Androgen excess increases food intake in a rat polycystic ovary syndrome model by down-regulating hypothalamus insulin and leptin signaling pathways preceding weight gain

2021 ◽  
Author(s):  
Ying Liu ◽  
Yu-chen Xu ◽  
Yu-gui Cui ◽  
Shi-wen Jiang ◽  
Fei-yang Diao ◽  
...  

Background Polycystic ovary syndrome (PCOS) is a common reproductive and metabolic disorder characterized by high androgen levels. The aim of this study was to evaluate the effects of hyperandrogenism on the hypothalamus, and subsequently on the food intake and obesity in females. Methods A dihydroxy testosterone (DHT)-induced rat model was established to recapitulate the hyperandrogenism features of PCOS patients. Body weight and food intake of the rats were recorded. The food intake of DHT-induced rats was restricted by pair feeding to exclude possible effects of weight gain on the hypothalamus. The expression levels of relevant proteins and mRNAs in the hypothalamus, primary hypothalamic neurons exposed to DHT were analyzed by Western blotting and RT-PCR respectively. The leptin levels in serum and cerebrospinal fluid (CSF) were measured, and leptin was injected via the intracerebroventricular (ICV) route to test the leptin sensitivity of hypothalamus. Results The excessive pre-puberty androgen levels in the DHT-induced rats markedly elevated food intake prior to weight gain. Consistent with this, the expression of NPY and Agouti-related peptide (Agrp) mRNAs were up-regulated, which occurred prior to obesity and even with restricted food intake. In addition, the hypothalamic sensitivity to insulin and leptin was also impaired in the DHT-induced rats before obesity and with restricted food intake. DHT significantly reduced the leptin levels in the CSF, and ICV injection of leptin inhibited the DHT-induced increase in food intake. Conclusions Androgen excess increased food intake in rats and promoted obesity by down-regulating insulin and leptin signaling in the hypothalamus, most likely by suppressing leptin levels in the CSF.

2005 ◽  
Vol 5 (4) ◽  
pp. 142-146 ◽  
Author(s):  
Cynthia L. Harden

Polycystic ovary syndrome (PCOS) is a mysterious reproductive disorder that results in subfertility. The underlying causes are not known, and even the definition is a moving target. Women with epilepsy have features of PCOS at a higher than expected rate, and polycystic ovaries (PCO) also are present at high rates in this population. Valproate is associated with weight gain and increased androgen levels, two features of PCOS. This review proposes that epilepsy, with its known adverse effects on luteinizing hormone pulsatility, could be a cause of PCOS and that valproate could be an imitator, if not also a cause of the syndrome.


2008 ◽  
Vol 4 (6) ◽  
pp. 583-594 ◽  
Author(s):  
Charikleia D Christakou ◽  
Evanthia Diamanti-Kandarakis

Polycystic ovary syndrome (PCOS) is associated with a clustering of metabolic and cardiovascular risk factors. Insulin resistance is implicated as the major player in the metabolic abnormalities and contributes to the increased cardiovascular risk associated with the syndrome. However, androgen excess appears to participate as an independent parameter, which further aggravates the cardiovascular and metabolic aberrations in affected women with PCOS. The resultant impact of hyperandrogenemia possibly acquires clinical significance for women's health in the context of PCOS, particularly since recent data support an increased incidence of coronary artery disease and of cardiovascular events directly related to androgen levels in women with the syndrome.


2008 ◽  
Vol 93 (7) ◽  
pp. 2909-2912 ◽  
Author(s):  
Mark O. Goodarzi ◽  
Ning Xu ◽  
Ricardo Azziz

