Beta-cell compensation and gestational diabetes.

Gestational diabetes mellitus (GDM) is characterized by glucose intolerance in pregnant women without a previous diagnosis of diabetes. While the etiology of GDM remains elusive, the close association of GDM with increased maternal adiposity and advanced gestational age implicates insulin resistance as a culpable factor for the pathogenesis of GDM. Pregnancy is accompanied by the physiological induction of insulin resistance in the mother secondary to maternal weight gain. This effect serves to spare blood glucose for the fetus. To overcome insulin resistance, maternal ß-cells are conditioned to release more insulin into the blood. Such an adaptive response, termed ß-cell compensation, is essential for maintaining normal maternal metabolism. ß-cell compensation culminates in the expansion of ß-cell mass and augmentation of ß-cell function, accounting for increased insulin synthesis and secretion. As a result, a vast majority of mothers are protected from developing GDM during pregnancy. In at-risk pregnant women, ß-cells fail to compensate for maternal insulin resistance, contributing to insulin insufficiency and GDM. However, gestational ß-cell compensation ensues in early pregnancy, prior to the establishment of insulin resistance in late pregnancy. How ß-cells compensate for pregnancy and what causes ß-cell failure in GDM are subjects of investigation. In this mini-review, we will provide clinical and preclinical evidence that ß-cell compensation is pivotal for overriding maternal insulin resistance to protect against GDM. We will highlight key molecules whose functions are critical for integrating gestational hormones to ß-cell compensation for pregnancy. We will provide mechanistic insights into ß-cell decompensation in the etiology of GDM.

Acetate causes renoprotection like androgen and mineralocorticoid receptors blockade in testosterone-exposed pregnant rats.

The kidney plays a critical role in human health and deviation from its normal function can lead to severe morbidity and mortality. Exposure to excess testosterone in women has been linked to several disorders, including kidney disorder and acting undoubtedly through androgen receptor (AR), whereas the involvement of mineralocorticoid receptor (MR) is unclear. Likewise, the renal effect of sodium acetate (SAc) during late gestational exposure to testosterone is not well known. We hypothesized that SAc or MR blockade would protect the kidney of testosterone-exposed pregnant rats against glutathione and adenosine depletion. Twenty-five pregnant Wistar rats were treated (sc) with olive oil, testosterone propionate (0.5 mg/kg) singly or in combination with SAc (200 mg/kg; p.o.), androgen receptor (AR) blocker, flutamide (Flu; 7.5 mg/kg; p.o.) or (MR) blocker, eplerenone (Eple; 0.5 mg/kg) between gestational days 14 and 19. Glutathione, adenosine and nitric oxide were decreased while uric acid (UA), xanthine oxidase (XO), malondialdehyde (MDA), lactate dehydrogenase activity and free fatty acids were increased in the kidneys of gestational rats exposed to testosterone. Also, plasma urea and creatinine were elevated. SAc and Eple reversed tested testosterone-induced effects in gestational rats. The exposure to testosterone impairs renal antioxidant defense via AR and MR during late gestation in pregnant rats. The study also provides evidence that sodium acetate protects the kidneys of gestational testosterone-exposed rats against defective antioxidant defense in like manner as MR or AR antagonist.

Ameliorative effect of low-dose spironolactone on obesity and insulin resistance is through replenishment of estrogen in ovariectomized rats.

Women have a lower incidence of cardiovascular diseases (CVD) than men at a similar age but the reverse is the case after menopause, indicating a possible protective effect of estrogen on cardiometabolic function. Although various hormonal therapies have been formulated to combat the CVD risks in postmenopausal state, the beneficial effects have not been consistent. Obesity with insulin resistance (IR) is closely linked to CVD risks while ovariectomized rodents have been shown to mimic a state of obesity and IR. We therefore hypothesized that low-dose spironolactone would ameliorate obesity and IR in estrogen-deprived rats by replenishing estrogen and suppressing elevated glycogen synthase kinase-3 (GSK-3). Ten-week-old female Wistar rats were divided into 4 groups: sham-operated (SHM), spironolactone (SPL; 0.25 mg/kg), and ovariectomized (OVX) rats treated with or without spironolactone daily for 8 weeks. Results showed that estrogen deprivation through ovariectomy caused increased body mass gain and visceral adiposity that are accompanied by increased HOMA-IR, HOMA-ß, 1-hour postload glucose, glucose intolerance, platelet/lymphocyte ratio, plasma insulin, atherogenic dyslipidemia, uric acid, GSK-3, corticosterone, and aldosterone and depressed 17ß-estradiol. However, treatment of OVX rats with spironolactone ameliorated all these effects. Taken together, the results demonstrate that treatment with low-dose spironolactone improves obesity and IR, which appears to involve replenishment of estrogen and suppression of GSK-3 along with circulating mineralocorticoid and glucocorticoid. The findings imply a positive cardiometabolic effect of low-dose spironolactone usage in estrogen-deprived conditions.

