Changes in the concentration and fatty acid composition of phospholipids in rat skeletal muscle during postnatal development.

Abstract

AbstractRat skeletal muscle was analysed at different ages, from birth to 90 days, for its concentration of phospholipids and individual phosphoglycerides, and for the fatty acid pattern of cardiolipin, choline phosphoglyceride (CPG), ethanolamine phosphoglyceride (EPG), inositol phospho‐glyceride and serine phosphoglyceride (SPG). The concentration of phospholipids was found to increase between birth and two weeks of age, after which it decreased slightly to 14 μmol/g fresh weight at the age of 90 days. The relative amount of CPG and EPG varied but little with age, while that of cardiolipin increased to three times its original value. The concentration of polyenoic acids increased with age in all phosphoglycerides except SPG. The concentration of the sum of the fatty acids of the linoleic acid series in CPG increased rapidly during the first weeks of life, while that of the linolenic acid series increased throughout the period studied. In EPG the concentration of the sum of the fatty acids of the linolenic acid series increased, while that of the linoleic acids decreased and the concentration of linoleic acid in cardiolipin increased. In the muscles of 90‐day‐old rats, the fatty acid pattern of cardiolipin showed a high level of linoleic acid and no fatty acids of the linolenic acid series. The fatty acid pattern of CPG was characterized by rather high levels of both linoleic and arachidonic acids and that of EPG by a high concentration of the fatty acids of the linolenic acid series.