32 resultados para SERUM TESTOSTERONE

em Biblioteca Digital da Produção Intelectual da Universidade de São Paulo


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Aims: Inflammation may have an important role in the beginning and in the progress of cardiovascular diseases. Testosterone exerts important effects on vascular function, which is altered in arterial hypertension. Thus, the aim of this study was to evaluate the influence of endogenous testosterone on leukocyte behavior in post-capillary venules of the mesenteric bed of spontaneously hypertensive rats (SHR). Main methods: 18 week-old intact SHR, castrated SHR and normotensive rats (intact Wistar) were used. Blood pressure was measured by tail plethysmography and serum testosterone levels by ELISA. Leukocyte rolling, adhesion and migration were evaluated in vivo in situ by intravital microscopy. Key findings: Castration significantly reduced blood pressure and reversed the increased leukocyte rolling and adhesion observed in SHRs. Leukocyte counts and other hemodynamic parameters did not differ among groups. SHRs displayed increased protein expression of P-selectin and ICAM-1 in mesenteric venules when compared to intact Wistar. Castration of SHRs restored the protein expression of the cell adhesion molecules. Significance: The findings of the present study demonstrate the critical role of endogenous testosterone mediating the effects of hypertension increasing leukocyte-endothelial cell interaction. Increased expression of cell adhesion molecules contribute to the effects of endogenous testosterone promoting increased leukocyte rolling and adhesion in SHRs. (c) 2012 Elsevier Inc. All rights reserved.

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This study investigated the effects of perinatal cadmium exposure on sexual behavior, organ weight, and testosterone levels in adult rats. We examined whether immediate postpartum testosterone administration is able to reverse the toxic effects of the metal. Forty pregnant Wistar rats were divided into three groups: 1) control, 2) 10 mg kg-1 cadmium chloride per day, and 3) 20 mg kg-1 cadmium chloride per day. These dams were treated on gestational days 18 and 21 and from lactation 1 to 7. Immediately after birth, half of the offspring from the experimental and control groups received 50 μl (i.p.) of 0.2% testosterone. Male sexual behavior, histological analysis and weight of organs as well as serum testosterone levels were assessed. Results showed that both cadmium doses disrupted sexual behavior in male rats, and postnatal treatment with testosterone reversed the toxic effects of 10 mg kg-1 cadmium and attenuated the effects of 20 mg kg-1 cadmium. Body weight and absolute testis, epididymis, and seminal vesicle weight were decreased by the higher cadmium dose, and testosterone supplementation did not reverse these effects. Serum testosterone levels were unaffected by both cadmium doses. No histological changes were detected in all organs analyzed. Maternal cadmium exposure effects in sexual parameters of male rat offspring were explained by the altered masculinization of the hypothalamus. We suggest that cadmium damaged cerebral sexual differentiation by its actions as an endocrine disruptor and supported by the changes discretely observed from early life during sexual development to adult life, reflected by sexual behavior. Testosterone supplementation after birth reversed some crucial parameters directly related to sexual behavior.

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Sexual differentiation in the brain takes place from late gestation to the early postnatal days. This is dependent on the conversion of circulating testosterone into estradiol by the enzyme aromatase. The glyphosate was shown to alter aromatase activity and decrease serum testosterone concentrations. Thus, the aim of this study was to investigate the effect of gestational maternal glyphosate exposure (50 mg/kg, NOAEL for reproductive toxicity) on the reproductive development of male offspring. Sixty-day-old male rat offspring were evaluated for sexual behavior and partner preference; serum testosterone concentrations, estradiol, FSH and LH; the mRNA and protein content of LH and FSH; sperm production and the morphology of the seminiferous epithelium; and the weight of the testes, epididymis and seminal vesicles. The growth, the weight and age at puberty of the animals were also recorded to evaluate the effect of the treatment. The most important findings were increases in sexual partner preference scores and the latency time to the first mount; testosterone and estradiol serum concentrations; the mRNA expression and protein content in the pituitary gland and the serum concentration of LH; sperm production and reserves; and the height of the germinal epithelium of seminiferous tubules. We also observed an early onset of puberty but no effect on the body growth in these animals. These results suggest that maternal exposure to glyphosate disturbed the masculinization process and promoted behavioral changes and histological and endocrine problems in reproductive parameters. These changes associated with the hypersecretion of androgens increased gonadal activity and sperm production.