High salt intake does not aggravate glucose dysregulation and dyslipidemia induced by estrogen-progestin oral contraceptive.

BACKGROUND: Estrogen-progestogen combined oral contraceptive (OC) use has been associated with increased cardiometabolic risk factors, including glucose dysregulation, dyslipidemia, hypertension, and pro-inflammatory state. However, the effect of a high-salt diet on these risk factors during OC use is not yet investigated. We therefore hypothesized that a high-salt diet would increase cardiometabolic risk factors in female rats treated with a combination of OC steroids, levonorgestrel (L) and ethinylestradiol (EE), and that elevated plasma levels of pro-inflammatory markers are associated with the cardiometabolic effects. METHODS: Female Wistar rats were given (p.o.) vehicle, high-dose (1.0µg EE plus 5.0µgL) or low-dose (0.1µg EE plus 0.5µgL) OC with or without a high-salt diet (8%) daily for 8 weeks. Insulin resistance (IR) was estimated using the homeostatic model of assessment (HOMA). RESULTS: Results showed that OC treatment or high salt diet led to significant increases in insulin resistance, plasma insulin, total cholesterol (TC), triglyceride (TG), TC/HDL-cholesterol, uric acid levels, and decreased glucose tolerance. OC treatment but not a high-salt diet resulted in increased plasma C-reactive protein and TG/HDL-cholesterol. However, a high-salt diet did not aggravate the effects of OC treatment. CONCLUSION: The results from the present study indicate that glucose dysfunction and dyslipidemia induced by OC use, but not those induced by increased dietary salt are associated with elevated plasma C-reactive protein. Besides, increased dietary salt does not worsen abnormal cardiometabolic impact of OC use.

Depletion of hepatic glutathione and adenosine by glucocorticoid exposure in Wistar rats is pregnancy-independent.

Liver diseases have gained increasing attention due to their substantial impact on health, independently as well as in association with cardio-metabolic disorders. Studies have suggested that glutathione and adenosine assist in providing protection against oxidative stress and inflammation while glucocorticoid (GC) therapy has been associated with chronic inflammatory disorders, even in pregnancy. The implications of Glucocorticoid exposure on maternal health and fetal growth is a concern, however, the possible role of glutathione and adenosine has not been thoroughly investigated. The study therefore hypothesize that exposure to glucocorticoids leads to depletion of hepatic glutathione and adenosine levels, contributing to oxidative stress and tissue injury. Additionally, we aim to investigate whether the effects of glucocorticoids on hepatic health are pregnancy dependent in female rats. Twelve Pregnant and twelve age-matched non-pregnant rats were used for this study; an exogenous administration of glucocorticoid (Dex: 0.2 mg/kg) or vehicle (po) was administered to six pregnant and six non-pregnant rats from gestational day 14 to 19 or for a period of 6 days respectively. Data obtained showed that GC exposure led to a decrease in hepatic glucose-6-phosphate dehydrogenase, glutathione peroxidase, GSH/GSSG ratio and adenosine content in both pregnant and non-pregnant rats. In addition, increased activities of adenosine deaminase and xanthine oxidase, along with increased production of uric acid and increased levels of lactate dehydrogenase, aspartate aminotransferase, alanine transferase, alkaline phosphatase and gamma-glutamyl transferase were observed. In summary, the study indicates that GC-induced liver damage is underlined by depleted hepatic adenosine and glutathione levels as well as elevated markers of tissue inflammation and/or injury. Furthermore, the findings suggest that the effects of GC exposure on hepatic health are pregnancy independent.

Effects of aqueous extract of Hibiscus sabdariffa on renal Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in Wistar rats.

