Low-Intensity physical activity beneficially alters the ultrastructural renal morphology of spontaneously hypertensive rats

INTRODUCTION AND OBJECTIVE: Kidney disorders can cause essential hypertension, which can subsequently cause renal disease. High blood pressure is also common among those with chronic kidney disease; moreover, it is a well-known risk factor for a more rapid progression to kidney failure. Because hypertension and kidney function are closely linked, the present study aimed to observe the beneficial effects of low-intensity physical activity on structural and ultrastructural renal morphology and blood pressure in normotensive and spontaneously hypertensive rats. METHOD: Male Wistar-Kyoto rats and spontaneously hypertensive rats were randomly allocated into four groups: sedentary or exercised Wistar-Kyoto and sedentary or exercised spontaneously hypertensive rats. The exercise lasted 20 weeks and consisted of treadmill training for 1 hour/day, 5 days/week. RESULTS: The exercised, spontaneously hypertensive rats showed a significant blood pressure reduction of 26 percent. The body masses of the Wistar-Kyoto and spontaneously hypertensive strains were significantly different. There were improvements in some of the renal structures of the animals treated with physical activity: (i) the interdigitations of the proximal and distal convoluted tubules; (ii) the basal membrane of the proximal and distal convoluted tubules; and (iii) in the basal membrane, slit diaphragm and pedicels of the glomerular filtration barrier. The spontaneously hypertensive rats also showed a decreased expression of connexin-43. CONCLUSION: Physical exercise could be a therapeutic tool for improving kidney ultrastructure and, consequently, renal function in hypertensive individuals.

Effects of chronic sucralose sweetener on the labeling of blood constituents with technetium-99m, morphology of red blood cells and the biodistribution of sodium pertechnetate in rats

This work evaluates effects of the sweetener with sucralose on the labeling of blood constituents with technetium- 99m (99mTc), on the morphology of red blood cells (RBC) and on the biodistribution of sodium pertechnetate in Wistar rats. Animals were treated with sweetener for 8 days. Blood samples were withdrawn and the assay of labeling of blood constituents with 99mTc was performed. Blood cells (BC) and plasma (P) were isolated. Aliquots of BC and P were also precipitated, soluble and insoluble fractions separated. The radioactivity in each fraction was counted and percentage of incorporated radioactivity (%ATI) determined. Blood smears were prepared, fixed, stained and the qualitative and quantitative morphology of the RBC was evaluated under optical microscopy. In biodistribution experiments, sodium pertechnetate was administrated, organs and tissues isolated, radioactivity was counted and percentage of incorporated radioactivity per gram (%ATI/g) determined. The data showed no significant alterations in %ATI, morphology of RBC and in %ATI/g in the studied organs.

Neste estudo foram avaliados efeitos do adoçante com sucralose na marcação de constituintes sangüíneos com 99mTc, na morfologia de hemácias e na biodistribuição do pertecnetato de sódio em ratos Wistar. Animais foram tratados com adoçante durante 8 dias. Amostras de sangue foram retiradas e a marcação de constituintes sangüíneos com 99mTc foi realizada. Células sangüíneas (CS) e plasma (P) foram isolados. Alíquotas de CS e P foram precipitadas, fraçõesinsolúvel e solúvel foram separadas. Aradioatividade em cada fração foi contada e o percentual de radioatividade incorporada (%ATI), determinado. Distensões sangüíneas foram preparadas, fixadas, coradas e análise morfológica, qualitativa e quantitativa, de hemácias foi avaliada sob microscopia óptica. Nos experimentos debiodistribuição, pertecnetato de sódio foiadministrado, órgãos e tecidos isolados, a radioatividade contada e o percentual de radioatividade incorporada por grama (%ATI/g), determinada. Os dados sugerem que não houve alterações significativas no %ATI, morfologia de hemácias e no %ATI/g.