Hipothalamy-pituitary axis: Effects of physical training in rats administered with dexamethasone

Aim. To investigate the effects of physical training associated to dexamethasone administration in carbohydrate metabolism and adrenocorticotrophic hormone (ACTH) release. Materials and methods. Young Wistar rats were divided into four groups: sedentary control (CS), sedentary dexanzethasone (DxS), trained control (CT) and trained dexamethasone (DxT). The rats were submitted to swimming training associate to administration of dexamethasone for ten weekends. Before sacrifice the rats received Subcutaneous insulin to calculate the maximum decreased in blood glucose. Venous blood was sampled obtained at the end experiment period to determine glucose, insulin, free fatty acids (FFA) and ACTH. Gastrocnemius and liver tissue samples were used to determination glycogen, and adipose epididimal tissue was used to measured the weight. Results. Dexamethasone administration provoke insulin resistance and the physical training reverted this aspect. Training promoted increase in muscle and liver glycogen store and a high utilization of FFA. Moreover the dexamethasone provoke decreased of ACTH release in response to acute exercise, showing marked differences in the functioning of the hypothalamy pituitary-adrenal (HPA) axis between groups of rats. Conclusions. a) Low-dose of dexamethasone promote several side effects in metabolism intermediary and chronic exposure to steroid was associated with insulin resistance; b) the regular swimming exercise promoted increased insulin sensitiviry Therefore. exercise can override the dexametasone negative feedback of the HPA axis activation in rats.

Biodisponibilidade de fontes orgânicas e inorgânicas de zinco em ovinos

This research was done to compare the effects of different zinc sources and doses in the Santa Ines sheep diet. Forty lambs at weaning, with 18,4kg BW were randomly allotted and fed 10 treatments: 1- base diet without zinc supplementation; 2- base diet + 200mg Zn/kg of DM as zinc oxide; 3- base diet + 400mg Zn/kg of DM as zinc oxide; 4- base diet + 600mg Zn/kg of DM as zinc oxide; 5- base diet + 200mg Zn/kg of DM as amino acid zinc; 6- base diet + 400mg Zn/kg of DM as amino acid zinc; 7- base diet + 600mg Zn/kg of DM as amino acid zinc; 8- base diet + 200mg Zn/kg of DM as proteinato zinc; 9- base diet + 400mg Zn/kg of DM as proteinato zinc; 10- base diet + 600mg Zn/kg of DM as proteinato zinc. The animals were weighed and sampled for blood zinc analysis, phosphatase alkaline analysis and immunoglobulins G and M analysis. At the end of the experiment liver samples were collected to study the zinc hepatic levels. There was no difference in phosphatase alkaline levels, hepatic zinc levels and weight gain (P>0,05) but differences (P<0,05) in plasmatic zinc levels and in IgG and IgM levels were observed. Based on liver tissue uptake, estimates of the zinc bioavailability, through the regression equations showed that the organic and inorganic sources of zinc did not differ.

Diferenciação hepatocítica de células-tronco mesenquimais da medula óssea humana

Some recent articles have reported that mesenchymal stem cells (MSCs) can be induced to express hepatocyte markers by transplanting them into animal models of liver damage, or by in vitro culture with growth factors and cytokines. In this study, the aim is to evaluate the behavior of MSCs subjected to induction of hepatocyte differentiation. The MSCs were isolated from the bone marrow of 4 normal donors, characterized and subjected to both in vitro and in vivo induction of hepatocyte differentiation. The in vitro induced cells showed morphological changes, acquiring hepatocyte-like features. However, the immunophenotype of these cells was not modified. The induced cells exhibited no increase in albumin, cytokeratin 18 or cytokeratin 19 transcripts, when analyzed by real-time RT-PCR. The expression of albumin, cytokeratin 18 and alpha fetoprotein was also unchanged, according to immunofluorescence tests. In vivo, the MSC demonstrated a potential to migrate to damaged liver tissue in immunodeficient mice. Taken together, the results suggest that bone marrow MSCs are incapable of in vitro differentiation into hepatocytes by the approach used here, but are capable of homing to damaged hepatic tissue in vivo, suggesting a role for them in the repair of the liver. This contribution to tissue repair could be associated with a paracrine effect exerted by these cells.

