Abstract
The effects of chronic ethanol ingestion on the rat kidney were studied. Rats were fed a liquid diet containing ethanol for 5 weeks to induce chronic alcoholism. Renal ischemia was introduced by clamping the renal artery and vein either for 10 or 20 min. The glomerular filtration rate (GFR) and the renal blood flow (RBF) were determined by using I125-iothalamate and I131-iodohippurate. In the absence of renal ischemia, there were no significant differences in the renal function between nonalcoholic rats (n = 5) and alcoholic rats (n = 5): 380 ± 30 vs. 403 ± 27 μl/min/100 g body weight (BW) in GFR, and 3.1 ± 0.1 vs. 3.1 ± 0.2 ml/min/100 g BW in RBF. The recovery of GFR measured 2 h following 10-min renal ischemia in both groups was not significantly different; the values returned to 340 ± 40 μl/min/100 g BW (nonalcoholic rats) and 246 ± 22 μl/min/100 g BW (alcoholic rats), respectively. The changes of RBF following 10 min ischemia were also similar in both groups. However, the effects of alcoholism on the renal function became apparent when animals were subjected to more prolonged renal ischemia. In nonalcoholic rats (n = 5), GFR and RBF measured 2 h following 20 min renal ischemia were 245 ± 51 μl/min/100 g BW and 2.5 ± 0.4 ml/min/100 g BW, whereas in alcoholic rats (n = 5) the GFR and RBF were significantly decreased to 93 ± 15 μl/min/100 g BW and 1.1 ± 0.2 ml/min/100 g BW, respectively (p < 0.05). The percent fractional sodium excretion of alcoholic rats (9.11 ± 0.89%) was significantly higher than that of nonalcoholic rats (2.17 ± 0.76%). The histology revealed some renal tubular degeneration in alcoholic rats following 20 min renal ischemia, whereas renal tissue of nonalcoholic rats showed no changes. Our observation demonstrated that the kidney which has been exposed to chronic alcoholism was more susceptible to ischemic insult.