Testosterone In Male Rats Research Articles

Subchronic toxicity evaluation of Huobahuagen extract and plasma metabolic profiling analysis combined with conventional pathology methods.

Huobahua, namely, Tripterygium hypoglaucum (Levl.) Hutch, known as a traditional Chinese herbal medicine, especially its underground parts, has been widely developed into several Tripterygium agents for the treatment of rheumatoid arthritis and other autoimmune diseases. It has sparked wide public concern about its safety, such as multi-organ toxicity. However, the toxic characteristics and damage mechanism of Huobahuagen extract (HBHGE) remain unclear. In the present study, subchronic oral toxicity study of HBHGE (10.0g crude drug/kg/day for 12 weeks) was performed in male rats. Hematological, serum biochemical, and histopathological parameters, urinalysis, and plasma metabolic profiling were assessed. The single-dose subchronic toxicity results related to HBHGE exhibited obvious toxicity to the testis and epididymis of male rats. Furthermore, plasma metabolomics analysis suggested that a series of metabolic disorders were induced by oral administration of HBHGE, mainly focusing on amino acid (glutamate, phenylalanine, and tryptophan) metabolisms, pyrimidine metabolism, glutathione metabolism, and steroid hormone biosynthesis. Moreover, it appeared that serum testosterone in male rats treated with HBHGE for 12 weeks, decreased significantly, and was susceptible to the toxic effects of HBHGE. Taken together, conventional pathology and plasma metabolomics for preliminarily exploring subchronic toxicity and underlying mechanism can provide useful information about the reduction of toxic risks from HBHGE and new insights into the development of detoxification preparations.

Gender affirming hormone therapy in the male rat is associated with differential effects on cardiovascular risk factors

Gender-Affirming Hormone Therapy (GAHT) in transgender females (male to female) involves administration of 17ß-estradiol (E2) with an anti-androgen (AA) or castration (CTX). GAHT is used to treat individuals that are born one sex but identify as the other gender. Numerous clinical studies indicate that cardiovascular (CV) risk is elevated in GAHT transgender females. Yet, the mechanisms involved remain unknown. Thus, the purpose of this study was to develop an experimental model of the transgender female and to test the hypothesis GAHT is associated with increased CV risk. Methods: Male Sprague Dawley rats were randomly assigned to the following groups: Control (n=8), E2 [5 mg/day, pellet sc, replaced every 3 weeks, N=6], E2+AA [E2 + Spironolactone, 10 ng/kg/day, diet, N=8], and E2+CTX (N=8). AA and E2 were initiated at 14 weeks of age; CTX rats were exposed to AA for 2 weeks prior to CTX at 16 weeks of age. At 28 weeks of age, EchoMRI for measurement of body weight, fat and lean mass was followed by 24-hour metabolic studies. E2 (ELISA), testosterone (RIA) and analytes (Chemistry Analyzer) were analyzed end of study at 28 weeks of age. Data were analyzed using GraphPad Prism 9 with one-way ANOVA with multi-group comparisons. Statistical significance was set at a P value of <0.05. Results: ( Table 1 ) E2 alone was sufficient to decrease testosterone in male rats. Administration of E2 in the male rat was associated with a significant decrease in body weight, lean mass and average kidney and testes weight. Creatinine was decreased in E2 alone. Yet, BUN was decreased in E2+CTX. E2 + AA was associated with a significant increase in total cholesterol compared to Control; an increase not observed in E2 or E2+CTX. HDL was elevated in E2+AA, whereas LDL-C was decreased in E2, E2+AA and E2+CTX mimicking what is observed in the transfemale population. Collectively, these results demonstrate differential effects of E2+AA versus E2+CTX on CV risk factors in male rats indicating that long-term studies are needed to determine the effect of GAHT on CV risk across the lifespan. [Table: see text] Funding: HL143459, P20-GM-104357, P20-GM121334, T32-HL105324, and LGBTQ Fund of MS This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Goserelin/PLGA solid dispersion used to prepare long-acting microspheres with reduced initial release and reduced fluctuation of drug serum concentration in vivo