OBJECTIVE: To investigate the effects of oral administration of aqueous extract of Hibiscus sabdariffa on renal Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in rats. METHODS: The 25 and 50 mg/(kg·d) of aqueous extracts of H. sabdariffa were respectively given to rats in the experimental groups for 28 d, and rats in the control group received an appropriate volume of distilled water as vehicle. Na(+)-K(+)-ATPase and Ca(2+)-Mg(2+)-ATPase activities in the kidney were assayed by spectrophotometric method. RESULTS: Administrations of 25 and 50 mg/(kg·d) of aqueous extract of H. sabdariffa significantly decreased the Ca(2+)-Mg(2+)-ATPase activity in the kidney of rats (P<0.05). However, the renal Na(+)-K(+)-ATPase activity of the experimental rats was not affected by either dose of the extract. And the plasma Na(+), K(+) and Ca(2+) levels of the experimental rats had no significant changes. Administration of either dose of the extract did not result in any significant changes in body and kidney weights, the concentrations of plasma albumin and total protein, and alkaline phosphatase, aspartate aminotransferase and alanine aminotransferase activities. However, concentrations of creatinine and urea were significantly reduced by 50 mg/kg of the extract (P<0.05). CONCLUSION: The present study indicates that oral administration of aqueous extract of H. sabdariffa may preserve the renal function despite a decreased renal Ca(2+)-Mg(2+)-ATPase activity.

Relationship of Vitamin A and Thyroid Function in Individuals With Obesity and After Laparoscopic Sleeve Gastrectomy.

Vitamin A deficiency (VAD) occurs in obesity and may be associated with thyroid dysfunction. We aimed to investigate the association of VA with thyroid function in obesity and after laparoscopic sleeve gastrectomy (LSG). Nine hundred and seventy-six obese subjects were enrolled for this study and were divided into VAD, marginal vitamin A deficiency (MVAD), and vitamin A normal (NVA) groups. VAD was defined as VA ≤ 200 ng/ml, MVAD was defined as VA > 200 but <300 ng/ml, and NVA was defined as VA ≥ 300 ng/ml. Thyroid function was compared among groups and the relationship of VA and thyroid function was analyzed. Two hundred and forty-four of the 976 obese subjects underwent LSG, and the change in thyroid function and VA at 3, 6, and 12 months after surgery was measured. Results showed that 37% of all the subjects had subclinical hypothyroidism (SH), and the SH group had lower VA levels than the non-SH group (P = 0.008). Forty-nine percent of all the subjects had MVAD, 9% had VAD, while the MVAD or VAD group had lower FT4 than the NVA group (P = 0.005 and P = 0.001). The VAD group also had higher TSH than NVA group (P = 0.037). VA was significantly negatively associated with TSH (r = -0.151, P = 0.006) and positively associated with FT4 (r = 0.228, P < 0.001). TSH was significantly decreased at 3, 6, and 12 months (3M: from 4.43 ± 2.70 to 2.63 ± 1.46 mU/l, P < 0.001; 6M: from 4.43 ± 2.70 to 3.84 ± 2.34 mU/l, P = 0.041; 12M: from 4.43 ± 2.70 to 2.85 ± 1.68 mU/l, P = 0.024). After LSG surgery, VA levels were slightly increased, when compared to pre-surgery levels, at 3, 6, and 12 months (3M: from 262.57 ± 68.19 to 410.33 ± 76.55 ng/ml, P = 0.065; 6M: from 262.57 ± 68.19 to 281.36 ± 93.23 ng/ml, P = 0.343; 12M: from 262.57 ± 68.19 to 300.37 ± 86.03 ng/ml, P = 0.083). SH group also had lower TSH and higher VA than the non-SH group at 3 months post-surgery [TSH: -1.4(-2.3, -0.3) vs. -0.2(-0.8, -0.2) mU/l, P < 0.001; VA: 163.99 ± 32.58 vs. 121.69 ± 27.59 ng/ml, P = 0.044]. In conclusion VA, which is related to thyroid hormone production, protects against thyroid dysfunction in obese subjects. The improvement of thyroid function in subjects with SH after LSG may be related to the increased VA levels observed post-surgery. Clinical Trial Registration: ClinicalTrial.gov ID: NCT04548232.

Association Between Abdominal Adipose Tissue Distribution and Obstructive Sleep Apnea in Chinese Obese Patients.

