Rat Liver Alcohol Dehydrogenase Activity: Effects of Growth Hormone and Hypophysectomy*

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Abstract
Previously demonstrated increases in liver alcohol dehydrogenase in experimental uremia and after stress in the rat may be mediated by hormonal changes found in these conditions. In this study, the effects of corticosteroids, GH, adrenalectomy, and hypophysectomy on the activity of liver alcohol dehydrogenase in the rat were determined. Neither the daily administration of hydrocortisone, corticosterone, or corticotropin for 6 days nor adrenalectomy had any effect on the enzyme activity. Bovine GH, administered in doses of 0.02, 0.2, 1.0, and 4 mg/100 g BW-day for 6.5 days, resulted in increases in liver alcohol dehydrogenase. A maximum increase in the enzyme activity was found after the administration of the low dose of 0.02 mg/100 g BW-day. Plasma GH was found to be elevated in rats with increased liver alcohol dehydrogenase due to uremia or after repeated stress induced by immobilization; hence, GH may play a role in the elevation of the enzyme activity in these conditions. However, hypophysectoy was found also to increase the activity of the enzyme, and the administration of GH to the hypophysectomized animals suppressed the enhanced enzyme activity. Maximum suppression was obtained after the administration of a dose of 1.0 mg/100 g BW • day. These results indicate that liver alcohol dehydrogenase activity is affected by GH as well as by other unknown factors which are altered by hypophysectomy.