INDUCTION OF HSP72 IN RAT-LIVER BY CHRONIC ETHANOL-CONSUMPTION COMBINED WITH EXERCISE - ASSOCIATION WITH THE PREVENTION OF ETHANOL-INDUCED FATTY LIVER BY EXERCISE

Ethanol-induced fatty liver in rats was attenuated by repeated running exercise, and the protective effect of exercise was associated with t he synergistic expression of heat shock proteins (HSP72). Rats were pl aced in four groups of six. The two ethanol-fed groups of rats receive d a liquid diet (Lieber-DeCarli formulation) in which 36% of the calor ies were derived from ethanol. One group remained sedentary (S/E), whe reas the other was trained to run on a rodent treadmill at a speed of 27 m/min, 1 hr/day, 5 days/week, for 7 weeks (R/E). Two other groups-o ne exercised as previously mentioned (R/C) and one sedentary (S/C)-rec eived control-liquid diets in which the ethanol was isocalorically sub stituted with a dextran/maltose mixture. The degree of fatty infiltrat ion in liver sections stained with hematoxylin and eosin was graded on a 0-4 scale and the data analyzed by ANOVA on ranks. Ethanol signific antly induced fatty infiltration in the S/E group, whereas fatty infil tration in the livers of the R/E group was not different from the S/C group. Electrophoresis and Western blotting of liver homogenates demon strated that HSP72 was not expressed in either the S/C or S/E groups a nd was only slightly expressed in the R/C group. The combination of ex ercise and ethanol, however, resulted in an elevated expression of HSP 72 in the R/E group. The content of HSP73 was unaffected by any treatm ent.