Dexamethasone treatment in vivo counteracts the functional pancreatic islet alterations caused by malnourishment in rats

The effects of dexamethasone (Dex) on the metabolic parameters, peripheral insulin, and glucose sensitivity in vivo as well as on islet function ex vivo of rats submitted to low-protein diet were analyzed. Dexamethasone (1.0 mg/kg body weight) was administered intraperitoneally daily to adult Wistar rats fed on a normal-protein diet or low-protein diet (LPD) for 5 days, whereas control rats fed on a normal-protein diet or low-protein diet (LP) received saline alone. At the end of the experimental period, LP rats showed a significant reduction in serum insulin, total serum protein, and serum albumin levels compared with rats fed on a normal-protein diet (P < .05). All these parameters tended to be normalized in LPD rats (P < .05); furthermore, these rats exhibited increased serum glucose and nonesterified fatty acid levels compared with LP rats (P < .05). Rats submitted to the low-protein diet demonstrated normal peripheral glucose sensitivity and improved peripheral insulin sensitivity, which was reversed by Dex treatment. A reduced area of islets from LP rats was partially recovered in LPD rats (P < .05). At 16.7 mmol/L glucose, insulin secretion from LPD islets was also partially recovered and was significantly higher than that from LP islets (P < .05). In conclusion, induction of insulin resistance by Dex treatment reverses most of the metabolic alterations in rats submitted to a low-protein diet. In addition, several islet functions were also improved by Dex, confirming the plasticity of pancreatic islets in adverse conditions. (C) 2008 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).

Pancreatic islets from dexamethasone-treated rats show alterations in global gene expression and mitochondrial pathways

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

Dynamics of inter-modality re-weighting during human postural control

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Age-related changes in postural control sensory reweighting

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Equilíbrio postural e risco para queda em idosos da cidade de Garça, SP

OBJETIVOS: Avaliar o equilíbrio postural e o risco de quedas em idosos institucionalizados e não-institucionalizados. MÉTODOS: Foram incluídos no estudo 45 idosos institucionalizados e 43 idosos não-institucionalizados. O equilíbrio e o risco de quedas foram avaliados através da Escala de Equilíbrio de Berg. A comparação do equilíbrio entre os grupos foi feita por meio do teste de Mann-Whitney. Foi avaliado o risco para queda entre as populações. Adotou-se um valor de p ≤ 0,05 como significante. RESULTADOS: Houve diferença entre os escores da Escala de Berg nas populações estudadas (p < 0,0001). Os resultados mostraram que a população institucionalizada apresenta nove vezes mais risco de cair do que idosos da comunidade (p=0,0001). CONCLUSÕES: Os resultados indicam que o equilíbrio postural é menor na população institucionalizada, aumentando seu risco de cair.

Alterations in the intestinal wall due to protein malnutrition in rats. Evaluation of the rupture strength and the tissue's collagen

OBJETIVO: Avaliar o efeito da desnutrição protéica na parede intestinal do rato através da medida de força de ruptura e dosagem do colágeno tecidual no íleo e cólon distal. MÉTODOS: Foram utilizados 120 ratos, pesando em média 100g, que receberam durante 07 dias uma dieta padrão, contendo 20% de caseína para adaptação dos animais as condições do biotério. Após esse período os animais foram divididos em dois grupos de 60, o controle denominado grupo um que recebeu a dieta padrão, e o grupo teste denominado grupo dois, que recebeu dieta hipoprotéica contendo 2% de caseína. Os dois grupos receberam suas respectivas dietas por um período de 21 dias. Após esse período iniciou-se o sacrifício seqüencial dos animais em ambos os grupos, em número de 12 animais em cada momento, correspondendo ao dia Zero (MO), 4º dia (M1), 7º dia (M2), 14º dia (M3), e 21º dia (M4) sendo mantida a mesma dieta até o final do sacrifício. em cada momento foram avaliados o peso corpóreo, albumina sanguínea, hidroxiprolina tecidual, relação hidroxiprolina/proteína tecidual e a força de ruptura no segmento ileal e cólico dos animais. RESULTADOS: Observou-se que a força de ruptura do segmento ileal e do cólon distal foi menor nos animais desnutridos (Grupo 2). A perda da resistência mecânica foi maior no segmento do cólon distal do que no segmento ileal, provavelmente pela menor concentração do colágeno tecidual no cólon distal. CONCLUSÃO: A desnutrição protéica induz a diminuição da resistência mecânica no íleo e no cólon distal associado a diminuição do colágeno tecidual na parede intestinal.

