No effect of verapamil on calcium stimulated calcitonin release

We investigated the effect of infusing 5 mg/h of verapamil on calcitonin release in normal males. After 60 minutes of infusion, ionized calcium and calcitonin levels were unchanged. At 60 minutes we infused 3 mg/kg of body weight of elemental calcium over 10 minutes and we found that calcitonin release was no different from when the subjects were receiving verapamil. These results suggest that, despite blocking calcium channels, acute hypercalcaemia produces normal calcitonin release.