Changes in the lipid composition of rat liver mitochondria and microsomes and in heart mitochondria after swimming
Radeva-Domuschieva, D.; Balevska, P.; Russanov, E.
Acta Physiologica et Pharmacologica Bulgarica 4(1): 55-61
1978
ISSN/ISBN: 0323-9950 PMID: 726917 Document Number: 134815
The content of total lipids, phospholipids and phosphatidylcholine (PC) and phosphatidylethanolamine (PE) was determined in liver mitochondria and microsomes, and heart mitochondria isolated from rats after exhaustive swimming. Muscle work caused an increase in the total lipid content and a decrease of phospholipids mainly of PE in liver mitochondria while it reduces PC and PE in heart mitochondria. The PC/PE ratio in liver mitochondria altered from 1:1 to 2:1 after swimming. In heart mitochondria, it remained at the control level. After swimming, the content of total lipids increased in the liver microsomes, while phospholipids decreased. Both PC and PE levels were lowered, their ratio remaining constant (2:1). The higher total lipid content is explained by the increase in nonpolar lipids and mainly in free fatty acid content. Changes established in phospholipid composition of microsomes correlating to those of mitochondria suggest that the rate of phospholipid synthesis in endoplasmic reticulum is lowered during work. This is due to the increased consumption of ATP at muscle contraction. The results may account for the previously reported changes in the liver and heart mitochondrial functions and enzyme activities after exhaustive swimming. After a 22-h rest period the levels of mitochondrial PE and PC returned to normal in both organs.