Alterations in myocardial collagen content affect rat papillary muscle function

We investigated the influence of myocardial collagen volume fraction (CVF, %) and hydroxyproline concentration (mu g/mg) on rat papillary muscle function. Collagen excess was obtained in 10 rats with unilateral renal ischemia for 5 wk followed by 3-wk treatment with ramipril (20 mg . kg(-1) . day(-1)) (RHTR rats; CVF = 3.83 +/- 0.80, hydroxyproline = 3.79 +/- 0.50). Collagen degradation was induced by double infusion of oxidized glutathione (GSSG rats; CVF 5 2.45 +/- 0.52, hydroxyproline = 2.85 +/- 0.18). Nine untreated rats were used as controls (CFV = 3.04 +/- 0.58, hydroxyproline = 3.21 +/- 0.30). Active stiffness (AS; g . cm(-2) . %L-max(-1)) and myocyte cross-sectional area (MA; mu m(2)) were increased in the GSSG rats compared with controls [AS 5.86 vs. 3.96 (P< 0.05); MA 363 +/- 59 vs. 305 +/- 28 (P< 0.05)]. In GSSG and RHTR groups the passive tension-length curves were shifted downwards, indicating decreased passive stiffness, and upwards, indicating increased passive stiffness, respectively. Decreased collagen content induced by GSSG is related to myocyte hypertrophy, decreased passive stiffness, and increased AS, and increased collagen concentration causes myocardial diastolic dysfunction with no effect on systolic function.

Could zinc prevent reproductive alterations caused by cigarette smoke in male rats?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of rutin treatment on biochemical alterations in experimental diabetes

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

Plasma concentrations and placental immunostaining of interleukin-10 and tumor necrosis factor-alpha as predictors of alterations in the embryo-fetal organism and the placental development of diabetic rats

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

Vaginal Flora Alterations and Clinical Symptoms in Low-Risk Pregnant Women

Background: To evaluate associations between alterations in vaginal flora and clinical symptoms in low-risk pregnant women. Methods: Vaginal specimens from 245 pregnant women were analyzed by microscopy for vaginal flora. Signs and symptoms of vaginal infection were determined by patient interviews and gynecologic examinations. Results: Abnormal vaginal flora was identified in 45.7% of the subjects. The final clinical diagnoses were bacterial vaginosis (21.6%), vaginal candidosis (10.2%), intermediate vaginal flora (5.2%), aerobic vaginitis (2.9%), mixed flora (2.9%) and other abnormal findings (2.9%). The percentage of women with or without clinical signs or symptoms was not significantly different between these categories. The presence of vaginal odor or vaginal discharge characteristics was not diagnostic of any specific flora alteration; pruritus was highly associated with candidosis (p < 0.0001). Compared to women with normal flora, pruritus was more prevalent in women with candidosis (p < 0.0001), while vaginal odor was associated with bacterial vaginosis (p = 0.0026). Conclusion: The prevalence of atypical vaginal flora is common in our low-risk pregnant population and is not always associated with pathology. The occurrence of specific signs or symptoms does not always discriminate between women with different types of atypical vaginal flora or between those with abnormal and normal vaginal flora. Copyright (C) 2010 S. Karger AG, Basel

Effect of hormone therapy on postural balance in postmenopausal women

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

Time-dependent alterations of soluble and cellular components in human milk

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

Evaluation of postural balance in postmenopausal women and its relationship with bone mineral density- a cross sectional study

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