Cholesterol-induced atherosclerosis in the rabbit: effect of dimethyl sulfoxide on existing lesions

Earlier studies have established that the analgesic and anti-inflammatory compound, dimethyl sulfoxide (DMSO), was effective in preventing atherosclerosis in cholesterol-fed rabbits. In the present studies, the effect of DMSO on existing atherosclerotic lesions in cholesterol-fed rabbits was investigated. Rabbits were placed on an atherogenic diet containing 1% cholesterol for a period of 10 weeks. At the end of the 10-week period, the rabbits were randomly divided into two groups: one group was placed on a control diet consisting of regular rabbit chow for an additional 12-week period, whereas the remaining group was continued on the atherogenic diet. During this period half of the rabbits in each of these groups were treated with DMSO (approximately 5 g/kg) which was included in their drinking water. Food consumption and fluid intakes were monitored daily and body weights at weekly intervals. Total serum cholesterol levels were measured at periodic intervals. Lipid deposits in the eye which accompany atherosclerosis were examined before and at 12 weeks after institution of the new dietary regimens. At the end of 12 weeks, all rabbits were killed and the thoracic aortas were examined for changes in the extent of atherosclerosis. Food consumption and body weight increased in rabbits on the control diet and in those treated with DMSO. Those maintained on the atherogenic diet showed little change in food intake or body weight. Fluid intake was significantly elevated in all rabbits placed on DMSO. Serum cholesterol levels returned to normal in all rabbits on the control diet. Serum cholesterol levels remained unchanged in rabbits kept on the atherogenic diet alone.(ABSTRACT TRUNCATED AT 250 WORDS)