND: It is known that metabolic and nutritional disturbances induce reproductive dysfunction in females. The main cause of these alterations is reduced gonadotrophin-releasing hormone (GnRH) secretion from the hypothalamus, and the underlying mechanisms have gradually been elucidated. METHODS: The present review summarizes current knowledge about the effects of nutrition/metabolism on reproductive functions, especially focusing on the GnRH regulation system. MAIN FINDINGS: Various central and peripheral factors are involved in the regulation of GnRH secretion, and alterations in their activity combine to affect GnRH neurons. Satiety-related factors, i.e., leptin, insulin, and alpha-melanocyte-stimulating hormone, directly and indirectly stimulate GnRH secretion, whereas orexigenic factors, i.e., neuropeptide Y, Agouti-related protein, orexin, and ghrelin, attenuate GnRH secretion. In addition, kisspeptin, which is a potent positive regulator of GnRH, expression is reduced by metabolic and nutritional disturbances. CONCLUSION: These neuroendocrine systems may be defensive mechanisms, which help organisms to survive adverse conditions by temporarily suppressing reproduction.

The effects of androgens on metabolic functions in females.

The metabolic effects of androgens and their underlying mechanisms in females have been revealed by recent studies. An excess of androgens can have adverse effects on feeding behavior and metabolic functions and induce metabolic disorders / diseases, such as obesity, insulin resistance, and diabetes, in women and experimental animals of reproductive age. Interestingly, these effects of androgens are not observed in ovariectomized animals, indicating that their effects might be dependent on the estrogen milieu. Central and peripheral mechanisms, such as alterations in the activity of hypothalamic factors, reductions in energy expenditure, skeletal muscle insulin resistance, and ß-cell dysfunction, might be related to these androgens' effects. J. Med. Invest. 68 : 228-231, August, 2021.

Effects of gonadal status and the estrogen milieu on hypothalamic oxytocin gene expression and serum oxytocin levels in female rats.

Oxytocin (OT) and its receptor (OTR) play various roles in the central and peripheral regulation of appetite and body weight. Previously, we have shown that the administration of OT markedly decreased appetite and body weight gain in ovariectomized (OVX) obese rats. In addition, recent studies have shown that the endogenous OT system is also affected by endogenous or exogenous estrogen. In this study, we showed that ovariectomy decreased rats' hypothalamic OT/OTR mRNA and serum OT levels, but did not affect their visceral fat OTR mRNA levels. The chronic administration of estradiol (E2) abrogated these ovariectomy-induced changes; i.e., it increased the rats' hypothalamic OT/OTR mRNA and serum OT levels, and may be associated with reductions in food intake and body weight gain. In addition, acute E2 administration increased the rats' hypothalamic OTR mRNA and serum OT levels, but did not affect their hypothalamic OT mRNA levels. Taken together, these results suggest that endogenous OT and/or OTR expression might be positively regulated by E2 and that the suppressive effects of E2 on appetite and body weight gain might be mediated, at least in part, by the OT system. Thus, we consider that OT might be a target hormone to pursue subsequent interventions of menopause for menopause-induced metabolic disorders.

The reduction in sexual behavior of adult female rats exposed to immune stress in the neonatal period is associated with reduced hypothalamic progesterone receptor expression.

PURPOSE: We examined the mechanism by which neonatal immune stress reduces the sexual behavior of female rats in adulthood. METHODS: Neonatal female rats were randomly divided into 3 groups: control (n = 11), postnatal day 10 lipopolysaccharide (PND10LPS) (n = 23), and PND25LPS (n = 11) groups, which received intraperitoneal injections of LPS (100 µg/kg) or saline on PND10 and 25. Daily inspections of the vaginal opening (VO) were performed from PND27 to PND37. Thereafter, the frequency of estrus was assessed for 15 days. Female rats (at 11-12 weeks of age) were placed in a cage with male rats, and their sexual behavior was monitored for 30 min. The hypothalamic mRNA expression levels of factors related to sexual behavior were examined via real-time PCR. RESULTS: VO occurred later and the frequency of estrus was lower in the PND10LPS group compared to the control group. The number of lordosis behaviors and the total number of mounts performed by male partners were lower in the PND10LPS and PND25LPS groups than in the control group. Acceptability: The lordosis quotient and lordosis rating were lower in the PND10LPS group than in the control group. Proceptive behavior: the number of ear wiggling events was lower in the PND10LPS group than in the other groups, and the number of hops/darts was lower in the PND10LPS group than in the control group. The hypothalamic mRNA expression level of progesterone receptors (PR)A + B was lower in the PND10LPS group than in the control group, and the hypothalamic PRB mRNA expression level was lower in the PND10LPS and PND25LPS groups than in the control group. CONCLUSION: Neonatal immune stress impeded sexual behavior and hypothalamic PR mRNA expression in female rats. Decreased progesterone activity in the hypothalamus might explain the reduction in sexual behavior seen in these rats.