Purpose: Factors related to the occurrence of obstructive sleep apnea syndrome (OSAS) in obesity have not been fully clarified. The aim of this study was to identify the association between OSAS and abdominal fat distribution in a cohort of Chinese obese patients. Methods: This cross-sectional study collected demographic data of 122 obese patients who were admitted into the in-patient unit of the Department of Endocrinology, Shanghai Tenth People's Hospital from July 2018 to January 2021. OSAS was diagnosed based on the results of overnight polysomnography, and the abdominal fat distribution was measured by bioelectrical impedance analysis (BIA). Univariate and multivariate logistic regression analyses were used to investigate the association between OSAS and the distribution of abdominal fat. Results: (1) The mean age (SD) of the obese patients included was 32.44 (11.81) years old, and the overall incidence rate of OSAS was 51.06%. Twenty-four (25.53%) patients had mild OSAS, 10 (10.64%) had moderate OSAS, and 14 (14.89%) had severe OSAS. The apnea hypopnea index (AHI) of men was significantly higher than that of women (5.50, interquartile range (IQR) 3.80-30.6 vs. 4.2, IQR 1.4-12 events/h, p = 0.014). Meanwhile, men had a significantly higher visceral fat area when compared with women (180.29 ± 51.64 vs. 143.88 ± 53.42 cm2, p = 0.002). (2) Patients with OSAS had a significantly higher waist circumference, fasting plasma glucose, 2 h postprandial plasma glucose, glycated hemoglobin, and visceral fat area than patients without OSAS (all p < 0.05). (3) AHI was significantly positively associated with BMI, neck circumference, waist circumference, and visceral fat area (r = 0.306, p = 0.003; r = 0.380, p < 0.001; r = 0.328, p = 0.002; r = 0.420, p < 0.001) but not with subcutaneous fat area (p = 0.094). Multivariate analysis demonstrated that abdominal fat area and fasting plasma glucose were independent risk factors for OSAS (odds ratio, 1.016; 95% confidence interval, 1.005-1,026, p = 0.005; odds ratio, 1.618; 95% confidence interval, 1.149-2.278, p = 0.006). Conclusions: In obese patients, the abdominal visceral adipose deposit but not the subcutaneous fat area was associated with OSAS and was an independent risk factor for OSAS. Therefore, improving the distribution of abdominal fat may contribute to alleviating the severity of OSAS in obesity.

Allopurinol and valproic acid improve cardiac triglyceride and Na+-K+-ATPase activity independent of circulating aldosterone in female rats with glucose intolerance.

Context: Studies have shown that cardiac triglyceride accumulation and impaired Na+-K+-ATPase activity are linked to diabetes- related cardiovascular disease, particularly in women.Objectives: We hypothesised that allopurinol (ALL) and valproic acid (VPA) treatment would improve cardiac triglyceride and Na+-K+-ATPase activity independent of circulating aldosterone in Combined Oral Contraceptive (COC)-induced dysglycemiaMaterials and methods: Rats received COC (1.0 µg ethinylestradiol and 5.0 µg levonorgestrel; po) with or without ALL (1 mg; po) and VPA (20 mg; po) for 6 weeks.Results: COC-treatment led to impaired glucose tolerance, accumulated abdominal fat, dyslipidemia, elevated plasma MDA, PAI-1 and aldosterone levels and also reduced plasma nitric oxide bioavailability and cardiac Na+-K+-ATPase activity. However, either ALL or VPA treatment ameliorated these alterations comparably independent of elevated aldosterone levelDiscussion and conclusion: Our results suggest that either ALL or VPA would improve cardiac TG and Na+-K+-ATPase activity comparably in COC-treated rats, regardless of circulating aldosterone level.

Myeloid FoxO1 depletion attenuates hepatic inflammation and prevents nonalcoholic steatohepatitis.

Hepatic inflammation is culpable for the evolution of asymptomatic steatosis to nonalcoholic steatohepatitis (NASH). Hepatic inflammation results from abnormal macrophage activation. We found that FoxO1 links overnutrition to hepatic inflammation by regulating macrophage polarization and activation. FoxO1 was upregulated in hepatic macrophages, correlating with hepatic inflammation, steatosis, and fibrosis in mice and patients with NASH. Myeloid cell conditional FoxO1 knockout skewed macrophage polarization from proinflammatory M1 to the antiinflammatory M2 phenotype, accompanied by a reduction in macrophage infiltration in liver. These effects mitigated overnutrition-induced hepatic inflammation and insulin resistance, contributing to improved hepatic metabolism and increased energy expenditure in myeloid cell FoxO1-knockout mice on a high-fat diet. When fed a NASH-inducing diet, myeloid cell FoxO1-knockout mice were protected from developing NASH, culminating in a reduction in hepatic inflammation, steatosis, and fibrosis. Mechanistically, FoxO1 counteracts Stat6 to skew macrophage polarization from M2 toward the M1 signature to perpetuate hepatic inflammation in NASH. FoxO1 appears to be a pivotal mediator of macrophage activation in response to overnutrition and a therapeutic target for ameliorating hepatic inflammation to stem the disease progression from benign steatosis to NASH.

