ダイコクネズミにおけるDimethylnitrosamineおよびBasic Lead Acetateによる実験的腎腫瘍発生におよぼす偏腎摘除の影響

Abstract

Previous studies showed that unilateral nephrectomy promoted the induction of kidney tumors by dimethylnitrosamine (DMN). In the present investigation, the influence of unilateral nephrectomy on the production of kidney tumors in rats treated with DMN and basic lead acetate (BLA) was studied. Wistar strain male rats were .divided into the following 7 groups: (1) nephrectomy plus DMN followed by BLA, (2) nephrectomy plus DMN, (3) nephrectomy plus BLA, (4) sham operation plus DMN followed by BLA, (5) sham operation plus DMN, (6) sham operation plus BLA, (7) nephrectomy alone. The animals were given either a diet containing 500ppm DMN or the basal diet for 2 weeks followed by a 1.5% BLA-containing diet or the basal diet for about 22 weeks, and were sacrificed about 24 weeks after the experiment. All the rats treated with unilateral nephrectomy plus DMN and BLA developed kidney tumors. A comparable group of sham-operation rats showed a 75.096 incidence of kidney tumors. Two (18.2%) of the rats treated with unilateral nephrectomy plus BLA developed kidney tumors. In contrast, no rats of sham operation plus BLA showed the development of kidney tumors. These results indicate that unilateral nephrectomy accelerated the development of rat kidney tumors induced with both DMN and BLA. Histologically, the synergistic effects were found in the kidney tumorigenesis of rats treated with DMN and BLA.