Abstract
A study was conducted on the distribution of lipids in old rats aRd activity of essential fatty acids when protein anabolic steroid is presumably very scarce. Next the relationship between protein anabolic steroid and lipids, especially essential fatty acids, was observed as protein anabolic steroid was administered to old rats.
1) Total lipids, total cholesterol and essential fatty acids in the adrenals, liver and serum were always higher in old than in young rats, especially, 1inoleic acid and arachidonic acid in the adrenals.
2) When protein anabolic steroid was administered to old rats, the adrenal weight tended to decrease, and the weight of the M. levator ani increased slightly. These changes, however, were much less than in young rats.
3) Even when protein anabolic steroid was administered to old rats, the total lipids in the adrenals, liver and serum did not decrease, but arachidonic acid in the adrenals, showed a definite decrease. In the serum, however, it tended to increase. In the kidney, M. levator ani and diaphragm, arachidonic acid increased but less so than in young rats. These observations suggest that aging reduces the ability to use arachidonic acid in the promotion of protein production in tissues.
4) The annount of fat in the rat body increases in old age, because of both inhibition of fat catabolism and the reduction of utilization of lipids tissue formation. Thus, it is readily seen that the utilization of essential fatty acids, which is a constant element, falls with age.