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Methylmercury (MeHg) is an environmental pollutant that is highly toxic to the central nervous system. As its effects on male reproductive system are poorly understood, this study was carried out to analyse the effects of MeHg on the rat prostate. To evaluate the MeHg toxicity on ventral prostate, three groups of adult male Wistar rats received oral doses of 0.5, 1.0 and 3.0mg/kg MeHg, respectively, on a daily basis for 14days. A fourth group was used as a control. The prostate weight was decreased in rats treated orally with 0.5mg/kg MeHg compared to controls. Also, Hg concentration increased significantly in the prostate after treatments. There were reductions in serum testosterone levels and androgen receptor immunoreactivity in animals receiving 3.0mgMeHg/kg. The stereological data showed changes in the prostatic epithelial, stromal and luminal compartments which varied according to the different doses. Histopathological alterations, such as chronic inflammation, stratified epithelial hyperplasia and epithelial inflammatory reactive atypia, were observed in the 0.5mg/kg MeHg-treated group. Epithelial atrophy was observed in the 3.0mg/kg MeHg-treated group. In conclusion, the MeHg affects prostatic homoeostasis resulting in histopathological changes that may be relevant in the pathogenesis of prostatic disease.

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Cyclosporin A (CsA) is an immunosuppressive drug widely used in medicine to reduce the immune system activity and, therefore, the risk of organ rejection after transplantation. However, many side effects can be related to its use, such as, reduction in serum testosterone levels due to damage of the testis structure and, consequently, male infertility. The present study aims to evaluate the effects of chronic CsA administration on the ventral prostate tissue ( 1 5 mg/kg per d, for 56 days). Stereological, morphometrical, morphological and ultrastructural observations were employed. The plasmatic testosterone and glucose levels were measured. An androgen receptor (AR) immunohistochemical method was applied on ventral prostate sections. Apoptosis was detected with the terminal deoxynucleotidyl transferase dUTP nick end labeling technique. CsA treatment caused reduction in plasmatic testosterone levels and an increase in glycemia. The volume of all ventral prostate tissue components (lumen, epithelium and muscular and nonmuscular stroma) and ventral prostate weight were reduced in the CsA-treated group. Light and transmission electron microscopy confirmed epithelium atrophy of treated animals. There was no alteration of AR expression or apoptotic index. CsA chronic treatment in the therapeutic doses caused damage to prostate tissue of adult Wistar rats, probably due to increase in the glucose levels and reduction in the plasmatic testosterone levels.

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BACKGROUND: Studies in men are not consistent regarding the effects of thyroid hormone on the production of gonadotropins. In hypothyroidism consequent to diverse causes, an increase or no change in serum luteinizing hormone (LH) have been reported. The attempt to explain the mechanisms involved in this pathology using rats as an experimental model also seems to repeat this divergence, since hypothyroidism has been shown to induce hypogonadotropic hypogonadism, a hypergonadotropic state, or not to affect the basal levels of LH. Notably, the promoter region of the gene encoding the Lh beta subunit and GnRH (gonadotropin-releasing factor) does not contain a thyroid responsive element. Therefore, we investigated the hypothesis that, in male rats, posttranscriptional mechanisms of LH synthesis are altered in hypothyroidism. We also attempted to determine if hypothyroidism directly affects testicular function in male rats. METHODS: Male Wistar rats, 60 days old, were thyroidectomized or sham-operated. After 20 days, they were decapitated, and the pituitaries were collected and analyzed for Lh mRNA, LH content, poly(A) tail length, and polysome profile. The testes were collected and analyzed for Lh receptor mRNA, LH receptor content, and histology using morphometric analyses. The testis, epididymis, seminal vesicle, and ventral prostate were weighed, and serum concentrations of LH, testosterone, thyrotropin (TSH), and triiodothyronine (T3) were measured. RESULTS: Hypothyroidism was associated, in the pituitary, with an increase in Lh mRNA expression, a reduction in Lh mRNA poly(A) tail length, a reduction in the number of LH transcripts associated with polysomes. Pituitary LH was decreased but serum LH was increased from 102 to 543 pg/mL. Despite this, serum testosterone concentrations were decreased from 1.8 to 0.25 ng/mL. A decreased germinative epithelium height of the testes and a reduced weight of androgen-responsive tissues were observed (ventral prostrate: 74 vs. 23 mg/100 g body weight [BW]; seminal vesicle undrained: 280 vs. 70 mg/100 g BW; and seminal vesicle drained: 190 vs. 60 mg/100 g BW). CONCLUSIONS: Hypothyroidism in adult male rats has dual effects on the pituitary testicular axis. It alters posttranscriptional mechanisms of LH synthesis and probably has a direct effect on testicular function. However, these data suggest the possibility that reduced LH bioactivity may account in part for impaired testicular function.

