No effect of cimetidine on calcitonin secretion from medullary thyroid carcinoma.
The effect of cimetidine on basal and pentagastrin-stimulated serum immunoreactive calcitonin (S-iCT) concentrations was studied in six patients with medullary carcinoma of the thyroid (MCT). Basal S-iCT was elevated in all patients and showed a marked increase after i.v. injection of pentagastrin, 0.5 micrograms/kg b.wt. Cimetidine, 200 mg i.v., 30 min before administration of pentagastrin had no effect on either basal or pentagastrin-stimulated S-iCT. Thus, the mechanisms of basal and pentagastrin-stimulated calcitonin secretion from MCT do not seem to involve agonism with histamine H2-receptors.
D000328:Adult; D000368:Aged; D002116:Calcitonin / Q000097:blood / Q000378:metabolism*; D002277:Carcinoma / Q000378:metabolism*; D002927:Cimetidine / Q000494:pharmacology*; D005260:Female; D006146:Guanidines / Q000494:pharmacology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010418:Pentagastrin / Q000494:pharmacology; D011863:Radioimmunoassay; D013964:Thyroid Neoplasms / Q000378:metabolism*; D013997:Time Factors
D006146:Guanidines; D002927:Cimetidine; D002116:Calcitonin; D010418:Pentagastrin