Insular amyloidosis and diabetes mellitus in Macaca nigra.

Amyloid in the islets of Langerhans increases with increasing severity of diabetes mellitus in Macaca nigra. The amount of insular amyloid was quantified, and diabetic monkeys averaged eight times more islet amyloid than did normal monkeys. The quantity of insular amyloid correlated significantly with glucose clearance in intravenous glucose tolerance tests and with serum glucose, triglycerides, immunoreactive insulin, and prebetallipoprotein measured after an overnight fast. As with human beings, insular amyloid appeared to be more prevalent in aging monkeys. The results support the hypothesis that the interrelated islet pathologic and metabolic events, which result in the appearance of insular amyloid concomitant with islet cell necrosis, may contribute more to maturity-onset diabetes in aging individuals than has been heretofore realized.