Blood cholesterol profile in guineapigs: Effect of ascorbic acid ingestion on hypercholesterolemia induced by manganese deficiency or overdosage of an anti-thyroid agent in diet

Effects of ascorbic acid ingestion (0.25 g/day) on serum cholesterol and total lipid levels were compared in three hyperlipidemic guineapig models. The first model received a diet rich in atherogenic and thrombogenic agents (e.g. cholesterol, butter-fat, cholic acid, vitamin D₂ etc.). The second (hypothyroid) and third (deficient manganese) models were created by feeding excess propyl-thiouracil (a potent goitrogen) and low-level manganese without added dietary cholesterol. The extreme rapidity with which guineapigs of Wistar strain develop hypercholesterolemia and early atherosclerotic lesions makes them an attractive animal model for studying the early development of atherosclerosis in man.

Decreased serum and tissue cholesterol levels despite more dietary cholesterol and butter-fat indicate that ascorbic acid is a good hypolipidemic/hypocholesterolemic agent. As the lipid-lowering property of ascorbic acid is obliterated due to hypothyroidism, it is most probable that vitamin C may act through the thyroid gland. Interaction with thyroid hormones seems not unlikely for ascorbic acid under physiological conditions. Since ascorbic acid has been suggested to provide protection against atherosclerosis induced by atherogenic/thrombogenic agents and proved incoherent in the face of thyroid dysfunction and manganese deprivation, the precise relation of these effects to lipid metabolism warrants investigation in some other fields.