Carvedilol Ameliorates Early Diabetic Nephropathy in Streptozotocin-Induced Diabetic Rats
Figure 3
Effect of carvedilol (1 and 10 mg/kg/day) on immunohistochemical localization of cyclooxygenase-2 (COX-2) in the renal tissue of streptozotocin-induced early diabetic nephropathy in rats (100x). (a) Kidney tissue of nondiabetic rat; notice constitutional expression of COX-2 in the cytoplasm of macula densa cells (arrows) while tubular epithelial cells show negative signals (arrowhead). (b) Kidney tissue of diabetic rat showing increase of COX-2 expression in macula densa cells; notice that both the cytoplasm and the nucleus of macula densa cells are positive (arrows). Some of the tubular epithelial cells have cytoplasmic positive signals for COX-2 (arrowheads). (c) Kidney tissue after treatment with 1 mg carvedilol; COX-2 expression in the macula densa cells decreased and confined to the cytoplasm only (arrows) while tubular epithelial cells are still showing positive COX-2 expression (arrowhead). (d) Kidney tissue from diabetic rat treated with 10 mg carvedilol; notice normal level of COX-2 expression in the cytoplasm of macula densa cells (arrows) with negative expression in the tubular epithelial cells (arrowheads).
