Endocrine disrupter action in ruminants: A study of the effects of Ipomoea carnea in adult male goats

Ipomoea carnea is a toxic plant in Brazil and other tropical countries that often poisons livestock; its primary toxin is swainsonine. Some substances that interact with the endocrine system have been called endocrine disruptors (EDs). Considering swainsonine's mode of action, it is feasible to hypothesize that this compound could act as an ED. Bisphenol A (BPA), an estrogen-mimic, is considered a classical ED in rodents. This study aimed to evaluate the possible ED actions of I. cameo and BPA in male goats. Seventeen adult male goats were divided into three homogeneous groups: control (C, n = 5); IC (n = 6, received 5.0 g/kg body weight of freshly harvested I. cornea per day), and BPA (n = 6, received 25.0 mg/kg body weight of BPA per day). The experimental period was 120 days. During the experiment, blood samples were collected at 0, 30, 60, 90 and 120 days for biochemical and hormonal evaluations. On the same days, semen samples were collected for andrological evaluation, and scrotal circumference and testicular consistency were determined. The males were castrated on day 121, and fragments of testicle and epididymis were collected for histopathological evaluation. A decrease in serum T3 and T4 was observed in the IC group as well as an increase in the number of sperm with morphological alterations. In the BPA group, reduced serum 14 and a decreased percentage of sperm with plasma membrane integrates were observed. A histopathological examination revealed the vacuolar degeneration of Sertoli cells and areas of laminar patterns of calcium deposits in the IC group and vacuolar degeneration in the rete testis in the BPA group. These results indicate that both I. cameo and BPA are potential EDs in goats. This study emphasized the susceptibility of livestock to ED actions. We also demonstrated the action of I. cameo acting as EDs in the endocrine and reproductive systems. (C) 2014 Elsevier B.V. All rights reserved.

Modulação androgênica e estrogênica na próstata: uma abordagem em modelos experimentais de roedores com enfoque na biologia estrutural

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bisphenol A removal from wastewater using self-organized TIO2 nanotubular array electrodes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

DETECTION of BISPHENOL A on A SCREEN-PRINTED CARBON ELECTRODE IN CTAB MICELLAR MEDIUM

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effects of atrazine on female Wistar rats: Morphological alterations in ovarian follicles and immunocytochemical labeling of 90 kDa heat shock protein

Fertility in female mammals may be affected by a variety of endocrine disrupters present in the environment. Herbicide atrazine is an example of endocrine disrupter employed in agriculture, which disrupts estrous cyclicity in rats. Aiming to characterize morphologically the effect of low and sublethal doses of atrazine on the ovaries of Wistar rats, in an effort to determine the possible intrafollicular target site through which this herbicide acts adult females were submitted to both subacute and subchronic treatments. Additionally, immunocytochemical labeling of 90 kDa heat shock protein (HSP90) was performed in order to evaluate the role played by this protein in the ovary, under stressed conditions induced by herbicide exposure. The results indicated that atrazine induced impaired folliculogenesis, increased follicular atresia and HSP90 depletion in female rats submitted to subacute treatment, while the subchronic treatment with low dose of atrazine could compromise the reproductive capacity reflected by the presence of multioocytic follicle and stress-inducible HSP90. © 2007 Elsevier Ltd. All rights reserved.

A persistent organic pollutant related with unusual high frequency of hermaphroditism in the neotropical anuran Physalaemus cuvieri Fitzinger, 1826

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeitos da flutamida na morfologia dos órgãos reprodutivos e fígado de Rhinella schneideri (Anura: Bufonidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Characterization of the Interactions between Endocrine Disruptors and Aquatic Humic Substances from Tropical Rivers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The adaptive compensations in endocrine pancreas from glucocorticoid-treated rats are reversible after the interruption of treatment

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Insulin and glucose sensitivity, insulin secretion and beta-cell distribution in endocrine pancreas of the fruit bat Artibeus lituratus

The fruit bat Artibeus lituratus absorbs large amounts of glucose in short periods of time and maintains normoglycemia even after a prolonged starvation period. Based on these data, we aimed to investigate various aspects related with glucose homeostasis analyzing: blood glucose and insulin levels, intraperitoneal glucose and insulin tolerance tests (ipGTT and ipITT), glucose-stimulated insulin secretion (2.8, 5.6 or 8.3 mmol/L glucose) in pancreas fragments, cellular distribution of beta cells, and the amount of pAkt/Akt in the pectoral muscle and liver. Blood glucose levels were higher in fed bats (6.88 +/- 0.5 mmol/L) than fasted bats (4.0 +/- 0.8 mmol/L), whereas insulin levels were similar in both conditions. The values of the area-under-the curve obtained from ipGTT were significantly higher when bats received 2 (5.5-fold) or 3 g/kg glucose (7.5-fold) b.w compared to control (saline). These bats also exhibited a significant decrease of blood glucose values after insulin administration during the iplTT. Insulin secretion from fragments of pancreas under physiological concentrations of glucose (5.6 or 8.3 mmol/L) was similar but higher than in 2.8 mmol/L glucose 1.8- and 2.0-fold, respectively. These bats showed a marked beta-cell distribution along the pancreas, and the pancreatic beta cells are not exclusively located at the central part of the islet. The insulin-induced Akt phosphorylation was more pronounced in the pectoral muscle, compared to liver. The high sensitivity to glucose and insulin, the proper insulin response to glucose, and the presence of an apparent large beta-cell population could represent benefits for the management of high influx of glucose from a carbohydrate-rich meal, which permits appropriate glucose utilization. (C) 2010 Elsevier B.V. All rights reserved.