To prepare Goserelin (GOS) loaded long-acting microspheres with reduced initial release and prolonged drug release time of GOS, GOS/PLGA solid dispersion (by hot-melt extrusion, HME) was dissolved/dispersed in dichloromethane (DCM) to prepare microspheres by O/W method. From results of molecular dynamics simulation, PLGA and GOS molecules completely and uniformly dissolved and dispersed in DCM, respectively. In F5 microspheres (prepared by HME-O/W method), GOS existed as molecular or amorphous state, but not aggregation. Burst release of F5 microspheres (2.75%) was similar with Zoladex™ implant (0.39%) and less than F10 microspheres (prepared by S/O/W method, 25.92%). After lag phase, GOS released rapidly from F5 microspheres and the cumulative release on the 45th days was 95.14%. After injection of F5 microspheres, GOS serum concentration was relative steady at the range of 27.64–175.27 ng/mL for nearly 35 days. AUC(0-35 day) of F5 microspheres was almost 2 times that of F10 microspheres. Pharmacodynamics study also showed potential effect of F5 microspheres on inhibiting the secretion of testosterone in male rats. HME-O/W method is potential to establish long-acting PLGA microspheres (loading water-soluble drug), exhibiting stable drug serum concentration in vivo, and without large concentration fluctuation or serious pain/side effects.

The Effect of Saffron (<i>Crocus sativus L. Iridaceae</i>) Orally Administration on Blood Level of Sex Hormones in Rats

Modern medicine is currently marked by an increased interest in herbal pharmaceutical drugs traditionally applied in folk medicine in a significant number of diseases. In this regard, saffron (<i>Crocus sativus L. Iridaceae</i>) is of particular importance. This paper presents the results of study of the effects of Azerbaijan-grown saffron on blood level of follicle-stimulating hormone (FSH) in female rats, as well as on blood level of testosterone in male rats. In the blood serums of animals, using hormonal test systems for enzyme immunoassay, FSH and testosterone levels were determined. The findings revealed a decrease in blood levels of FSH in 12-month-old female rats as compared to the control group (comprising animals of the same age which did not receive the saffron extract), as they approximated the registered levels of 6-month-old female rats. Saffron increased the blood level of testosterone as compared to untreated controls, which did not receive saffron. Saffron’s unique medicinal properties largely owe to the diversity of biologically active substances it contains The effects of saffron treatment observed in the course of this study could be explained by the direct impact of saffron and its components on the sex glands and the central nervous system. Findings of diverse pharmacological effects of the saffron extract open new horizons for the development of scientifically corroborated recommendations for application in practical medicine.

Ninety-day oral toxicological profiling of Kolaviron (an extract of Garcinia kola) in male and female rats

There remains an insufficiency of data on the long-term toxicological profile of Garcinia kola Heckel and its extract, Kolaviron (KV), despite several studies on its pharmacological effects. This research was designed to investigate the long-term histopathological, hematological, biochemical, hormonal, reproductive, and oxidative effects of 90 days administration of KV to male and female rats, as well as additional 30 days reversibility study to assess the potential for reversal of induced effects. Fifty-six male and female Wistar rats divided into four groups were treated orally with distilled water/propylene glycol, 20 mg/kg KV, 100 mg/kg KV, and 500 mg/kg KV for 90 days. At the end of 90 days and 30 additional days of reversibility study, 5 ml blood was collected from animals for relevant analyses. Vital organs were harvested for histopathological assessments. In this study, KV did not elicit any adverse effect on histopathological presentations of vital organs which were generally non-abnormal. There was significant increase (p < 0.05) in LEU, MON, EOS%, BAS%, HCT (male animals) and LYM%, EOS%, BAS%, RBC, hemoglobin and MCH (female animals). There was significant diminution (p < 0.05) in cholesterol, triglycerides, LDL, and VLDL levels, with significant increase (p < 0.05) in HDL level in both male and female animals. KV elicited a non-significant increase in sperm count accompanied by a significant increase (p < 0.05) in levels of Follicle stimulating hormone (FSH) and testosterone in male rats. Furthermore, KV elicited significant (p < 0.001–0.05) elevation in the levels of GSH, SOD and CAT, and diminution in the level of MDA. The findings in this study suggest that long-term administration of KV is considerably safe with some variations in response between male and female animals. The possible sustenance of observed effects after cessation of KV administration, lipid lowering, erythropoiesis inducing, and immune system boosting activities of KV were confirmed in this study.

