Fig. 4

(Short title) Renal localization of COX-1 and COX-2: (Detailed legend) COX-1 (Fig. 4.a to d, 4 top panels) and COX-2 (Fig. 4.e to h, 4 bottom panels) in the normal feline kidney. Results from 21 cats (ten young and 11 old). Magnification × 400. ⋆ denotes the macula densa, ⋆⋆ denotes the glomerulus, + denotes the afferent arteriole, # denotes the distal tubule, ## denotes the proximal tubule, * denotes the thin limb of the loop of Henle, ** denotes the thick limb of the loop of Henle, *** denotes the collecting duct and ⇽ denotes the medullary interstitial cells. a to d: The most intense expression of COX-1 was found in the thick limb of the loop of Henle (c) followed by the collecting duct (d), the distal tubule (b), the thin limb of the loop of Henle (c) and the macula densa (a), respectively. In the proximal tubule (b), the glomerulus (a) and the afferent arteriole (a), COX-1 expression was very weak to absent. h: The strongest COX-2 expression was found in the macula densa (e) followed by the thin loop of Henle (g), the thick limb of the loop of Henle (g), the proximal tubule (f), the medullary interstitial cells (g) and the collecting duct (h), respectively. In the distal tubule (f), the glomerulus (e) and the afferent arteriole (e), COX-2 was either expressed very weakly or was absent