Stimulatory effect of calcitonin on calcium uptake and glucose production in isolated rat hepatocytes.

The biological effect of calcitonin (CT) was investigated in isolated rat hepatocytes. Addition of synthetic [Asu1,7] eel CT (20 and 40 ng/ml of medium with 2.5 mg dry weight of cells) into the medium containing calcium ion produced a marked elevation of calcium uptake in the hepatocytes, when calcium concentrations in the medium were monitored spectrophotometrically using arsenazo III. Intracellular calcium contents in the mitochondria and microsomes were significantly increased by CT addition. Meanwhile, glycogenolysis and gluconeogenesis in the hepatocytes were significantly stimulated by addition of CT (10, 10(2), and 10(3) ng/ml of medium with 5 mg dry weight of cells) into the medium containing calcium, although CT effects were less than those effects of 10(-7) M glucagon and 10(-5) M phenylephrine. These data clearly indicate that CT stimulates calcium uptake and glucose production in the hepatocytes, suggesting that CT has an effect in the metabolic function of rat liver cells.