Effects of co- exposure to heat and psychological stresses on serum levels of testosterone in male rats

Effects of co- exposure to heat and psychological stresses on serum levels of testosterone in male rats

Conditioned place preference of kisspeptin-10

INTRODUCTION: Kisspeptins (KISS), a group of brain neuropeptides are involved in sexual behavior. KISS activate the hypothalamic neurons that synthesize gonadotropin releasing hormone. KISS was also detected in the limbic system. Earlier, we showed the activation of sexual motivation after the administration of kisspeptin-10 without increasing the level of testosterone in male rats, which suggests the extrahypothalamic effect of KISS.&#x0D; The aim of this work was to study the possibility of aquisition of conditioned place preference of kisspeptin-10, as well as to study the emotional and investigational behavior in rats after intranasal peptide administration.&#x0D; METHODS: Conditioned place preference test (CPP), open field test (OP) and elevated plus maze (EPM) were used in male Wistar rats.&#x0D; RESULTS: When studying CPP, animals spent 78.6 6.3% of the time in the chamber associated with the administration of KISS compared to control animals with administration of physiological saline (51.2% of the experiment time; p 0.05). After kisspeptin-10 administration locomotor activity was 2-fold increased (p 0.05), and the number of sniffings was 2-fold increased too (p 0.05). The parameters did not significantly differ in animals treated with kisspeptin or saline in PCL.&#x0D; CONCLUSION: Thus repeated intranasal administration of kisspeptin-10 induces the aquisition of CPP in rats. This suggests that kisspeptin-10 can cause activity in the reward system or the activation of brain regions associated with this system, which ultimately leads to the formation of an emotionally positive state.

Sex Differences in Macrophage Polarization During the Early Progression of Renal Disease in Obese Dahl Salt‐Sensitive Rats Prior to Puberty

Childhood/prepubertal (PPO) obesity has emerged as an epidemic and major health problem over the last few decades and is a risk factor for the development of proteinuria. Recently, we reported that the development of progressive renal injury in obese female and male Dahl salt-sensitive leptin receptor mutant (SSLepRmutant) rats was associated with increased renal macrophage infiltration as early as 8 weeks of age. The current study investigated whether there are differences in the polarization of infiltrating macrophages in female and male SSLepRmutant rats during the early progression of renal injury (M1; pro-inflammatory and M2; anti-inflammatory). Sex hormones were also monitored to determine if the development of renal injury in SSLepRmutant strain occurs prior to puberty. Female and male lean SS and obese SSLepRmutant rats were studied biweekly from 4 to 10 weeks of age monitoring serum sex hormones and renal injury. Estradiol and testosterone levels were similar in all groups at 4 weeks of age and averaged 11±1 and 0.44±0.15 ng/mL, respectively. The levels of estradiol only significantly increased in female SS rats at 10 weeks of age (24±7 ng/mL; p<0.05 vs 4 weeks of age) and remain unchanged in all other groups. When examining the levels of testosterone in male rats, we observed a marked increase in male SS rats only at 10 weeks of age (2.53±0.69 ng/mL; p<0.05 vs 4 weeks of age), and we did not detect any differences from baseline in the other groups. Proteinuria was significantly higher in female and male SSLepRmutant rats as opposed to the values observed in SS rats at 4 weeks of age (56±7 and 60±13 vs 12±4 and 9±3 mg/day, respectively, n=6). While we observed minimal increases in proteinuria in SS rats at 8 weeks of age, proteinuria increased to 288±45 and 376±44 mg/day in female and male SSLepRmutant rats, respectively. We observed no sex differences in proteinuria in either the SSLepRmutant or SS rats. In support of our previous work, renal macrophage (CD68+) infiltration was significantly higher in the SSLepRmutant rats when compared to their lean counterparts. Interestingly, the female SSLepRmutant rats displayed significantly higher macrophage (CD68+) infiltration than their male counterparts. Moreover, female SSLepRmutant rats displayed significant increases in both macrophage subtypes M1 (CD68+/iNOS+) and M2 (CD68+/CD163+) versus male SSLepRmutant rats as well as SS rats. The male SSLepRmutant rats only displayed significant increases in M1 macrophages (CD68+/iNOS+) compared to male SS rats. The kidneys from the SSLepRmutant rats displayed significant glomerular injury and marked renal fibrosis versus the values measured in SS rats without any sex differences. These data indicate that the SSLepRmutant strain displays sex differences in renal macrophage polarization and develops renal injury prior to the onset of puberty. The SSLepRmutant strain may be considered a useful model to study the early development of renal injury associated with PPO and to understand the underlying mechanisms that contribute to future risk of obesity-related CKD.