Hepatoprotective effects of Quassia amara stem bark against cadmium-induced toxicity in male Wistar rats.

OBJECTIVES: The liver is one of the primary biorepositories of cadmium (Cd) and it has been implicated in the pathogenesis of hepatic diseases. Quassia amara stem bark has been reputed to have strong antimalarial, antimicrobial, antiulcerative and amoebicidal properties. This study aims to determine the effects of Q. amara on Cd-induced hepatotoxicity and lipid profile in male Wistar rats. METHODS: The animals were divided into three groups of five animals each. Group 1 served as control while group 2 received Cd (5 mg/kg) for 4 weeks. Prior to Cd treatment, group 3 was treated with Q. amara extract (200 mg/kg) for 2 weeks and received the Q. amara and Cd simultaneously for 4 weeks. RESULTS: Cadmium caused significant increase in serum total cholesterol and low-density lipoprotein (LDL) as well as increased hepatic malondialdehyde (MDA) when compared with the control group. On the other hand, Cd caused a decrease in serum high-density lipoprotein (HDL) and hepatic superoxide dismutase (SOD) when compared with control. However, treatment with Q. amara prevented Cd-induced changes in the lipid profile, augmented Cd-induced decline in SOD and also ameliorated the Cd-induced increase in MDA. Catalase level was however comparable across the groups. CONCLUSIONS: Q. amara ameliorated the Cd-induced damage to liver by preventing dyslipidemia and oxidative damage in the hepatic tissue.

Late gestational testosterone exposure causes glucose deregulation and elevated cardiac VCAM-1 and DPP-4 activity in rats.

CONTEXT: Increased vascular cell adhesion molecule-1 (VCAM-1) has been reported to be a critical link between obesity and atherosclerotic cardiovascular diseases while dipeptidyl peptidase-4 (DPP-4) has been implicated in the development of disrupted glucose regulation and inflammation. OBJECTIVE: This study aimed to investigate the effect of gestational testosterone exposure on glucose metabolism, atherogenic dyslipidemia, as well as circulating and cardiac VCAM-1, oxidative stress biomarkers and DPP-4 activity in pregnant rats. METHODS: Pregnant Wistar rats received either vehicle or testosterone (0.5 mg/kg; sc) between gestational days 14 and 19. RESULTS: Gestational testosterone exposure caused impaired glucose homeostasis that was accompanied with atherogenic dyslipidemia, elevated circulating and cardiac levels of VCAM-1, uric acid, malondialdehyde as well as increased DPP-4 activity. However, nitric oxide levels were decreased. CONCLUSION: This study shows that gestational testosterone exposure causes glucose deregulation and atherogenic dyslipidemia that is accompanied by increased circulating and cardiac VCAM-1 and DPP-4 activity.

Treatment with acetate during late pregnancy protects dams against testosterone-induced renal dysfunction.

Cardiometabolic diseases are complicated by renal damage. Gestational hyperandrogenism causes gestational metabolic dysfunction that is associated with fetal and maternal tissue derangements as well as post-partum maternal androgen excess. Acetate (Ace) conferred hepatoprotection in pregnant rats exposed to excess testosterone (Tes). The effect of excess androgenic exposure on maternal kidney during and after pregnancy is not clear. Therefore, this study investigated the effect of late gestational and post-gestational testosterone exposure on renal functions and plausible renoprotective role of gestational Ace treatment in dams. Thirty pregnant Wistar rats were grouped (n = 10/group) and treated (sc) with olive oil, testosterone propionate (0.5 mg/kg) with or without acetate (200 mg/kg sodium acetate; p.o) between gestational days 14 and 19. Data were obtained from half of the animals on gestational day 20. Data were also obtained from the other half (dams) after treatment of animals which received Tes with or without prior gestational acetate treatment with post-gestational Tes (sc; 0.5 mg/kg) for the last 6 days of an 8-week postpartum period. Biochemical and statistical analyses were performed with appropriate methods and SPSS statistical software respectively. Late gestational excess Tes led to low placental weight (p = 0.0001, F = 205.7), poor fetal outcomes, creatinine (p = 0.0001, F = 385.4), urea (p = 0.0001, F = 300.9) and renal uric acid (UA) (p = 0.0001, F = 123.2), gamma-glutamyl transferase (GGT) (p = 0.004, F = 26.9), malondialdehyde (p = 0.0001, F = 45.96), and lactate dehydrogenase (LDH) (p = 0.0002, F = 150.7). Postpartum Tes exposure also caused elevated plasma testosterone (p = 0001, F = 22.15), creatinine (p = 0.0002, F = 15.2), urea (p = 0.01, F = 13.8) and renal UA (p = 0.0001, 226.8), adenosine deaminase (p = 0001, F = 544.7), GGT (p = 0.0002, F = 401.4) and LDH (p = 0.01, F = 23.7). However, gestational acetate treatment ameliorated the renal effects of gestational and post-gestational Tes exposure. Taken together, gestational acetate would pre-programme dams against renal dysfunction caused by Tes exposure.

