Conditioning of insulin-induced glycemia

Results of 3 experiments indicate that, following a training series of insulin injections in rats, injection of a physiological saline placebo led to an elevation in blood glucose level. Exp. I with 70 naive male Sprague-Dawley rats, demonstrated that the time course of this apparent conditioned hyperglycemia approximately mirrored the time course of the insulin-induced hypoglycemia. Exp. II with 48 albino rats, indicated that the magnitude of the placebo-elicited hyperglycemia was related to the insulin dose used during training. Since the results of these 2 experiments contradicted previous reports of a conditioned, insulin-like hypoglycemia following training with the hormone. Exp. III, with 16 naive male albino Wistar rats, was designed as a direct replication of the previous research. In contrast with the previously reported results, but in agreement with the results of Exp. I and II, a hyperglycemia CR was again evidenced in Exp. III. (24 ref.)