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OBJECTIVE: The aim of this study was to assess the IgE serum levels in juvenile systemic lupus erythematosus patients and to evaluate possible associations with clinical and laboratory features, disease activity and tissue damage. METHODS: The IgE serum concentrations in 69 consecutive juvenile systemic lupus erythematosus patients were determined by nephelometry. IgG, IgM and IgA concentrations were measured by immunoturbidimetry. All patients were negative for intestinal parasites. Statistical analysis methods included the Mann-Whitney, chi-square and Fisher's exact tests, as well as the Spearman rank correlation coefficient. RESULTS: Increased IgE concentrations above 100 IU/mL were observed in 31/69 (45%) juvenile systemic lupus erythematosus patients. The mean IgE concentration was 442.0 +/- 163.4 IU/ml (range 3.5- 9936.0 IU/ml). Fifteen of the 69 patients had atopic disease, nine patients had severe sepsis and 56 patients presented with nephritis. The mean IgE level in 54 juvenile systemic lupus erythematosus patients without atopic manifestations was 271.6 +/- 699.5 IU/ml, and only nine of the 31 (29%) patients with high IgE levels had atopic disease. The IgE levels did not statistically differ with respect to the presence of atopic disease, severe sepsis, nephritis, disease activity, or tissue damage. Interestingly, IgE concentrations were inversely correlated with C4 levels ( r = -0.25, p = 0.03) and with the SLICC/ACR-DI score (r = -0.34, p = 0.005). The IgE concentration was also found to be directly correlated with IgA levels (r = 0.52, p = 0.03). CONCLUSIONS: The present study demonstrated for the first time that juvenile systemic lupus erythematosus patients have increased IgE serum levels. This increase in IgE levels was not related to allergic or parasitic diseases. Our results are in line with the hypothesis that high IgE levels can be considered a marker of immune dysregulation.

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Background: Prolonged preoperative fasting increases insulin resistance (IR). The authors investigated whether an abbreviated preoperative fast with glutamine (GLN) plus a carbohydrate (CHO)-based beverage would improve the organic response after surgery. Methods: Forty-eight female patients (19-62 years) were randomized to either standard fasting (control group) or to fasting with 1 of 3 different beverages before video-cholecystectomy. Beverages were consumed 8 hours (400 mL; placebo group: water; GLN group: water with 50 g maltodextrine plus 40 g GLN; and CHO group: water with 50 g maltodextrine) and 2 hours (200 mL; placebo: water; GLN: water with 25 g maltodextrine plus 10 g GLN; and CHO: water with 25 g maltodextrine) before anesthesia. Blood samples were collected pre- and postoperatively. Results: The mean (SEM) postoperative homeostasis model assessment-insulin resistance was greater (P < .05) in control patients (4.3 [1.3]) than in the other groups (placebo, 1.6 [0.3]; CHO, 2.3 [0.4]; and GLN, 1.5 [0.1]). Glutathione was significantly higher (P < .01) in the GLN group than in both CHO and control groups. Interleukin-6 increased in all groups except the GLN group. The C-reactive protein/albumin ratio was higher (P < .05) in controls than in CHO and GLN groups. The nitrogen balance was less negative in GLN (-2.5 [0.8] gN) than in both placebo (-9.0 [2] gN; P = .001) and control (-6.6 [0.4] gN; P = .04) groups. Conclusions Preoperative intake of a GLN-enriched CHO beverage appears to improve IR and antioxidant defenses and decreases the inflammatory response after video-cholecystectomy. (JPEN J Parenter Enteral Nutr. 2012; 36: 43-52)

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Recent studies have implicated adiponectin and other adipocytokines in brain function, particularly in processes related to memory and cognition. Blood levels of adiponectin are reduced in patients with primary cognitive disorders, such as Alzheimer's disease and mild cognitive impairment, and in adult patients with major depression. The aim of the present study is to determine serum levels of adiponectin in a sample of elderly patients with major depressive disorder (MOD) as compared to healthy older adults, and to examine the correlations between adiponectin levels and parameters indicative of mood and cognitive state. We recruited fifty-one unmedicated outpatients with late-life depression (LLD) and 47 age-matched controls in this study. The diagnosis of MDD was made according to the DSM-IV criteria, and the severity of depressive episode was determined with the 21-item Hamilton Depression Scale (HORS). Cognitive state was ascertained with the Cambridge Cognitive Test (CAMCOG) and the Mini-Mental State Examination (MMSE). Serum concentrations of adiponectin were determined using a sandwich ELISA method. Serum levels of adiponectin were significantly reduced in individuals with LLD (F = p < 0.001). Adiponectin level remained significantly reduced in after controlling for BMI index, scores on the CAMCOG, MMSE and HDRS and educational level (p < 0.001). Adiponectin levels showed a negative correlation with HORS scores (r = -0.59, p < 0.001) and BMI index (r = -0.42, p < 0.001); and showed a positive correlation with CAMCOG (r = 0.34, p < 0.01) and MMSE scores (r = 0.20, p = 0.05). The availability of circulating adiponectin is reduced in older adults with major depression, with likely implications on cognitive and mood state. Additional studies are required to determine whether this abnormality pertains to the pathophysiology of geriatric depression per se, or is a consequence of the morbid state. (C) 2012 Elsevier Ltd. All rights reserved.

