Effects of melatonin on genetic hypercholesterolemia in rats.

Administration of the pineal hormone melatonin to genetically hypercholesterolemic rats resulted in a decrease in plasma cholesterol levels and in an improvement of fatty changes of the liver. Thus, the antihyperlipemic effect of melatonin, which was first discovered in hypercholesterolemia produced by short- or long-term administration of glucocorticoids, has now been proved to be rather universal and not simply anti-glucocorticoidal. The mechanism of the decrease of plasma cholesterol levels remains unknown. It was also found that the pathogenesis of this so-called genetic hypercholesterolemia in rats involved biochemical nephrotic changes and histopathological changes in the kidney.