Tratamento hepatoprotetor favorece a resposta leucocitária de ratos wistar intoxicados por CCL4

The aims of this investigation was to evaluate the effect of hepatoprotective treatments with a compound prepared by the association of N-Acetyl DL-Methionine (5%) + Choline chloride (2%) + Caffeine (1%) + Thiamine hydrochloride (1%) + Nicotinamida (0,5%)+ Pyridoxine hydrochloride (0.04%), administered through intramuscular (IM) route, at doses of 0.2, 0.6 and 1.0 mL/kg of BW, through the study of leukocytes responses in rats submitted to acute intoxication with CCl4. 147 females were randomized into 21 groups, performing five different treatments, which were evaluated seven animals in four periods: two, four, six and eight days after CCl4-induced intoxication. In this study, it was observed absolute eosinophilia and monocytosis in animals untreated and treated with the lowest dose of 0.2 mL. These responses were significantly better in animals treated with 0.6 and 1.0 mL/ kg BW. The untreated animals showed thrombocytopenia, when compared to treated animals. Absolute neutropenia and lymphocytosis was observed in all rats intoxicated with CCl4, there is no difference among treatments. The analysis of white blood cells demonstrated that the hepatoprotective treatments favored the leukocyte response, by act beneficially on the population of these cells, supporting the hypothesis that these events may reduce the deleterious effects in liver tissue after intoxication by CCl4.

Histochemical and ultrastructural analysis of hepatic glycogen and collagen fibers in alloxan-induced diabetic rats submitted to long-term physical training

Alterations in liver functions are common among diabetic patients, and many symptoms in the liver have been reported, including changes in glycogen stores and in the amount of collagen fibers. The practice of physical training and its morphological effects in this organ, however, are scarcely studied. In order to observe the morphological effects of alloxan-induced diabetes and the alterations arising from the practice of long-term chronic physical training in the liver, samples were collected and processed, and then analyzed by means of the histochemical techniques Periodic Acid-Schiff and Picrosirius-Hematoxylin, and ultrastructural cytochemical test of Afzelius. Through evaluation of the tissue, it was observed a drastic reduction in hepatic glycogen stores of sedentary diabetics, recovered in trained diabetic rats. Furthermore, it was detected a decrease in the content of perisinusoidal collagen fibers in the diabetic liver, also recovered due to the development of a training protocol. On ultrastructural level, cytochemical analysis confirmed the loss of glycogen and the recovery obtained by training. In conclusion, the practice of a long-term chronic physical training protocol may be considered an important assistant in the treatment of diabetes, mitigating the occurrence of possible damages to liver tissue. © 2011 Elsevier Ltd.

Expressão de genes relacionados à função mitocondrial em bovinos Nelore extremos para consumo alimentar residual

Pós-graduação em Genética e Melhoramento Animal - FCAV

Desenvolvimento de metodologias analíticas para avaliação de cálcio, ferro e zinco ligados a proteínas de tecido hepático de Tilápia do Nilo(Oreochromis Niloticus )

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Insulina e dexametasona na aerocistite aguda induzida por Aeromonas hydrophila em tilápias do Nilo, Oreochromis niloticus, Aloxano-diabéticas

Pós-graduação em Medicina Veterinária - FCAV

Atividade antioxidante da bixina sobre os danos causados pelo tetracloreto de carbono no fígado de ratos

Pós-graduação em Ciência Animal - FMVA

Treinamento físico aeróbio e o eixo de crescimento GH/IGF-1 em ratos diabéticos experimentais

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Growth in weight and of some tissues in the bullfrog: fitting nonlinear models during the fattening phase

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

Alterações hepáticas em cães intoxicados experimentalmente por sementes de Crotalaria spectabilis

Pós-graduação em Medicina Veterinária - FCAV

Atividade hipolidêmica e protetora da bixina no fígado de ratos tratados com dieta hipercalórica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of mixture of diazinon and benzo[a]pyrene in Glutathione S-transferase of Nile tilapia

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

Expression of genes related to mitochondrial function in Nellore cattle divergently ranked on residual feed intake

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