Sildenafil augments fetal weight and placental adiponectin in gestational testosterone-induced glucose intolerant rats.

Testosterone induces intra-uterine growth restriction (IUGR) with maternal glucose dysregulation and oxidant release in various tissues. Adiponectin, which modulates the antioxidant nuclear factor erythroid 2-related factor 2 (Nrf2) signaling is expressed in the placenta and affects fetal growth. Sildenafil, a phosphodiesterase type 5 inhibitor (PDE5i), used mainly in erectile dysfunction has been widely studied as a plausible pharmacologic candidate in IUGR. Therefore, the present study sought to determine the effect of PDE5i on placental adiponectin/Nrf2 pathway in gestational testosterone-induced impaired glucose tolerance and fetal growth. Fifteen pregnant Wistar rats were allotted into three groups (n = 5/group) receiving vehicles (Ctr; distilled water and olive oil), testosterone propionate (Tes; 3.0 mg/kg; sc) or combination of testosterone propionate (3.0 mg/kg; sc) and sildenafil (50.0 mg/kg; po) from gestational day 14-19. On gestational day 20, plasma and placenta homogenates were obtained for biochemical analysis as well as fetal biometry. Pregnant rats exposed to testosterone had 4-fold increase in circulating testosterone compared with control (20.9 ± 2.8 vs 5.1 ± 1.7 ng/mL; p < 0.05) whereas placenta testosterone levels were similar in testosterone- and vehicle-treated rats. Exposure to gestational testosterone caused reduction in fetal and placental weights, placental Nrf2 and adiponectin. Moreover, impaired glucose tolerance, elevated plasma triglyceride-glucose (TyG) index, placental triglyceride, total cholesterol, lactate, malondialdehyde and alanine aminotransferase were observed in testosterone-exposed rats. Treatment with sildenafil improved glucose tolerance, plasma TyG index, fetal and placental weights and reversed placental adiponectin in testosterone-exposed pregnant rats without any effect on placental Nrf2. Therefore, in testosterone-exposed rats, sildenafil improves impaired glucose tolerance, poor fetal outcome which is accompanied by augmented placental adiponectin regardless of depressed Nrf2.

Sildenafil ameliorates leptin resistance and normalizes lipid handling in the hypothalamic and adipose tissues of testosterone-exposed pregnant rats.

Leptin and hypothalamic-adipose lipid handling are relevant in determining the shift of metabolic activities. There are scanty findings connecting glucose dysregulation as a result of hyperandrogenism during gestation to hypothalamic-adipose axis and leptin resistance. Sildenafil has recently gained attention in the prevention of intra-uterine growth restriction. The present study aimed at demonstrating the effect of sildenafil on leptin resistance and hypothalamic-adipose lipid handling in testosterone-exposed pregnant rats. Three groups of pregnant Wistar rats (n = 5/group) received olive oil (Ctr, S.C.) or testosterone propionate (Tes, 3.0 mg/kg; sc)or testosterone propionate (3.0 mg/kg; sc) and sildenafil (Tes + PDE5, 50 mg/kg; po)from gestational day 14-19. Blood samples, hypothalamus and adipose tissue were excised for biochemical analysis on day 20. Adipose and body weights, plasma leptin and adiponectin, adipose and hypothalamic leptin and triglyceride, adipose uric acid, hypothalamic Nrf2, catalase and nitric oxide were reduced following gestational testosterone exposure. Also, fasting insulin, plasma triglyceride, uric acid, leptin-adiponectin ratio, hypothalamic free fatty acid, total cholesterol, uric acid, aspartate transaminase and cyclic guanine monophosphate were elevated by testosterone exposure to pregnant animals. Sildenafil ameliorated leptin resistance and normalized hypothalamic-adipose lipid handling. Therefore, sildenafil protects against testosterone-induced leptin resistance and adverse hypothalamic-adipose lipid handling in pregnant rats.

