Lipid composition of brown adipose tissue mitochondria and microsomes in hyperthyroid rats

Abstract

1. 1. The effects of triiodothyronine on the lipid composition of rat brown adipose tissue (BAT) mitochondria and microsomes was investigated by high performance liquid chromatography (HPLC). 2. 2. An increase of about 20% was noted in mitochondrial cholesterol and phospholipids, while a decrease of about 20% for both total cholesterol and phospholipids was observed in microsomes from hyperthyroid rats. 3. 3. The BAT phospholipid composition was altered significantly in mitochondria from T 3-treated rats with an increase (41%) of cardiolipin and a decrease (18%) in phosphatidylcholine. 4. 4. In microsomes, a decrease by 25% in phosphatidylinositol was accompanied by a similar additional percentage increase in phosphatidylethanolamine. 5. 5. Important alterations in the fatty acid pattern were found in mitochondrial neutral lipids.