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Introduction: Rodent-borne hantaviruses cause severe human diseases. We completed a serological survey of hantavirus infection in rural inhabitants of Turvo County, in the southern state of Santa Catarina, Brazil, in which seropositivity for hantavirus was correlated to previous disease in the participants. Methods: The levels of IgG antibodies to hantavirus Araraquara in the sera of 257 individuals were determined using an immunoenzymatic assay. Results: IgG antibodies to hantavirus were found in 2.3% of the participants. All seropositive participants reported previous disease with symptoms suggestive of hantavirus cardiopulmonary syndrome. Conclusions: Human infections causing unreported cardiopulmonary syndrome probably occur in the southern state of Santa Catarina.

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Activin A is a growth factor, produced by the endometrium, whose actions are modulated by the binding protein follistatin. Both proteins are detectable in the peripheral serum and their concentrations may be increased in women with endometriosis. The present study was designed to evaluate whether serum levels of activin A and follistatin are altered, and therefore have a potential diagnostic value, in women with peritoneal, ovarian and deep infiltrating endometriosis. We performed a multicenter controlled study evaluating simultaneously serum activin A and follistatin concentrations in women with and without endometriosis. Women with endometriosis (n 139) were subdivided into three groups: peritoneal endometriosis (n 28); ovarian endometrioma (n 61) and deep infiltrating endometriosis (n 50). The control group (n 75) consisted of healthy women with regular menstrual cycles. Blood samples were collected from a peripheral vein and assayed for activin A and follistatin using commercially available enzyme immunoassay kits. The ovarian endometrioma group had serum activin A levels significantly higher than healthy controls (0.22 0.01 ng/ml versus 0.17 0.01 ng/ml, P 0.01). None of the endometriosis groups had serum follistatin levels which were significantly altered compared with healthy controls; however, levels found in the endometrioma group (2.34 0.32 ng/ml) were higher than that in the deep endometriosis group (1.50 0.17 ng/ml, P 0.05). The area under the receiver operating characteristic curve of activin A was 0.700 (95 confidence interval: 0.6050.794), while that of follistatin was 0.620 (95 confidence interval: 0.5100.730) for the diagnosis of ovarian endometrioma. The combination of both markers into a duo marker index did not improve significantly their diagnostic accuracy. The present study demonstrated that serum activin A and follistatin are not significantly altered in peritoneal or deep infiltrating endometriosis and have limited diagnostic accuracy in the diagnosis of ovarian endometrioma.

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Increased uric acid (UA) is strongly linked to cardiovascular disease. However, the independent role of UA is still debated because it is associated with several cardiovascular risk factors including obesity and metabolic syndrome. This study assessed the association of UA with increased high-sensitivity C-reactive protein (hs-CRP), increased ratio of triglyceride to high-density lipoprotein cholesterol (TG/HDL), sonographically detected hepatic steatosis, and their clustering in the presence and absence of obesity and metabolic syndrome. We evaluated 3,518 employed subjects without clinical cardiovascular disease from November 2008 through July 2010. Prevalence of tis-CRP >= 3 mg/L was 19%, that of TG/HDL >= 3 was 44%, and that of hepatic steatosis was 43%. In multivariable logistic regression after adjusting for traditional cardiovascular risk factors and confounders, highest versus lowest UA quartile was associated with hs-CRP >= 3 mg/L (odds ratio [OR] 1.52, 95% confidence interval [CI] 1.01 to 2.28, p = 0.04), TG/HDL >= 3 (OR 3.29, 95% CI 2.36 to 4.60, p <0.001), and hepatic steatosis (OR 3.10, 95% CI 2.22 to 4.32, p <0.001) independently of obesity and metabolic syndrome. Association of UA with hs-CRP >= 3 mg/L became nonsignificant in analyses stratified by obesity. Ascending UA quartiles compared to the lowest UA quartile demonstrated a graded increase in the odds of having 2 or 3 of these risk conditions and a successive decrease in the odds of having none. In conclusion, high UA levels were associated with increased TG/HDL and hepatic steatosis independently of metabolic syndrome and obesity and with increased hs-CRP independently of metabolic syndrome. (C) 2012 Elsevier Inc. All rights reserved. (Am J Cardiol 2012;110:1787-1792)

