Effect of vasectomy on humoral and cell-mediated immunity in monkeys with experimentally induced atherosclerosis

The development of humoral and cell-mediated immune responses and circulating immune complexes following vasectomy were studied in rhesus monkeys fed a high cholesterol (atherogenic) diet. Four groups of monkeys were studied: (i) sham-vasectomized males fed a normal stock diet, (ii) sham-vasectomized males fed an atherogenic diet, (iii) vasectomized males fed a normal stock diet, and (iv) vasectomized males fed an atherogenic diet. Monkeys were observed for a period of 1.5 years. Sperm agglutinins and immobilizins in serum were detected in 100 and 60%, respectively, of vasectomized monkeys fed stock diet. In contrast, 60% of vasectomized monkeys fed an atherogenic diet showed agglutinins in their sera and only 20% exhibited immobilizins. The sensitization of lymphocytes by seminal plasma antigens was of a lower order in vasectomized monkeys fed an atherogenic diet as compared to those maintained on a stock diet. Circulating immune complexes (CIC) were present in both the groups of vasectomized monkeys but the level was higher in animals fed an atherogenic diet. The aortic atherosclerosis score was increased significantly in vasectomized monkeys fed an atherogenic diet, whereas the coronary atherosclerosis score was increased both in vasectomized males and in animals fed an atherogenic diet.