Influence of Atmospheric Temperature upon Reaction of Rabbits to Insulin.

Abstract

The higher mortality among white rats and white mice when kept at atmospheric temperatures considerably higher than normal, after receiving injections of insulin, and their increased inclination to convulse has frequently been reported. Others have found, however, that the inclination of white mice to convulse is the same at 30°C as at 18°-20°C. It has also been found that rabbits acclimated at a temperature of 30°C required but one-half as much insulin to produce the same percentage of blood sugar reduction as those at 22°C. It was observed in the present experiments that rabbits which responded with mild convulsions, when injected with a prescribed amount of insulin at normal room temperatures, collapsed completely with the first onset of convulsions and expired forthwith after being injected with the same amount of insulin during extremely hot weather (31° to 34°), if not given immediate intravenous injections of glucose. The rabbits used were divided into 3 groups, A, B, and C. Those of group C were inclined to convulse after injections of 0.375 units of insulin per kg of body weight, those of group B with 0.5 units, while those of group A did not convulse with the larger amount. They were used but once a week and were fasted for 18 hours before each experiment. The dosage of insulin in each of these experiments was 0.375 units of crystalline zinc insulin per kg of body weight. Samples of blood were taken from each animal just before it was injected with insulin and similar samples taken each hour thereafter for 7 hours to determine the nature of the subsequent changes in the blood sugar level.