Mineralocorticoid receptor blockade attenuates disrupted glutathione-dependent antioxidant defense and elevated endoglin in the hearts of pregnant rats exposed to testosterone.

Elevated testosterone during late pregnancy has been linked to cardiac dysfunction and poor pregnancy outcomes. The role of mineralocorticoid receptor (MR) in testosterone-induced cardiac dysfunction has not been fully elucidated. The study was therefore designed to investigate the role of MR on gestational excess androgen-induced cardiac disrupted glutathione-dependent antioxidant system and elevated endoglin (Eng) linking it with pregnancy outcomes. Thirty-two pregnant Wistar rats were randomly allotted into four groups (n = 8/group) receiving (sc) olive oil, testosterone propionate (0.5 mg/kg) singly or in combination with non-selective MR blocker (MRB), spironolactone (0.25 mg/kg; po) or selective MRB, and eplerenone (1.0 mg/kg; po) in late between gestational days 14 and 19. The results showed that testosterone exposure resulted in elevated fasting blood glucose, increased cardiac mass, free fatty acid, endoglin, malonaldehyde, oxidized glutathione, uric acid, and lactate production and cardiac injury marker enzymes. On the other hand, testosterone exposure caused reduction in cardiac adenosine, nitric oxide, glutathione, glutathione peroxidase, and glucose-6-phosphate dehydrogenase activities. However, MR blockade by spironolactone and or eplerenone attenuated the effects induced by testosterone exposure. Taken together, the findings from the current study demonstrates that lategestational testosterone induces poor pregnancy outcome that is accompanied by cardiac lipotoxicity,glutathione-dependent antioxidant defense depletion, increased endoglin, lactate and uric acid productionthrough MR activation.

Sodium acetate and androgen receptor blockade improve gestational androgen excess-induced deteriorated glucose homeostasis and antioxidant defenses in rats: roles of adenosine deaminase and xanthine oxidase activities.

Nutritional challenges and androgen excess have been implicated in the development of gestational diabetes and poor fetal outcome, but the mechanisms are not well delineated. The effects of short chain fatty acid (SCFA) on glucose dysmetabolism and poor fetal outcome induced by gestational androgen excess is also not known. We tested the hypothesis that blockade of androgen receptor (AR) and suppression of late gestational androgen excess prevents glucose dysmetabolism and poor fetal outcome through suppression of adenosine deaminase (ADA)/xanthine oxidase (XO) pathway. Twenty-four pregnant Wistar rats were treated (sc) with olive oil, testosterone propionate (0.5 mg/kg) singly or in combination with SCFA (sodium acetate; 200 mg/kg; p.o.) or AR blocker (flutamide; 7.5 mg/kg; p.o.) between gestational days 14 and 19. The results showed that late gestational androgen excess led to glucose deregulation, poor fetal outcome, increased plasma and hepatic free fatty acid and lactate dehydrogenase, liver function marker enzymes, malondialdehyde, uric acid, ADA and XO activities. Conversely, gestational androgen excess resulted in reduced body weight gain, visceral adiposity, plasma and hepatic anti-oxidant defenses (glutathione peroxidase, reduced glutathione/glutathione disulphide ratio, glucose-6-phosphate dehydrogenase, adenosine and nitric oxide). However, all these effects were ameliorated by either sodium acetate or flutamide treatment. The study demonstrates that suppression of testosterone by SCFA or AR blockade protects against glucose deregulation and poor fetal outcome by improvement of anti-oxidant defenses and replenishment of hepatic oxidative capacity through suppression of ADA/XO pathway. Hence, utility of SCFA should be encouraged for prevention of glucose dysmetabolism and poor fetal outcome.

Activation of cardiac renin-angiotensin system and plasminogen activator inhibitor-1 gene expressions in oral contraceptive-induced cardiometabolic disorder.

