New model of atherosclerosis in sand rats subjected to a high cholesterol diet and vitamin D2.

In order to defeat the atheroresistance in sand rats, 25 animals were given a high cholesterol diet for 45 days, which was then associated with oral treatment with vitamin D2 2000 IU/day for a further 45 days. At days 0, 45 and 90, plasma parameters, and aortic and heart morphology were examined. Results showed at D45 hypercholesterolaemia, increased plasma LDL and VLDL cholesterol, oxidized LDL, triglycerides, free fatty acids (FFA) and calcium levels and moderate hyperinsulinaemia. At D90, plasma-oxidized LDL and FFA were more enhanced, whereas calcium level was reduced. Development of hyperglycaemia was associated with hyperinsulinaemia and insulin resistance. The vitamin D2 administration induced advanced lesions, represented by the degenerescence of elastic lamina, smooth muscle cell proliferation and lipid calcic plaque at an ulcerated stage in most cases. The ischaemic effects were represented by acute myocardial infarction. The potential of the sand rat to develop atherosclerotic lesions at different stages opens the field to therapeutic tests of new anti-atherogenic agents.