A kinetic study of the glomerular cells of developing and mature rat kidneys using an anti-bromodeoxyuridine monoclonal antibody.
Newborn and mature Wistar rats received a single intraperitoneal injection of 5 bromo-2'-deoxyuridine (BrdU), a DNA precursor, to assess cellular proliferation by labeling S-phase cells. For immunohistochemical analysis, paraffin sections were prepared two hours after BrdU injection. The various stages of development of the glomeruli were observed within each newborn rat. The most primitive glomeruli were found close to the renal capsule, with progressively more mature glomeruli appearing in the deep renal cortex. BrdU-positive nuclei were frequently detected in the epithelia of nephrogenic vesicles, S-shaped vesicles and ureteral buds. When the capillaries invaded the S-shaped vesicles, the developing glomerular basement membrane was recognizable. In this and more mature stages of the glomeruli, presumptive podocytes no longer showed BrdU-positive nuclei, but they were easily detected in the mesangial and endothelial cells of the glomerular tufts. The mean labeling index of the glomerular tuft cells of mature rats was approximately 0.54%. The majority of labeled cells in the glomerular tufts were endothelial cells. Mesangial cells had a low labeling index. Podocytes revealed no evidence of proliferation. The labeling index of Bowman's epithelial cells, however, was approximately 0.71%, higher than that of the tuft cells. These findings may contribute to a better understanding of the mechanisms of cellular interplay within the glomeruli.
Sasaki
T
T
Department of Internal Medicine, Kawasaki Medical School, Okayama, Japan.
Osawa
G
G
D000818:Animals; D000831:Animals, Newborn; D000911:Antibodies, Monoclonal; D001973:Bromodeoxyuridine / Q000276:immunology; D005260:Female; D007678:Kidney Glomerulus / Q000166:cytology* / Q000254:growth & development; D008297:Male; D051381:Rats; D017208:Rats, Wistar
D000911:Antibodies, Monoclonal; D001973:Bromodeoxyuridine