Immunohistochemical Distribution of COX-1 and COX-2 in the Renal Tissue of Pubere Rats Treated With Capsaicin

Abstract

The objective of this study was to investigate the effects of capsaicin on the renal distribution of cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) in pubere rats. The expression of the 2 enzymes was analyzed using immunohistochemistry in 50 days old rats daily treated with capsaicin (1 mg/kg, subcutaneously) diluted in 10% ethanol, 1% Tween 20 and 80% distilled water for one week, as well as in sham rats (only injected with the vehicle) and in not injected control rats (n = 10 in each group). Weight growth was significantly deleted in the treated rats but no kidney damage was evidenced by conventional histology. The COX-1 and COX-2 localisations were similar in all rats but the COX-2 expression intensity was markedly depressed in the proximal and distal tubules, macula densa and loops of Henle from the capsaicin treated rats whereas the COX-1 expression appeared increased in proximal tubules compared to the sham and control rodents. These results demonstrate that capsaicin which is already known to affect gastro-intestinal, cardiovascular and respiratory systems, also interfere with the expression of cyclooxygenases in kidney in rats.