Functional alterations in endocrine pancreas of rats with different degrees of dexamethasone-induced insulin resistance

Objectives: We have analyzed the peripheral insulin and glucose sensitivity in vivo, and islet function ex vivo in rats with different degrees of insulin resistance induced by dexamethasone (DEX).Methods: Dexamethasone, in the concentrations of 0.1 (DEX 0.1), 0.5 (DEX 0.5), and 1.0 mg/kg body weight (DEX 1.0) was administered daily, intraperitoneally, to adult Wistar rats for 5 days, whereas controls received saline.Results: Dexamethasone treatment induced peripheral insulin resistance in a dose-dependent manner. At the end of the treatment, only DEX 1.0 rats showed significant increase of postabsorptive blood glucose and serum triglycerides, and nonesterified fatty acids levels. Incubation of pancreatic islets in increasing glucose concentrations (2.8-22 mM) led to an augmented insulin secretion in all DEX-treated rats. Leucine, carbachol, and high KCl concentrations induced the insulin release in DEX 0.5 and DEX 1.0, whereas arginine augmented secretion in all DEX-treated groups.Conclusions: We demonstrate that in DEX 0.5 and, especially in DEX 0.1 groups, but not in DEX 1.0, the adaptations that occurred in the endocrine pancreas are able to counteract metabolic disorders (glucose intolerance and dyslipidemia). These animal models seem to be interesting approaches for the study of degrees of subjacent effects that may mediate type 2 diabetes (DEX 1.0) and islet function alterations, without collateral effects (DEX 0.1 and DEX 0.5).

Cardiorespiratory and endocrine effects of endogenous opioid antagonism by naloxone in ponies anaesthetised with halothane

Halothane depresses cardiorespiratory function and activates the pituitary-adrenal axis, increasing beta endorphin. In horses, beta endorphin may enhance the anaesthetic-associated cardiorespiratory depression and mortality risk. The authors studied endogenous opioid effects on cardiorespiratory function and pituitary-adrenal activity in halothane-anaesthetised ponies by investigating opioid antagonism by naloxone. Six ponies were anaesthetised three times (crossover design). Anaesthesia was induced with thiopentone and maintained with 1.2 per cent halothane for 2 hours. Immediately after induction, naloxone was administered either intra venously (0.5 mg kg(-1) bolus then 0.25 mg kg(-1) hour(-1) for 2 hours) or intrathecally (0.5 mg) or was replaced by saline as control. Pulse and respiratory rates, arterial blood gases, cardiac output and plasma cortisol and adrenocorticotrophic hormone (ACTH) concentrations were measured. All groups developed cardiorespiratory depression (40 per cent decrease in cardiac output) and plasma cortisol increased. Plasma ACTH concentration was higher in ponies treated with intrathecal naloxone. Endogenous opioids may inhibit ACTH Secretion, attenuating the stress response to halothane anaesthesia in equidae. (C) 2001 Harcourt Publishers Ltd.

Performance, incidence of metabolic disturbances and endocrine variables of food-restricted male broiler chickens

1. This experiment was carried out to evaluate the productive and physiological consequences of a slight but long term food restriction of male broiler chickens from 2 commercial strains.2. Cobb-500 and Ross chickens were submitted to a 20% food restriction from 8 to 21 d of age. Strain, food programme and their interactive effects were analysed in terms of consequences upon performance, mortality, incidence of sudden death syndrome (SDS) and ascites syndrome (AS), index of right cardiac hypertrophy and plasma concentrations of hormones related to metabolism and growth (T-3, T-4, T-3:T-4 ratio, IGF-I and GH).3. Although some catch-up growth was observed by refeeding previously restricted birds after 22 d of rearing, food restriction decreased (P less than or equal to 0.05) body weight at market age (42 d) irrespective of the strain, but improved (P less than or equal to 0.05) food conversion.4. The incidence of mortality was not high in non-restricted birds but SDS and AS caused more than 50% of deaths. Hypertrophic cardiac index was observed in chickens of both strains after 4 weeks of age and was higher in ad libitum fed birds.5. During the period of food restriction, plasma T-3 and IGF-I concentrations decreased whereas plasma T-4 and GH concentrations increased compared to those of the age-matched ad libitum fed counterparts. During the subsequent ad libitum feeding period, few differences in circulating hormone concentrations were observed, except for the higher mean CH litres in previously food-restricted chickens at 35 d of age.6. These results indicate that even a non-severe food restriction negatively affects body weight of 42-d-old male broilers but these are benefits with improved food efficiency and diminished mortality from metabolic disturbances. The hormone results suggest that the degree of food restriction applied was not severe because there was a very fast adaptive response with small and transient alterations in T-3, T-4 and GH plasma concentrations during the period of compensatory growth.

Ultrasonographic and endocrine aspects of follicle deviation, and acquisition of ovulatory capacity in buffalo (Bubalus bubalis) heifers

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Differential nutritional, endocrine, and cardiovascular effects in obesity-prone and obesity-resistant rats fed standard and hypercaloric diets

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)