Abstract Context: Adrenal androgen excess is common in polycystic ovary syndrome (PCOS) and appears to be heritable. CYP3A7 metabolizes dehydroepiandrosterone and its sulfate (DHEAS). A promoter variant, CYP3A7*1C, which results in persistent expression in adults, was associated with reduced DHEAS levels in a previous study, which led us to consider CYP3A7*1C as a modulator of adrenal androgen excess in patients with PCOS. Objective: The objective was to replicate the association between CYP3A7*1C and reduced DHEAS levels in PCOS patients and assess its possible role in modulating testosterone levels. Design: Women with and without PCOS were genotyped for CYP3A7*1C, and this variant was tested for association with DHEAS and total and free testosterone. Setting: Subjects were recruited from the reproductive endocrinology clinic at the University of Alabama at Birmingham; controls were recruited from the surrounding community. Genotyping took place at Cedars-Sinai Medical Center (Los Angeles, CA). Participants: A total of 287 white women with PCOS and 187 controls were studied. Main Measurements: CYP3A7*1C genotype, PCOS risk, and androgen levels were measured. Results: PCOS subjects who carried the CYP3A7*1C variant had lower levels of serum DHEAS and total testosterone (P = 0.0006 and 0.046, respectively). The variant was not associated with PCOS risk. Conclusion: This study replicated prior work of the association of CYP3A7*1C and decreased DHEAS in a different population of young PCOS women, providing further genetic evidence that CYP3A7 plays a potential role in modulation of DHEAS levels. Adult expression of CYP3A7 may modify the PCOS phenotype by ameliorating adrenal androgen excess.


2011 ◽  
Vol 18 (2) ◽  
pp. 146-170 ◽  
Author(s):  
H.F. Escobar-Morreale ◽  
E. Carmina ◽  
D. Dewailly ◽  
A. Gambineri ◽  
F. Kelestimur ◽  
...  

2007 ◽  
Vol 92 (12) ◽  
pp. 4546-4556 ◽  
Author(s):  
Kelsey E. S. Salley ◽  
Edmond P. Wickham ◽  
Kai I. Cheang ◽  
Paulina A. Essah ◽  
Nicole W. Karjane ◽  
...  

Endocrinology ◽  
2015 ◽  
Vol 156 (11) ◽  
pp. 4071-4080 ◽  
Author(s):  
Amanda Hurliman ◽  
Jennifer Keller Brown ◽  
Nicole Maille ◽  
Maurizio Mandala ◽  
Peter Casson ◽  
...  

This study was designed to differentiate the contributions of hyperandrogenism, insulin resistance (IR), and body weight to the development of endothelial dysfunction in polycystic ovary syndrome and determine the effectiveness of insulin sensitization and antiandrogenic therapy after the establishment of vascular and metabolic dysfunction using a rat model of polycystic ovary syndrome. We hypothesized that the observed endothelial dysfunction was a direct steroidal effect, as opposed to changes in insulin sensitivity or body weight. Prepubertal female rats were randomized to the implantation of a pellet containing DHT or sham procedure. In phase 1, DHT-exposed animals were randomized to pair feeding to prevent weight gain or metformin, an insulin-sensitizing agent, from 5 to 14 weeks. In phase 2, DHT-exposed animals were randomized to treatment with metformin or flutamide, a nonsteroidal androgen receptor blocker from 12 to 16 weeks. Endothelial function was assessed by the vasodilatory response of preconstricted arteries to acetylcholine. Serum steroid levels were analyzed in phase 1 animals. Fasting blood glucose and plasma insulin were analyzed and homeostasis model assessment index calculated in all animals. Our data confirm the presence of endothelial dysfunction as well as increased body weight, hypertension, hyperinsulinemia, and greater IR among DHT-treated animals. Even when normal weight was maintained through pair feeding, endothelial dysfunction, hyperinsulinemia, and IR still developed. Furthermore, despite weight gain, treatment with metformin and flutamide improved insulin sensitivity and blood pressure and restored normal endothelial function. Therefore, the observed endothelial dysfunction is most likely a direct result of hyperandrogenism-induced reductions in insulin sensitivity, as opposed to weight gain.


2021 ◽  
Vol 50 (Supplement_1) ◽  
Author(s):  
Mamaru Ayenew Awoke ◽  
Arul Earnest ◽  
Anju Joham ◽  
Allison Hodge ◽  
Wendy Brown ◽  
...  

