Summary: In order to evaluate the value of diabetic Japanese monkeys (Macaca fuscatus) as an animal model studying the pathogenesis of diabetic neuropathy, morphological examinations were performed on myelinated nerve fibers and endoneurial microvessels at three levels of the lower limb nerve in six streptozotocin (STZ)-diabetic monkeys with the duration of diabetes up to 36 months and in six roughly age-matched control monkeys using a computer-assisted image analyzer. Nerve fiber loss was not found, although a tendency for nerve fiber atrophy was found in diabetic monkeys. Endoneurial microvessels did not show either endothelial or pericyte proliferation or basement membrane thickening. The results suggest that chronically STZ-diabetic Japanese monkeys with the duration of diabetes up to 36 months might be useful for studying diabetic axonopathy, but do not closely mimic the nerve pathology found in human diabetic neuropathy.
Animals: Fourteen Japanese monkeys (Macaca fuscatus) weighing 3.7～8.7 kg were used as experimental animals. None of the monkeys showed glycosuria or proteinuria by paper strip test before the experiment. Eight monkeys were made diabetic by a single injected of 50 mg/kg STZ dissolved in citrate buffer into the femoral vein. All monkeys that received STZ showed glycosuria within at least 2 days after the injection and persistent glycosuria was noted before death. The plasma glucose level was determined one or more times in eight diabetic monkeys. They were kept in cages and fed on monkey chow (Oriental Yeast Co., Ltd., Japan) supplemented by fruit and sweet potatoes and free access to water along with the remaining six monkeys which were used as controls.
