STUDIES ON THE METABOLISM OF ALPHA-LIPOIC ACID IN CHILDHOOD. 3. EFFECT OF DIETARY COMPOSITION AND ANBOLIC STEROID.

Abstract

The effect of dietary composition and anabolic steroid hormone on the lipoic acid metabolism in weaning and mature rats were observed and the following findings were obtained.1. The urinary excretion for 24 hours, and the levels in the serum, liver and kidney of lipoic acid in mature rats were, on an average, 77mμg, 17.5mμg/ml, 2880mμg/g and 2700mμg/g, respectively and the nitrogen contents of the liver and kidney were 29.0 and 31.6mg/g respectively.2. The urinary excretion and the serum level of lipoic acid in the low protein diet group were slightly lower than those in the standard diet group. In such animals, the lipoic acid content in the liver was remarkably decreased in correlation with the decline of nitrogen level.3. The influence of a low protein diet was stronger in the weaning rats than in the mature ones. The lipoic acid level in the liver was decreased to 50% of the normal level.4. The effect of amino acid deficiency of the diet on the content of lipoic acid in the liver was examined and the influence of tryptophan deficiency was the strongest, followed by that of lysine deficiency.5. The effect of the anabolic steroid hormone on the weight gain, serum protein concentration, urinary excretion of lipoic acid, serum lipoic acid level, weight of the liver, kidney, or testicle, and nitrogen and lipoic acid contents of these tissues under several different conditions of the diet in rats were investigated.The anabolic effect on nitrogen metabolism and the influence on the lipoic acid metabolism by this type of hormone were most remarkable when the rats were fed at first the low protein diet and then that with a sufficient quantity of protein. On the contrary, the catabolic effect of 19-norandrosterone phenylpropionate was observed in the rats fed a sufficient or low protein diet.