Selective increase of cyclooxygenase-2 expression in a model of
renal ablation.
Wang, Jun-Ling, Hui-Fang Cheng, Ming-Zhi Zhang, James. A. McKanna and
Raymond C. Harris.
George M. O'Brien Kidney and Urologic Diseases Center and 1Division
of Nephrology, Department of Medicine, 2Department of Cell Biology,
Vanderbilt University School of Medicine, Nashville, TN 37232
APStracts 5:0127F, 1998.
Previous studies have suggested a possible role for prostaglandins in
mediating alterations in nephron structure and function ensuing after
renal ablation. Two isoforms of cyclooxygenase (COX) have been
described- constitutive (COX-1) and inducible (COX-2). We examined
expression of these isoforms following subtotal renal ablation (5/6
ablation) (RA) in rats. In renal cortex, COX-2 mRNA and
immunoreactive protein (IP) increased progressively compared to sham
-operated litter mates. In contrast, there were no significant changes
in COX-1 mRNA expression. In normal kidney, cortical COX-1 IP was
immunolocalized predominantly to mesangial cells and collecting
tubules, while COX-2 IP was found in a subset of cTALH cells in the
region of the macula densa (MD). Following RA, significantly
increased COX-2 IP was detected in the macula densa and surrounding
cTALH cells. In addition, fainter irCOX-2 was detected in scattered
visceral epithelial cells and mesangial cells of the glomerulus.
Immunoblotting of isolated glomeruli demonstrated a selective
increase of glomerular irCOX-2 expression following RA. No change of
COX-1 expression was seen.
Received 18 December 1997; accepted in final form 2 July 1998.
APS Manuscript Number F399-7.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 21 September 1998