Aliphatic wax alcohols and other lipids in atheromata and arterial tissues of cetaceans

Abstract

1. 1. Detailed lipid analyses were carried out on normal and atheromatous aterial tissue from a sperm whale ( Physeter macrocephalus), a pilot whale ( Globicephalus malaena) and a killer whale ( Orcinus orca). 2. 2. Fatty acids from plasma and arterial tissues contained little linoleic acid (< 4 per cent) and a sizable concentration of eicosapentenoic acid. 3. 3. Wax alcohols were present as esters and free alcohols in normal and atheromatous tissues. Wax alcohols having chain lenghts of sixteen and eighteen carbons predominated. Relative abundance of dominant esterified and free wax alcohols from the same tissue were similar to each other. 4. 4. Concentrations of cholesterol and total lipid in plasma of the killer whale were 160 and 619 mg per cent respectively. Ratio of hig-density lipoprotein (> 1·063) to low-density lipoprotein (<1·063) in plasma-serum mixture was 4:1. 5. 5. In the aortic lesions from the sperm whale and pilot whale, lipid pattern and fatty-acid composition of lipid components were virtually identical with those of their underlying and surrounding tissues. 6. 6. In the killer whale a fibrous aortic plaque contained a higher concentration of wax + sterol ester than normal aortic tissue. A much larger difference in the concentration of total lipid and of wax + sterol ester was seen in a fatty coronary atheroma of the killer whale as opposed to normal coronary tissue. 7. 7. Plasma from this killer whale was similar to fibrous aortic plaque, normal aortic tissue and fatty coronary atheroma in the relative abundances of most of the fatty acids of wax + sterol ester. This result suggested plasma as a principal source of these arterial tissue wax + sterol esters.