CONTEXT: Clinical studies have shown that combined oral contraceptive (COC) use is associated with cardiometabolic disturbances. Elevated renin-angiotensin system (RAS) and plasminogen activator inhibitor-1 (PAI-1) have also been implicated in the development of cardiometabolic events. OBJECTIVE: To determine the effect of COC treatment on cardiac RAS and PAI-1 gene expressions, and whether the effect is circulating aldosterone or corticosterone dependent. METHODS: Female rats were treated (p.o.) with olive oil (vehicle) or COC (1.0 µg ethinylestradiol and 10.0 µg norgestrel) daily for six weeks. RESULTS: COC treatment led to increases in blood pressure, HOMA-IR, Ace1 mRNA, Atr1 mRNA, Pai1 mRNA, cardiac PAI-1, plasma PAI-1, C-reactive protein, uric acid, insulin and corticosterone. COC treatment also led to dyslipidemia, decreased glucose tolerance and plasma 17ß-estradiol. CONCLUSION: These results demonstrates that hypertension and insulin resistance induced by COC is associated with increased cardiac RAS and PAI-1 gene expression, which is likely to be through corticosterone-dependent but not aldosterone-dependent mechanism.

Low-dose spironolactone ameliorates insulin resistance and suppresses elevated plasminogen activator inhibitor-1 during gestational testosterone exposure.

CONTEXT: Elevated gestational circulating testosterone has been associated with pathological pregnancies that increase the risk of development of cardiometabolic disorder in later life. OBJECTIVE: We hypothesised that gestational testosterone exposure, in late pregnancy, causes glucose deregulation and atherogenic dyslipidaemia that would be accompanied by high plasminogen activator inhibitor-1 (PAI-1). The study also hypothesise that low-dose spironolactone treatment would ameliorate these effects. METHODS: Pregnant Wistar rats received vehicle, testosterone (0.5 mg/kg; sc), spironolactone (0.5 mg/kg, po) or testosterone and spironolactone daily between gestational days 15 and 19. RESULTS: Gestational testosterone exposure led to increased HOMA-IR, circulating insulin, testosterone, 1-h post-load glucose, atherogenic dyslipidaemia, PLR, PAI-1 and MDA. However, all these effects, except that of circulating testosterone, were ameliorated by spironolactone. CONCLUSIONS: These results demonstrate that low-dose spironolactone ameliorates glucose deregulation and atherogenic dyslipidaemia during elevated gestational testosterone exposure, at least in part, by suppressing elevated PAI-1.

Combined oral contraceptive and nitric oxide synthesis inhibition synergistically causes cardiac hypertrophy and exacerbates insulin resistance in female rats.

Combined oral contraceptive (COC) use or inhibition of nitric oxide (NO) synthesis has been shown to cause hypertension and insulin resistance. However, the concomitant effects of COC and NO deficiency on the heart and glucose regulation are not well known. We therefore hypothesized that COC treatment during NO deficiency would lead to the development of cardiac hypertrophy that is associated with aggravated glucose deregulation, pro-inflammatory and pro-fibrotic biomarkers. Eight-week-old female Wistar rats were randomly allotted into control, NO deficient (NG-nitro-l-arginine methyl ester: L-NAME; 20.0mg/kg b.w.), COC-treated (1.0µg ethinylestradiol+5.0µg levonorgestrel, p.o) and L-NAME+COC-treated groups. The animals were treated daily for 6 weeks. Systolic blood pressure was estimated by tail-cuff plethysmography, insulin resistance (IR) and ß-cell function were estimated by homeostatic model of assessment (HOMA-IR and HOMA-ß). Pro-inflammatory (C-reactive protein; CRP and uric acid) and pro-fibrotic (plasminogen activator inhibitor-1; PAI-1) biomarkers were estimated in the plasma. Cardiac histological examination was also done. Results show that COC or L-NAME treatments led to increased blood pressure, HOMA-IR, impaired ß-cell function, PAI-1, CRP and uric acid, without significant effect on cardiac mass. L-NAME+COC-treated group had significantly higher blood pressure, HOMA-IR, impaired ß-cell function, PAI-1, CRP and cardiac mass than COC- or L-NAME-treated groups. Histological examination validated that COC use during NO deficiency causes cardiac hypertrophy. The present study demonstrates that COC treatment and NO deficiency synergistically causes cardiac hypertrophy that is associated with aggravated glucose deregulation, atherogenic dyslipidemia, pro-inflammatory and pro-fibrotic markers.