Serum Concentrations of Ionized Calcium and Calcitonin under Basal and Hypercalcemic States in Oophorectomized Rats
It is very important to measure serum ionized calcium (iCa) accurately in the evaluation of calcitonin (CT) secretion in patients with abnormal Ca metabolism. To evaluate CT secretion in relation to iCa concentration, a newly developed calcium ion analyzer which simultaneously measured the pH level was used. In oophorectomized rats (deficiency of E2), regardless of normal iCa level, a low basal CT concentration was found. However, normal capacity of CT secretion in response to hypercalcemic stimulation was observed. Therefore, this low basal CT level might be dependent not on the iCa level but on other factor.