Hepatocellular Vacuolization in Rabbits: Effects of Feed Restriction, Orchiectomy and Ovariectomy

Abstract

Previous studies have reported that striking variations in hepatocellular vacuolization occurs in rabbits and the magnitude of vacuolization correlated independently with weight and sex. The current study evaluated the effects of feed restriction and gonadectomy on this hepatocellular vacuolization. For 28 days, rabbits were fed either ad libitum (ad lib group), 100% of the National Research Council's recommended feed intake required for growth (100% group), or 50% of the NRC recommended feed intake required for growth (50% group). Feed consumption, weight gain, final body weight, absolute liver weight, and relative liver weight were not significantly different between the ad lib and 100% groups. Values for these parameters for both groups were significantly greater than for the 50% group. Rabbits in the 50% group had significantly less hepatocellular vacuolization than rabbits in the 100% group. Hepatocellular vacuolization in the 100% group did not differ from rabbits fed ad libitum. Hepatocellular vacuolization in the ad lib group was greater than in the 50% group but this difference was not significant. Ovariectomy and orchiectomy did not significantly alter hepatocellular vacuolization in either female or male rabbits, respectively, that were fed ad libitum for 28 days. However, intact females had significantly greater hepatocellular vacuolization than either intact or orchiectomized males. Conversely, hepatocellular vacuolization in ovariectomized females was not significantly different from that in intact and orchiectomized males. There were no significant differences in feed consumption, weight gain, final body weight, and absolute and relative liver weights among these intact and gonadectomized groups. Results of these studies indicate feed consumption can affect the degree of hepatocellular vacuolization in rabbits. In addition, intact female rabbits have greater hepatocellular vacuolization than males. This difference is reduced by ovariectomy.