Combined Effects of Intermittent Hypoxia and Exercise on the Production of Testosterone in Male Rats

Combined Effects of Intermittent Hypoxia and Exercise on the Production of Testosterone in Male Rats

Bisphenol a Hormonal Disrupture and Preventive Effect of Rose Water and Clove Oil

Bisphenol A (BPA) which considered synthetic estrogen that is an essential component of many plastic industries. This research was done to see the impacts of exposure of BPA on reproductive organs and hormonal levels in male and female albino Sprague-Dawley rats. The protective effect of rose water and clove oil on BPA was investigated. Ninety rats were divided into 18 groups, 9 groups of males and they are like for females. Rats were exposed to different oral gavage route 3 times a week by doses of BPA (20 µg, 20 mg, 200 mg) /kg b.wt for 6 weeks and BPA was solubilized in corn oil. BPA induced a significant decrease in total and free testosterone in male rats, in contrast to a significant increase in thyroid-stimulating hormone (TSH), progesterone, estrogen (E2), and prolactin (PRL), while a decrease in Follicle-stimulating hormone (FSH) compared to control groups. Histopathological examination revealed that rosewater and clove oil reduced testes and ovary damages induced by BPA. Rosewater and clove oil components were scanned using GC/MS, which showed that rosewater and clove oil contains phenols, flavonoids, and these inevitably confirm that a prominent role in preventing the damage during treatment. Results indicated that the used doses of BPA disrupted the sex hormone levels in both male and female rats caused reproductive impaired. The chemical and histopathological analysis results indicated that clove oil and rose water improved the adverse effect of BPA. Rosewater and clove oil improved the changes which were stimulated by BPA.

Effects of bone marrow mesenchymal stem cells on ovarian and testicular function in aging Sprague-Dawley rats induced by D-galactose

ABSTRACT To investigate the effect of bone marrow mesenchymal stem cells (MSCs) on ovarian and testicular function of aging Sprague-Dawley (SD) rats induced by D-galactose (D-gal) and try to clarify the underlying functional mechanism. Adherent culture was used to isolate and purify rat MSCs. The status, proliferation and differentiation of MSCs were detected by hematoxylin-eosin staining, MTT, colony formation, flow cytometry and directional differentiation. The aging rat model was established by subcutaneous injection of D-gal, and the homing of MSCs was detected by fluorescence microscope after infusion of GFP-labeled MSCs through caudal vein. ELISA was used to detect the content of sex hormone in serum, and HE staining was used to observe the structure and morphology of testis and ovary. The isolated and purified MSCs were in good condition, and most of the cells were in G1 phase, which had strong abilities of cell proliferation, colony formation and differentiation. After GFP-labeled MSCs were infused, MSCs could be homed into the testis and ovary of rats. MSCs infusion could significantly improve the morphology of testis and ovary, increase the contents of P and E2 while decrease the contents of LH and FSH in female rats, and increase the content of testosterone in male rats (P < 0.01). It also increased the activity of superoxide dismutase (SOD) in serum of ovary and testis and significantly decreased the content of malondialdehyde (MDA). MSCs affected the content of MDA and the activity of SOD by reducing the expression of cyclin-dependent kinase inhibitor 2A (p16) and increasing proliferating cell nuclear antigen (PCNA), consequently improving the aging and injury of reproductive organs.

Age and Gender-Related Changes in Renal Haemodynamics of Albino Rats: The Possible Role of Cytokines and Prostaglandins

