Effect of Cortisone on the Lipids of Bone Matrix in the Rat. ∗

Abstract

Recent studies have shown that lipids are present in significant amounts in the matrix of bone and that they vary upon the administration of exogenous agents which alter the state of mineralization of bone (1,2). Because of the known effect of cortisone on bone(3,4) and because cortisone is known to alter systemic lipid metabolism (5) the following experiments were carried out in order to determine whether the lipids of bone matrix are changed after cortisone administration and whether the osseous changes brought about by cortisone can be related to lipid changes.

Material and methods. 150 g male R.V.H. strain rats were divided into 4 groups of 10 each, as follows: (1) control, (2) adrenalect-omized, (3) cortisone treated, and (4) ad-renalectomized and cortisone treated.

The adrenal glands of the rats from Groups 2 and 4 were removed under light ether anaesthesia through a posterior approach. One-half of Groups 1 and 3 were subjected to a false operation in which all steps were carried out except removal of the gland. The remainder of the animals of these groups served as an absolute control.

Six hours after operation 2 mg of cortisone acetate per .2 ml (Cortone, Merck, Sharp Dohne Ltd.) per 100 g body weight was injected subcutaneously to Groups 3 and 4. The same amount of the suspension base was given to the rats of Groups 1 and 2. Injections were given every day at 24-hour intervals for 10 days. Each cage of experimental animals consisted of 5 rats. They were allowed to eat Purina Labena and to drink tap water ad libitum except for the rats of Group 2, to which 1% NaCl solution was given. Body weight, and food and water consumption per 24 hours were recorded.