Influence of Age on the Remnant Kidney in Uninephrectomized Rats

Kim, Sang Gyu; Kim, Kwang Sae

Abstract

To investigate the influence of age on the remnant kidney, unilateral nephrectomy was performed in rats at 1week(group N-1), 3weeks(group N-3), 5weeks(group N-5), 7weeks(group N-7). 9weeks(group N-9), and 10weeks(group N-10) of age and sham operation was performed in the control group of rats at the same ages. Proteinuria in spot urine, serum BUN/creatinine, compensatory renal growth and histologic changes were compared with in each group at 32weeks after uninephrectomy. The results were as follows : 1. A compensatory renal growth in nephrectomy group was significantly greater than that in sham operated groups(p <0.001 ) and a compensatory renal growth in prepubertal groups( N-1, 3, 5. 7) was significantly greater than that in postpubertal groups ( N-9, IO) between the nephrectomy groups. 2. In histologic changes, visceral glomerular epithelial proliferation, mesangeal widening and proliferation, obliteration of capillary lumen were more marked in nephrectomy group than sham operated group and group N-1, N-3, N-5, N-7 than in groups N-9, N-10 at week 32. 3. The proteinuria in spot urine was more marked in nephrectomy groups than sham operated groups at week 32 and there was no significant difference in serum BUN/creatinine between nephrectomy group and sham operated groups. It is concluded that in rat, uninephrectomy at young ages leads to more marked compensatory renal growth and histologic change than uninephrectomy in the adult and functionally, proteinuria precedes change of serum BUN and creatinine.