Glomerular cell proliferation and apoptosis in uninephrectomized spontaneously hypertensive rats

We studied renal function, glomerular cell proliferation and apoptosis for three months after uninephrectomy (UNX) in young, male, spontaneously hypertensive rats (SHR). Apoptosis was assessed by in situ dUTP biotin nick-end labeling method (TUNEL) and by propidium iodide staining. Proliferation rate was determined by immunohistochemistry to proliferating cell nuclear antigen (PCNA). Glomerular bcl-2 expression was assessed by Northern blot analysis. Our results indicate a parallel increase in proliferation and in apoptotic rates in glomerular cells from the first to the second month after UNX. In the third month after UNX, PCNA-labeled cell number continues increasing, whereas TUNEL-labeled cells did not increase. Bcl-2 expression was negative in the first and second months and increased in the third month. Glomerular size and proteinuria increased progressively along the three months of follow-up. Our observations demonstrate a different profile of cell proliferation and apoptosis during the genesis of early glomerular damage in UNX-SHR.