AbstractBackground: The normal aging process leads to changes in kidney morphology, hemodynamics and function, which are influenced by several factors, including gender. Females develop less age-dependent loss of renal function due to cardiorenal protective effects of estrogens.Aim of Study: The aim of this study was to elucidate the age and gender-related changes in some renal haemodynamics in albino rats with special focusing on the role of cytokines and prostaglandins in establishment of such changes.Material and Methods: Sixty albino rats (30 males & 30 females) of local strain were divided into 2 major groups (Group I of male rats and Group II of female rats) was further subdivided into 3 subgroups: Young (4wk), young adult (3mo) and old (25mo). Body Weight (BW) and absolute Kidney Weight (KW) were measured. The Systolic Blood Pressure (SBP) of the rats was measured by the rat-tail plethysmography technique using a tail-cuff sphygmomanometer. The Renal Blood Flow Velocity (RBFV) and Renal Vascular Resistance (RVR) were measured using bi-directional blood flow meter with FFT-analysis. The blood samples were collected after a period of overnight fasting, left to be clotted, centrifuged and serum was separated for measurement of serum testosterone in male rats, serum estrogen in female rats, creatinine clearance, serum IL1beta, IL6 and serum PGE.Results: The aging of male rat group is accompanied by change in the renal hemodynamic and some blood measure-ments. This is represented by significant increase in systolic blood pressure, renal vascular resistance, serum PGE, serum interleukin1-b & 6, impaired renal function and significant decrease of renal blood flow. It was observed that the old female group had decreased in estrogen hormone level, which led to increase in systolic blood pressure, renal vascular resistance, serum PGE, serum interleukin1-b & 6 and signif-icant decrease renal blood flow.Conclusion: Aging has a significant influence in renal hemodynamic (decrease of renal blood flow and increase of renal vascular resistance) and also, serum interleukin1-b & 6 have a role in this change accompanied with pathophysiology of aging. Female is more protected from complications of the kidney aging than male due to the previous effect of estrogen hormone.

Investigate the relation between Baicalin effect and Gene expression of LH, FSH, Testosterone in male rats treated with Gemcitabine drug

Background: Baicalin is a flavonoid that is extracted from the Chinese herbal plant, which is a member of the mint group, which is known as the (Scutellaria baicalensis, golden root, Skullcap). Baicalin is one of the best and most powerful antioxidants found in nature, it is used to treat many diseases and is characterized by no side effects. Methods: The current study was conducted from January to June 2018. In the University of Al-Qadisiyah / Faculty of Veterinary Medicine / Animal House. In the study, 80 males of white rats were used in this study at the age of 10-12 weeks at a mean weight of 175 grams. The animals were randomly distributed to eight groups. The control group (C) is pumped with distilled D.W water only. The treatment group (T1, T2) was injected with Gemcitabine with a concentration of 15 mg / kg bw for 30 and 60 days respectively. The treatment group (T4, T3) was extracted with Baicalin extract at a concentration of 30 mg / kg bw for 30 and 60 days. The treatment group (T5) was injected with Gemcitabine with a concentration of 15 mg / kg bw and a Baicalin extract at a concentration of 30 mg / kg bw simultaneously for 60 days. The treatment group (T6) was injected with Gemcitabine at a concentration of 15 mg / kg bw for 30 days and then injected with Baicalin extract at a concentration of 30 mg / kg bw for the end of the experiment. The treatment group (T7) was injected with the Baicalin extract at a concentration of 30 mg / kg body weight for 30 days and then injected with Gemcitabine at a concentration of 15 mg / kg body weight for the end of the experiment. The present study aimed to identify and evaluate the protective role of the Baicalin extract in reducing the toxicity of Gemcitabine to the body and reproductive organs, as well as the genetic expression of genes responsible for fertility hormones. Results: The results of the study showed a significant reduction (P <0.05) in the level of gene expression of (Testosterone, LH, FSH) when treated with Gemcitabine with a concentration of 15 mg / kg body weight in the treatment groups (T1, T2). Also, the results of the study showed significant significant improvement (P <0.05) in the study groups (T3, T4), which were given Baicalin extract at 30 mg / kg body weight for 30 and 60 days respectively, when compared to the treatment groups (T1, T2) which given Gemcitabine. And the treatment group (T5) given Gemcitabine and Baicalin extract as the for 60 days showed combination showed significant improvement compared with T1 and T2, and to a lesser extent (T7, T6). Conclusion: Baicalin is a anti-oxidant flavonide has a significant role in removing the toxicity caused by Gemcitabine drug and improving fertility by improving its gene expression.

