Green Tea Attenuates Oxidative Stress and Downregulates the Expression of Angiotensin II AT1 Receptor in Renal and Hepatic Tissues of Streptozotocin-Induced Diabetic Rats
Figure 5
Immunohistochemical localization of AT1 receptor expression in the renal cortex of normal control (a), diabetic control (b), and green-tea-treated diabetic (c) rats. Renal sections were treated with the polyclonal anti-AT1 receptor antibody and counterstained with hematoxylin as detailed in Materials and Methods. In (a), positive labeling was detected with marked intensity in Bowman’s capsule and distal convoluted tubules epithelia, but was of moderate intensity among glomeruli and uniformly diffused in proximal convoluted tubules epithelia. In (b), the labeling was maintained at a high intensity in the epithelial lining of the distal convoluted tubules, but was markedly reduced in Bowman’s capsule and glomeruli as opposed to its enhanced intensity in the apical side of the proximal convoluted tubules epithelia. In (c), the labeling was almost lacking in Bowman’s capsule and glomeruli and appeared as faded patches at the basolateral side of some of the proximal convoluted tubules epithelia, but was of persistent high intensity confined to the distal convoluted tubules epithelia. No specific labeling was observed in renal sections labeled with the anti-AT1 antibody preabsorbed with an AT1 octapeptide/BSA complex (d). Images are representative of four different samples for each rat group. DCT: distal convoluted tubule, G: glomerulus, and PCT: proximal convoluted tubule. , ×100.
