Navegando por Palavras-chave "Rats, Inbred SHR"

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    Caracterização dos efeitos da exposição aos componentes do cigarro sobre o controle neural do sistema cardiovascular em ratos normotensos e ratos espontaneamente hipertensos
    (Universidade Federal de São Paulo (UNIFESP), 2011-06-29) Valenti, Vitor Engrácia [UNIFESP]; Ferreira, Celso [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    Objectives: To evaluate the effects of sidestream cigarette smoke (SSCS) on neural control of cardiovascular system in normotensive and spontaneously hypertensive rats (SHR). Method: Wistar, Wistar-Kyoto rats (WKY) and SHR were exposed to SSCS for three weeks, five days per week, 180 minutes per day at a concentration of carbon monoxide between 100 and 300 ppm. Baroreflex was stimulated with a vasodepressor dose of sodium nitroprusside (NPNa, 50ìg/kg, iv) and with a pressor dose of phenylephrine (PE, 8ìg/kg, iv). In order to evaluate the effects of catalase inhibition into the fourth cerebral ventricle (4th V) on cardiovascular responses, we injected the catalase inhibitor 3-amino-1,2,4-triazole (ATZ, ìg/100ìL 0.01). Results: It was observed in Wistar rats exposed to SSCS that catalase inhibition caused more intense responses on basal HR and bradycardic peak. Central catalase inhibition affected in a higher intensity baseline HR and bradycardic peak WKY rats exposed to SSCS. On the other hand, in SHR SSCS exposure affected the tachycardic peak after central inhibition of catalase in a higher intensuty. Conclusion: Exposure to SSCS alters the sympathetic component of the baroreflex in WKY and SHR and caused more severe cardiovascular responses to catalase inhibition into the 4th V in Wistar and WKY rats.
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    Efeito da sobreposição de um modelo de obesidade neuroendócrina experimental e hipertensão arterial sobre a pressão arterial, peso corporal e parâmetros metabólicos e renais de ratos
    (Sociedade Brasileira de Nefrologia, 2011-09-01) Ferreira, Lara Beatriz Delfino [UNIFESP]; Cesaretti, Mario Luis Ribeiro; Voltera, Aline Francisco [UNIFESP]; Ginoza, Milton [UNIFESP]; Kohlmann Junior, Osvaldo [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Pontifícia Universidade Católica de São Paulo
    INTRODUCTION: Increased body mass index and the metabolic syndrome are associated with decreased renal function and the development of end-stage kidney disease. OBJECTIVE: To evaluate the effect of the overlap between an experimental model of obesity and genetic hypertension on the blood pressure, body weight and metabolic and kidney parameters of rats. METHODS: We studied male rats of the Wistar (WST) and spontaneously hypertensive rats (SHR) strains. Monosodium glutamate (MSG) was administered in the neonatal period to both strains, to make up two groups: WST + MSG and SHR + MSG. Animals in the control groups (WST and SHR) received saline. After completing three months of life, a 12-week follow-up period ensued, during which bi-weekly measurements of body weight (BW) and tail-cuff blood pressure (TCBP) were obtained. Microalbuminuria was analyzed at weeks 0, 4, 8 and 12. At the end of the follow-up period, blood was obtained for fasting glucose, plasma creatinine, and lipid profile determinations. The kidneys were removed, stained, and the glomerular sclerosis index was calculated. RESULTS: The administration of MSG produced higher percentage body weight gain, higher fasting blood glucose and a higher degree of glomerular injury in WST-MSG and MSG-SHR rats, compared to their controls. Greater urinary albumin excretion was observed in SHR + MSG rats, when compared to SHR. There was no statistical difference in the TCBP, creatinine, and lipid profile. CONCLUSIONS: The association of neuroendocrine obesity and arterial hypertension promoted morphological and functional changes in the glomerulus. These changes were more severe than those observed in hypertensive-only rats.