Clinical profile of a 4-year primate atherosclerosis model

Twelve male M. fascicularis monkeys were divided into two groups of 6 animals each. One group (BASAL) was fed a diet containing 24% protein, 38% carbohydrate and 20% fat, while the other group (ATHER) received an identical diet with the addition of 4.08 g/kg diet cholesterol. The animals were studied over a 4-year period. Blood samples were regularly collected, ECGs taken and carotid artery status evaluated by duplex ultrasound scanning. Lipid xanthomas were monitored by visual inspection. The ATHER group experienced a rapid and sustained rise in serum total cholesterol, concomitant with depression of HDL-cholesterol. In general, triglycerides were significantly higher in ATHER animals. Routine clinical analysis revealed lower hematocrit and hemoglobin, and elevated BUN and alkaline phosphatase in the treated group. Lipid xanthomas were detected early in the ATHER animals, progressing until infiltration was evident on the entire body surface. There were no differences in ECGs between the groups. At approximately 17 months posttreatment, stenosis was apparent in the carotid arteries of treated animals, rising to an average of 90% at study termination. These results indicate that diet-induced carotid atherosclerosis can be monitored non-invasively in the primate with minimum risk to the animal.