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Background: Iron supplementation is a common recommendation to chronic kidney disease patients undergoing hemodialysis (HD). However, iron excess is closely associated with lipid peroxidation and, it is well known that electronegative low-density lipoproteins (LDL[-]) are present at higher plasma concentrations in diseases with high cardiovascular risk such as chronic kidney disease. Thus, the aim of this study was to investigate whether ferritin levels are associated with LDL(-) levels in HD patients. Design: This was a cross-sectional study. Setting: This study was conducted from a private clinic in Rio de Janeiro, Brazil. Patients: The study included 27 HD patients and 15 healthy subjects. Methods and Procedures: Twenty-seven HD patients (14 men, 58.6 +/- 10 years, 62.2 +/- 51.4 months on dialysis, and body mass index: 24.4 +/- 4.2 kg/m(2)) were studied and compared with 15 healthy individuals (6 men, 53.8 +/- 15.4 years, body mass index: 24.5 +/- 4.3 kg/m(2)). Serum LDL(-) levels were measured using the enzyme-linked immunosorbent assay method; ferritin levels by commercially available kits, and tumor necrosis factor-alpha, interleukin-6, monocyte chemoattractant protein-1, and plasminogen activator inhibitor-1 were determined with a multiplex assay kit manufactured by R&D Systems. Results: The HD patients presented higher LDL(-) and tumor necrosis factor-alpha levels (0.15 +/- 0.13 U/L and 5.9 +/- 2.3 pg/mL, respectively) than healthy subjects (0.07 +/- 0.05 U/L and 2.3 +/- 1.3 pg/mL, respectively) (P = .0001). The mean ferritin level in HD patients was 1,117.5 +/- 610.4 ng/mL, and 90% of patients showed ferritin levels exceeding 500 ng/mL. We found a positive correlation between LDL(-) and ferritin in the patients (r = 0.48; P = .01), and ferritin was a significant contributor to LDL(-) concentrations independent of inflammation. Conclusions: Excess body iron stores for HD patients was associated with signs of increased oxidative stress, as reflected by increased LDL(-) levels in HD patients. (C) 2012 by the National Kidney Foundation, Inc. All rights reserved.

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eNOS activation resulting in mitochondrial biogenesis is believed to play a central role in life span extension promoted by calorie restriction (CR). We investigated the mechanism of this activation by treating vascular cells with serum from CR rats and found increased Akt and eNOS phosphorylation, in addition to enhanced nitrite release. Inhibiting Akt phosphorylation or immunoprecipitating adiponectin (found in high quantities in CR serum) completely prevented the increment in nitrite release and eNOS activation. Overall, we demonstrate that adiponectin in the serum from CR animals increases NO center dot signaling by activating the insulin pathway. These results suggest this hormone may be a determinant regulator of the beneficial effects of CR.

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The human luteinizing hormone/chorionic gonadotropin receptor (LHCGR) plays a fundamental role in male and female reproductive physiology. Over the past 15 years, several homozygous or compound heterozygous loss-of-function mutations in the LHCGR gene have been described in males and females. In genetic males, mutations in LHCGR were associated with distinct degrees of impairment in pre- and postnatal testosterone secretion resulting in a phenotypic spectrum. Patients with the severe form of LH resistance have predominantly female external genitalia and absence of secondary sex differentiation at puberty. Patients with milder forms have predominantly male external genitalia with micropenis and/or hypospadias or only infertility without ambiguity. The undermasculization is associated with low basal, as well as human CG-stimulated, testosterone levels and elevated LH levels after pubertal age, without abnormal step-up in testosterone biosynthesis precursors. The testes have only slightly reduced size but mature Leydig cells are absent or scarce (Leydig cell hypoplasia). Genetic females with inactivating LHCGR mutations have female external genitalia, spontaneous breast and pubic hair development at puberty, and normal or late menarche followed by oligoamenorrhea and infertility. Estradiol and progesterone levels are normal for the early to midfollicular phase, but do not reach ovulatory or luteal phase levels. Serum LH levels are high whereas follicle-stimulating hormone levels are normal or only slightly increased. Pelvic ultrasound has demonstrated a small or normal uterus and normal or enlarged ovaries with cysts. The inactivating mutations of the LHCGR have provided important insights into distinct physiological roles of LH in reproduction of both sexes.