Experimental arteriosclerosis in Rhesus monkeys induced by multiple risk factors: cholesterol, vitamin D, and nictotine.

Forty-four rhesus monkeys were given various regimens involving three vasotoxic factors: dietary hypercholesteremia, hypervitaminosis D2 and nicotinism for period ranging from 14 to 62 weeks. When administered singly, no or only early disease was observed. The combined three "risk factor" group demonstrated the most impressive arteriosclerosis. Major arteriosclerotic changes: fat, calcium and mensenchyme of thirty standardized segments of aorta, coronary and limb arteries of all monkeys were graded according to a standardized system. Statistical analysis revealed that the total arteriosclerotic scores of the three vasotoxic factor group was significantly greater than those of any other group and that this was the only group with significant coronary arteriosclerosis as well as complicated lesions such as thrombosis or occlusion of arterial luminae of the extremities. A lowering of the vitamin D2 dosage, resulting in a lengthening of the survival time of animals which should allow sufficient time for complicated disease to develop, is recommended for future studies.