Abstract
The immunolocalization of S100βlike protein was investigated in the kidney of saltwater fishes (Dicentrarchus labrax; Coris julis; Serranus cabrilla; Scorpaena porcus), amphibia (Rana aesculenta), reptiles (Lacerta viridis), and aves (Gallus domesticus; Strutio camelus). S100βlike immunoreactivity was detected in the juxtaglomerular cells of all saltwater fishes studied. No immunoreactivity was observed in other tracts of the nephron or in the interstitial tissue. In frog kidney, S100βlike immunoreactive cells were localized in the proximal tubule, singly distributed or placed side by side in clusters of two or three cells. S100βlike immunoreactive cells were distributed in the distal and in the collecting tubules in lizard, chicken, and ostrich kidney. In the distal tubule of lizard kidney, S100βlike immunoreactive cells were numerous and uniformly distributed. In lizard collecting tubules, S100βlike immunoreactive cells showed less intense immunoreactivity than in the distal tubule, except for a cluster of cells at the junction with the initial collecting duct. In chicken and ostrich kidney, S100βlike immunoreactive cells of the distal tubules were closely packed together. In the collecting tubules, S100βlike immunoreactive cells were alternate to negative cells. These results indicate the high conservation degree of S100 proteins through phylogenesis and suggest a functional role for these proteins in the vertebrate kidney. Microsc. Res. Tech. 60:652β657, 2003. Β© 2003 WileyβLiss, Inc.