Young adult male mice were injected intraperitoneally twice daily with the globulin fraction of anti-insulin sera. Control mice received injections of the same fraction from guinea pigs immunized with Freund's adjuvant only. Blood glucose levels in the mice injected with insulin antibodies were continuously maintained over 250 mg. per 100 ml.
Mice were killed before and at 1, 3, 6, 10 and 15 days after the injections started. Thymidine-H-3 was injected subcutaneously two hours before killing. The following observations were made:
(1) Beta cells quickly lost their granules and remained degranulated throughout the period of injections of insulin antibodies. Swelling of the Golgi complex and other histological evidence of increased cellular activity were present. Neutrophils, eosinophils and monocytes accumulated around the islets in the mice injected with antibody.
(2) In the control mice the number of labeled beta cell nuclei (radioactive index) ranged from seven to twenty-five per 3,000 nuclei of beta cells. Labeled beta cells were scattered throughout the islets. Alpha cells showed a lower radioactive index, one to three per 1,000 nuclei.
In the mice injected with antibody the radioactive index was within the normal range on the first day, reached a peak in mice killed on the third day and subsequently progressively declined in spite of the sustained hyperglycemia.
