Impairment of Carbohydrate Metabolism of the Squirrel Monkey

Studies on over fifty squirrel monkeys have revealed the prevalence of an imbalance of carbohydrate metabolism. Nearly half of the colony of adult female monkeys were found to exhibit both abnormal glucose tolerance and diagnostic tolbutamide curves when maintained on a standard commercial diet and under satisfactory laboratory conditions. The impaired monkeys commonly demonstrated normal fasting blood sugar levels and were without overt symptoms of diabetes, although occasionally frank symptoms of hyperglycemia and glucosuria were found in the colony. Several impaired animals responded to treatment with oral tolbutamide with apparent restoration of normal carbohydrate metabolism, but tolbutamide treatment did not improve the glucose tolerance of others. Although prevalence of atherosclerosis exists also in adult squirrel monkeys, no correlation of serum cholesterol and nonesterified fatty acids was found between normal monkeys and animals with carbohydrate impairment.