Calcitonin stimulates glycogenolysis in the liver of fasted rats

The effect of calcitonin (CT) on glycogenolysis in the liver was investigated in fasted rats. The fasting produced a marked decrease in the hepatic glycogen content. Thyroparathyroidectomy (TPTX) significantly prevented the decline in hepatic glycogen by fasting as compared with sham operation. This prevention by TPTX was clearly relieved by the subcutaneous administration of CT (80 MRC mU/100 g body weight). The appreciable effect of the hormone was also observed at the dose of 20 and 40 MRC mU CT/100 g body weight. The present results suggest that CT plays a physiological role in the stimulation of hepatic glycogenolysis after fasting in rats.