Effect of Summer Savory (Satureja Hortensis L.) on the Concentration of Gonadotropins and Testosterone in Male Rats Exposed to Chronic Immobilization Stress

Effect of Summer Savory (Satureja Hortensis L.) on the Concentration of Gonadotropins and Testosterone in Male Rats Exposed to Chronic Immobilization Stress

12-week treadmill exercise program elicits lower energy availability without changes in serum testosterone in male rats

The purpose of this study was to investigate whether a treadmill endurance exercise program would reduce serum testosterone and leptin in male rats and assess the impact of increased dietary cholesterol on serum hormones. Male Sprague-Dawley Rats (n = 20) were randomly assigned to a control group (C) or an exercise training group (EX) that performed treadmill running 40 min/day, 6 days/week for 12 weeks. At study midpoint (week 6), rats were randomized to a high-cholesterol (HC) diet (n = 10) or remain on standard semi-purified (LC) diet (n = 10). Results are presented as median [IQR]. At end of week 6, EX + LC had significantly lower body weight (508 [460–527] vs 570 [516–606] g; p = 0.01), mean daily energy intake (76.3 [74.9–82.2] vs 90.9 [86.9–94.5] kcal; p < 0.01), and serum leptin (0.4 [0.3–0.6] vs 3.3 [2.0–4.0] ng/mL; p < 0.01) in comparison to C + LC. No difference was observed between EX + LC and C + LC in serum testosterone (12.6 [6.9–18.3] vs 11.7 [7.6–18.9] ng/mL). At end of week 12, EX + LC had significantly lower body weight (514 [483–568] g) compared to C + LC (644 [575–680] g; p < 0.01) and C + HC (650 [583–702] g; p < 0.01). Serum Leptin in both EX + LC (0.6 [0.2–0.8] ng/mL) and EX + HC (0.6 [0.3–1.6] ng/mL) was significantly lower than C + LC (3.0 [2.2–4.2] ng/mL; p < 0.01). No significant difference in testosterone was observed between C + LC and C + HC (4.3 [3.3–8.3] vs 6.3 [3.2–9.3] ng/mL, respectively). Despite lower energy availability, exercise-induced changes in sex hormones may not occur in training programs ≤ 12 weeks. Lower voluntary energy intake observed in exercise groups despite greater energy expenditure may indicate that lower energy availability in endurance-trained individuals may be inadvertent.

Erratum to: Gonadotropin-releasing hormone, kisspeptin, and gonadal steroids directly modulate nucleobindin-2/nesfatin-1 in murine hypothalamic gonadotropin-releasing hormone neurons and gonadotropes.

Neuroendocrine regulation of metabolism and reproduction are tightly interlinked. Nesfatin-1 is an 82 amino acid metabolic peptide derived from nucleobindin-2 (NUCB2). NUCB2 mRNA and protein significantly increase in the hypothalamus of rats during puberty-to-adult transition. Administration of nesfatin-1 modulates circulating LH and testosterone in male rats. However, whether nesfatin-1 acts directly on neurons and gonadotropes remain unknown. In addition, whether reproductive hormones of the hypothalamo-pituitary gonadal axis modulate NUCB2/nesfatin-1 is unclear. To address these, we employed murine hypothalamic (GT1-7) and pituitary (LβT2) cells in vitro. Nucb2 expression, and NUCB2/nesfatin-1 immunoreactivity were observed in both GT1-7 and LβT2 cells, and in the hypothalamus of mice. Nesfatin-1 co-localized GnRH in GT1-7 cells, and in the hypothalamic perikarya of mice. Cells were treated with kisspeptin, GnRH, and estradiol and testosterone, as well as nesfatin-1 for 2, 6 or 24 hours. Synthetic nesfatin-1 increased Kiss1r and Gnrh expression in GT1-7 cells and Lhβ in LβT2. Nesfatin-1 increased GnRH and LHβ protein expression in GT1-7 and LβT2 at 6-hour post incubation respectively. Both NUCB2 mRNA and protein were increased in GT1-7 cells treated with kisspeptin. Testosterone increased NUCB2 mRNA and protein expression in GT1-7 and LβT2. 17β-estradiol increased NUCB2 mRNA and protein expression in LβT2. Nesfatin-1 acts directly on hypothalamic neurons and gonadotropes to elicit a generally positive influence on the endocrine milieu regulating reproduction in mice. Reproductive hormones, in turn, modulate brain and pituitary NUCB2/nesfatin-1. In conclusion, we provide additional information to designate nesfatin-1 as a novel, additional factor that helps reproductive success.

