Influence of Calcitonin on the Initial Uptake of Lead and Mercury by Bone

Summary Lead acetate (20 to 40 mg/kg body weight) or mercuric chloride (3 mg/kg body weight) was injected intravenously into normal rats and those pretreated with calcitonin (0.1 mU/g body wt/hr for 1-4 hr). Rats were sacrificed at intervals from 5 min to 24 hr after heavy metal injection. Tibias were prepared histologically, using Okada and Mimura's vital staining technique. The metaphyses and diaphyses were examined under the light microscope to study the effect of calcitonin on the uptake and distribution of these two metals in bone. Calcitonin dramatically reduced the initial uptake of lead and mercury by bone. This reduction, at least for lead, occurred in both trabecular and compact bone. The mechanism(s) by which calcitonin influences the distribution of lead and mercury in bone has not yet been determined.