Effect of calcitonin in calcium transport in isolated rat mitochondria

Abstract

The effect of synthetic salmon calcitonin (SCT) on Ca2+ transport by isolated liver mitochondria has been studied.In the presence of inorganic phosphate SCT accelerates the calcium induced oxygen rate consumption, shortens the stimulated respiration time and diminishes the amounts of O2 consumed.Determination of the Ca2+ accumulated during respiration shows that the uptake rate of Ca2+ increases rapidly with SCT concentration reaching a steady value.There are no appreciable changes on the rate of H+ ejection due to calcitonin with mitochondria incubated with NEM.However pulses of SCT on previously polarized mitochondria produce instantaneous acceleration on H+ ejection.These results agree with a possible participation of mitochondria on the hypocalcemia induced by calcitonin.