Long-term melatonin administration increases polyunsaturated fatty acid percentage in plasma lipids of hypercholesterolemic rats

• Published in: Journal of pineal research Vol. 32; no. 3; pp. 179 - 186
• Main Authors: Pita, María L., Hoyos, Marta, Martin-Lacave, Inés, Osuna, Carmen, Fernández-Santos, Jose M., Guerrero, Juan M.
• Format: Journal Article
• Language: English
• Published: Oxford UK Blackwell Publishing Ltd 01.04.2002; Blackwell
• Subjects: Animals; Aorta - drug effects; Aorta - pathology; atherosclerosis; Biological and medical sciences; cholesterol; Cholesterol, Dietary - pharmacology; Erythrocyte Membrane - drug effects; Erythrocyte Membrane - metabolism; fatty acids; Fatty Acids, Unsaturated - chemistry; Fatty Acids, Unsaturated - metabolism; Fundamental and applied biological sciences. Psychology; Hormones and neuropeptides. Regulation; Hypercholesterolemia - blood; Hypercholesterolemia - drug therapy; Hypothalamus. Hypophysis. Epiphysis. Urophysis; Lipids - blood; Lipids - chemistry; Liver - drug effects; Liver - metabolism; Liver - pathology; Male; melatonin; Melatonin - administration & dosage; pineal; Rats; Rats, Wistar; Vertebrates: endocrinology; Melatonin; Rat; Rodentia; Polyunsaturated fatty acid; Cardiovascular disease; Metabolic diseases; Lipids; Hyperlipoproteinemia; Cholesterol; Feeding; Vascular disease; Vertebrata; Mammalia; Hypercholesterolemia; Diet; Atherosclerosis; Dyslipemia; Pineal hormone
• ISSN: 0742-3098; 1600-079X
• DOI: 10.1034/j.1600-079x.2002.1o851.x

This study was designed to investigate the effect of melatonin on the fatty acid composition of plasma and tissue lipids. Melatonin administration to rats fed with a standard diet only increased long‐chain n‐6 polyunsaturated fatty acids (PUFA) in total plasma lipids and liver phospholipids but induced significant changes in hypercholesterolemic rats. In plasma, palmitoleic and oleic acids increased and n‐6 and n‐3 PUFA decreased in hypercholesterolemic rats; theses changes were reversed by melatonin administration. The analysis of lipid fractions revealed that only the cholesteryl ester fraction was affected by melatonin. Histological studies of the carotid artery intima revealed the appearance, in hypercholesterolemic rats, of fatty streaks produced by a mass of foam cells covered by the endothelium and by a thin layer of mononucleated cells. These changes were prevented by melatonin. We conclude that long‐term melatonin administration modifies the fatty acid composition of rat plasma and liver lipids and ameliorates the arterial fatty infiltration induced by cholesterol.