12-Week Treadmill Program Elicits Low Energy Availability Without Changes in Serum Testosterone in Male Rats

Male endurance athletes have been reported to have lower testosterone concentrations than their sedentary counterparts, which may have detrimental health effects including increased risk of musculoskeletal injury and fertility complications secondary to decreased sex hormone production. Cholesterol supplementation has been reported to increase serum sex hormones. PURPOSE: The purpose of this study was to investigate whether a treadmill endurance exercise program would cause exercise-induced reproductive dysfunction in male rats and assess the impact of increased dietary cholesterol on sex hormone levels. METHODS: Male Sprague-Dawley Rats (n=20) were randomly assigned to a control group (C) or an exercise training group (EX) that performed treadmill running 40 min/day, 6 days/wk for a duration of 12 wks. At study midpoint (wk 6), rats were randomized to receive either a High-Cholesterol (HC) Diet (n=10) or remain on standard purified diet (n=10). Fasting blood samples were collected at baseline, wk 6, and wk 12. Serum testosterone (T) and leptin were measured via ELISA. Serum lipids (TC, HDL, LDL, TG) were measured via clinical chemistry analyzer. Body weight (BW) and voluntary food intake (EI) were measured weekly. RESULTS: At end of wk 6, EX had significantly lower BW (494.3+34.7g versus 565.3+47.9g, p=0.001), mean daily EI (77.5+3.5 kcal versus 91.6+5.2 kcal, p<0.001), and serum leptin (90.8+40.1 pg/mL versus 635.7+225.6 pg/mL, p=0.001) in comparison to C. No difference was observed between EX and C in serum T (12.7+6.0 ng/mL versus 12.9+5.8 ng/mL). At end of wk 12, exercise groups (EX and EX+HC) had significantly lower BW (539.4+40.6g versus 645.1+60.7g, p<0.001), mean daily EI (81.7+2.9 kcal versus 87.8+1.9 kcal, p<0.01), and serum leptin (132.8+110.1 pg/mL versus 519.2+300.8 pg/mL, p=0.001) in comparison to C and C+HC. HC diet did not have significant impact upon serum T in comparison to standard diet (3.8+3.4 ng/mL versus 4.9+2.4 ng/mL). CONCLUSIONS: Despite low energy availability, exercise-induced reproductive changes may not occur in training programs <12 weeks. Lower EI observed in exercise groups despite higher energy expenditure may indicate that low energy availability in endurance-trained individuals may be inadvertent. Supported by American Egg Board Graduate Fellowship Research Grant

The Effect of Luteinizing Hormone Reducing Agent on Anxiety and Novel Object Recognition Memory in Gonadectomized Rats.

Introduction:Mood disorders such as anxiety and depression are common following menopause and andropause. Lack of sex steroid hormones is suggested as the primary cause of these disturbances. The level of luteinizing hormone (LH) would also rise 3–4 times than normal in these people. The potential effects of LH on mood and cognitive symptoms following menopause and andropause are still unknown. This study aimed to investigate the effect of increased LH on novel object discrimination (NOD) memory and anxiety like behavior in gonadectomized rats.Methods:Four-month-old male and female Wistar rats were randomly assigned into 4 groups (in each sex): control rats (Cont), gonadectomized without treatment (GnX), gonadectomized treated with triptorelin, a GnRH agonist which reduces LH release eventually, (GnX+Tr), gonadectomized treated with triptorelin plus sex steroid hormone, estradiol in female and testosterone in male rats (GnX+Tr+S/T). After 4 weeks treatment, anxiety score (elevated plus maze) and NOD were measured. Data were analyzed using One-way ANOVA, and P-values less than 0.05 were considered as significant.Results:Gonadectomy increased anxiety like behaviors (decrease of presence time in the open arms) in female rats (P=0.012), but not in male ones (P=0.662). Additionally, triptorelin alone reduced the increased anxiety score in gonadectomized female rats, compared to group treated with both triptorelin and estradiol. Furthermore, it was shown that gonadectomy and or treatment with triptorelin and sex steroids had no significant effect on novel object recognition memory in both female (P=0.472) and male rats (P=0.798).Conclusion:Findings of this study revealed that increased level of LH following menopause or andropause should be considered as a possible cause for increased anxiety. Also, this study showed that LH reducing agents would reduce anxiety like behavior in gonadectomized female rats. The effect of increased LH on cognitive functions such as novel object recognition memory was not evident in this study and needs further studies.

