The effect of thyroxine treatment on the dynamics of insulin release from the isolated perfused rat pancreas

Summary The isolated perfused pancreas obtained from rats treated with thyroxine (600 g/kg/day, for five days) showed a modified insulin secretory pattern. Glucose (300 mg/100 ml) induced a higher first peak of insulin secretion which appeared slightly faster than in controls. The delayed second peak, as induced by glucose in the normal rat pancreas was absent after thyroxine treatment. Tolbutamide (20 mg/100 ml) yielded a slightly higher first peak followed by a moderately increased basal insulin secretion in the treated group.