Cell proliferation, apoptosis, Bcl-2 and Bax expression in obstructed opossum early metanephroi

Purpose: Complete ureteral obstruction (CUTO) in the fetal. kidney induces tubular and glomerular cysts, interstitial fibrosis, and halts renal develo pment. Previous studies have shown that apoptosis is a predominant mechanis m in the chronically injured kidney following obstruction, but the precise cellular and molecular mechanisms are poorly understood. Materials and Methods: We have used CUTO in opossum pups with early metanep hric kidneys, sacrificed at two weeks, to evaluate the role of cell prolife ration, apoptosis and apoptosis regulating genes, Bcl-2 and Pax. Results: Obstructed fetal kidneys demonstrate high apoptosis in the renal p elvis and tubulointerstitium, compared with sham operated animals. Apoptosi s is accompanied by statistically significant increased cell proliferation in the interstitium but not in tubules. Apoptosis in the tubules is accompa nied by increased Bar and decreased Bcl-2 staining. In the nephrogenic zone apoptosis is increased, even though it is not statistically significant. B cl-2 and Pax in the nephrogenic zone are unchanged compared with sham, but cell proliferation is increased. Conclusions: We suggest that abnormal patterns of cell kinetics may contrib ute to disease pathogenesis in the obstructed fetal kidney.