Gonadotropin-releasing hormone, kisspeptin, and gonadal steroids directly modulate nucleobindin-2/nesfatin-1 in murine hypothalamic gonadotropin-releasing hormone neurons and gonadotropes.

Neuroendocrine regulation of metabolism and reproduction are tightly interlinked. Nesfatin-1 is an 82 amino acid metabolic peptide derived from nucleobindin-2 (NUCB2). NUCB2 mRNA and protein significantly increase in the hypothalamus of rats during puberty-to-adult transition. Administration of nesfatin-1 modulates circulating LH and testosterone in male rats. However, whether nesfatin-1 acts directly on neurons and gonadotropes remain unknown. In addition, whether reproductive hormones of the hypothalamo-pituitary gonadal axis modulate NUCB2/nesfatin-1 is unclear. To address these, we employed murine hypothalamic (GT1-7) and pituitary (LβT2) cells in vitro. Nucb2 expression, and NUCB2/nesfatin-1 immunoreactivity were observed in both GT1-7 and LβT2 cells, and in the hypothalamus of mice. Nesfatin-1 co-localized GnRH in GT1-7 cells, and in the hypothalamic perikarya of mice. Cells were treated with kisspeptin, GnRH, and estradiol and testosterone, as well as nesfatin-1 for 2, 6 or 24 hours. Synthetic nesfatin-1 increased Kiss1r and Gnrh expression in GT1-7 cells and Lhβ in LβT2. Nesfatin-1 increased GnRH and LHβ protein expression in GT1-7 and LβT2 at 6-hour post incubation respectively. Both NUCB2 mRNA and protein were increased in GT1-7 cells treated with kisspeptin. Testosterone increased NUCB2 mRNA and protein expression in GT1-7 and LβT2. 17β-estradiol increased NUCB2 mRNA and protein expression in LβT2. Nesfatin-1 acts directly on hypothalamic neurons and gonadotropes to elicit a generally positive influence on the endocrine milieu regulating reproduction in mice. Reproductive hormones, in turn, modulate brain and pituitary NUCB2/nesfatin-1. In conclusion, we provide additional information to designate nesfatin-1 as a novel, additional factor that helps reproductive success.

Coactivation of μ- and κ-Opioid Receptors May Mediate the Protective Effect of Testosterone on the Development of Temporomandibular Joint Nociception in Male Rats.

To investigate whether the protective effect of testosterone on the development of temporomandibular joint (TMJ) nociception in male rats is mediated by the activation of central opioid mechanisms. Experiments were performed on 156 male Wistar rats. A pharmacologic approach was used to assess the ability of opioid receptor antagonists infused into the dorsal portion of the brainstem and adjacent to the caudal component (subnucleus caudalis) of the spinal trigeminal nucleus to block the protective effect of testosterone in male rats. The TMJ injection of 0.5% formalin was used as a nociceptive stimulus. One-way or two-way ANOVA was used for data analyses. The injection of 0.5% formalin into the TMJ induced a significant nociceptive behavior in gonadectomized male rats (P < .05), but not in naïve, sham, and testosterone-replaced gonadectomized rats, confirming that testosterone prevents the development of TMJ nociception. The injection of either the nonselective opioid receptor antagonist naloxone (15 μg) or the simultaneous injection of the μ-opioid receptor antagonist Cys2, Tyr3, Orn5, Pen7amide (CTOP, 30 μg) and the κ-opioid receptor antagonist Nor-Binaltorphimine (Nor-BNI, 90 μg) significantly increased the 0.5% formalin-induced behavioral response in sham and testosterone-replaced gonadectomized rats (P < .05) but had no effect in gonadectomized rats. However, the injection of each selective opioid receptor antagonist alone or the simultaneous injection of μ- or κ- and δ-opioid receptor antagonists had no effect. These findings indicate that the protective effect of endogenous testosterone on the development of TMJ nociception in male rats is mediated by the activation of central opioid mechanisms. Furthermore, the coactivation of central μ- and κ-opioid receptors is necessary for testosterone to protect male rats from developing TMJ nociception.