Total lipid, lipid phosphorus and phospholipid class distribution were determined for heart and skeletal muscles from five vertebrates (human, bovine, rat, mouse and frog) and skeletal muscles from four invertebrates (lobster, abalone, scallop and sea urchin). The precision of the analytical method [separation by two-dimensional thin layer chromatography (TLC) and phosphorus analysis of spots] was demonstrated by small values for standard deviations. Accuracy of spot identification and analytical values was insured by comparison with results obtained by TLC of triethylaminoethyl cellulose column chromatographic fractions. Values for total lipid, total phospholipid and phospholipid class distribution of heart and skeletal muscles from the five vertebrate species showed essentially the same variability observed for the same organ from different animals of one species (rat). The data indicate that, among vertebrates there is little or no variability for phospholipid class distribution in muscle membranes in agreement with data for other organs and subcellular particulates presented in other reports. Invertebrate skeletal muscles were found to differ qualitatively and/or quantitatively from those of vertebrates. In one species (sea urchin), ceramide phosphorylethanolamine was the only sphingolipid, sphingomyelin characteristic of vertebrates being absent. In two species (abalone and scallop) ceramide aminoethylphosphonate was present and sphingomyelin was absent. In one (lobster), sphingomyelin was the only sphingolipid. Quantitatively, higher levels of sphingolipid and phosphatidyl serine and lower levels of phosphatidyl inositol were found in invertebrate skeletal muscle. The significance of the data is discussed in relation to subcellular particulate lipid class composition. © 1969 The American Oil Chemists' Society.