Abstract Background Women with polycystic ovary syndrome (PCOS) have a higher prevalence of overweight/obesity and greater weight gain than women without PCOS. The association of lifestyle factors with weight change in PCOS is not known. Methods We used data from the 1973-78 birth cohort of the Australian Longitudinal Study on Women’s Health collected from seven surveys over 19 years (N = 14127 survey 1). Linear mixed-effects models were used to examine associations between diet, physical activity, and sitting time with weight change, after adjustment for socio-demographics, psychological factors, and health care utilisation. Results Women with PCOS gained more weight annually (0·26 kg/year, 95% CI 0·13, 0·39; P < 0·0001) and over 19 years (4·75 kg; 95% CI 3·17, 6·34; P < 0·0001) than women without PCOS (adjusted analyses). For all women, there were positive associations between weight gain and energy intake, sitting time, and stress; inverse associations with fibre intake and physical activity; and no associations with diet quality, glycemic index, healthcare utilization, depression, or anxiety. There were interactions between lifestyle factors (energy intake P = 0·006, glycemic index P = 0·007, sitting time P = 0·029, and physical activity P = 0·022), PCOS status and time (age) such that weight gain varied between women with and without PCOS according to these factors. Conclusions Women with PCOS had a higher rate of weight gain than women without PCOS. This was most marked in those with indicators of unhealthy lifestyles. Increased stress, energy intake and sitting time and lower physical activity contributed to weight gain in women with and without PCOS. Key messages The findings reinforce the importance of early and ongoing lifestyle intervention and the potential use of specific lifestyle factors for weight gain prevention and management in PCOS.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A803-A804
Author(s):  
Jacob E Pruett ◽  
Steven Everman ◽  
Edgar David Torres Fernandez ◽  
Kacey Davenport ◽  
Damian G Romero ◽  
...  

Abstract Introduction: Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age. PCOS is characterized by androgen excess and ovulatory dysfunction high prevalence of cardiovascular risk factors such as increased blood pressure (BP), insulin resistance (IR), and obesity. We have demonstrated previously that exposing prepubertal female rats to dihydrotestosterone (DHT) leads to increase in food intake (FI), body weight (BW), BP, and IR. We tested the hypothesis that administration of the AR blocker bicalutamide (BICA) would decrease BP, IR, and obesity in PCOS model. As there are previous reports of severe hepatotoxicity with the AR blocker flutamide, we also examined BICA effects in the liver. Methods: Four-week old female Sprague Dawley rats implanted with DHT pellets (7.5mg/90 days) or placebo (PBO) were randomized to standard chow diet with or without the AR blocker bicalutamide (BICA) at a dose of 250 mg/kg/day throughout the study (n=10/group). BW and FI were measured weekly. BP and heart rate (HR) were measured by radiotelemetry. Fasting plasma was collected for IR (Homeostatic model assessment for IR, HOMA-IR). At euthanasia, the liver was collected, as well as plasma for gamma glutamyl transferase (GGT), alanine transaminase (ALT), and aspartate transaminase (AST) quantification. Results: PCOS rats had increased BW, FI, IR, and BP compared to PBO. BICA treatment had no impact on BW (285.3 ± 7.0 vs 270 ± 8.2 g, P=0.2) as well as FI and HR in PCOS. However, in PCOS, BICA decreased HOMA-IR (5.10 ± 0.40 vs 3.33 ± 0.31, P<0.05) and BP (115.4 ± 0.7 vs 105.3 ± 0.2 mmHg, P<0.01). Compared to PBO, PCOS+BICA rats had similar IR (3.83 ± 0.28 vs 3.33 ± 0.31, P=0.7) and BP (107.4 ± 0.8 vs 105.3 ± 0.2 mmHg, P=0.9). In addition, the liver weight to tibia length ratio was drastically increased by BICA in PCOS (222.9 ± 9.5 vs 360.4 ± 16.9 mg/mm, P<0.0001) as well as GGT (0.88 ± 0.88 vs 11.67 ± 0.58 U/L, P<0.0001), though it decreased AST (60.2 ± 6.9 vs 42.4 ± 1.9 U/L, P<0.05) and had no impact on ALT. Conclusion: In summary, in a model of PCOS, BICA treatment abolished IR and BP, independent of FI, BW and HR. Prompt treatment with an AR blocker can normalize increased IR and BP triggered by androgen excess in females. Further studies need to be done to fully understand the effect of BICA in the liver in PCOS. The beneficial effect of AR blockers as a therapeutic option to improve the cardiometabolic profile in PCOS may be hampered by its liver toxicity.


Sign in / Sign up

Export Citation Format

Share Document