Degeneration of aortic smooth muscle cells in swine fed excess vitamin D3.

Twenty-eight weanling swine were divided into two groups and fed a basal ration of corn and soybean meal or one containing a high fat and cholesterol supplement. One subgroup of each received 220,000 IU of vitamin D3 per kilogram. Grossly normal areas of the distal abdominal aorta were used for quantitative comparison of degenerated smooth muscle cells by electron microscopical cell counts. Degeneration was classified into rarefaction, condensation, and frequency per 100 nucleated cells. The frequency of dead cells was demonstrable between the swine fed excess vitamin D3 with or without high fat and cholesterol and those fed the basal ration alone, or frequencies of 7.9, 7.4, and 5.6 at 3 months of age (P less than .05) and 7.3, 6.2, and 5.1 at 6 months (P less than .05), respectively. No significant difference was demonstrable between the swine fed high fat and cholesterol without excess vitamin D3 and those fed the basal ration alone, or frequencies of 5.7 and 5.6 at 3 months of age and 5.5 and 5.1 at 6 months.