title: Neuropeptides in the thyroid gland: distribution of substance P and gastrin/cholecystokinin and their effects on the secretion of iodothyronine and calcitonin.
abstract: Previously, vasoactive intestinal polypeptide was localized to intrathyroidal nerve fibers. It stimulates iodothyronine secretion in mice. In the present study two populations of nerve fibers containing substance P and gastrin/cholecystokinin (CCK)-like immunoreactivity, respectively, were demonstrated in the thyroid gland of several mammals. The substance P fibers occurred around blood vessels and follicles, whereas the gastrin/CCK fibers occurred mainly around follicles. In the chicken thyroid and ultimobranchial glands only substance P-containing fibers could be demonstrated. Such fibers were particularly numerous in the ultimobranchial gland. CCK-4, CCK-8, and substance P did not increase thyronine secretion measured as release of radioiodine into the circulation of mice pretreated with Na125I and T4. The TSH-induced release of radioiodine was also unaffected. Calcitonin secretion in rats was stimulated by CCK-4, CCK-8, substance P, and vasoactive intestinal polypeptide.
mesh_terms: D000818:Animals; D002116:Calcitonin / Q000378:metabolism*; D002415:Cats; D002417:Cattle; D002645:Chickens; D002766:Cholecystokinin / Q000032:analysis* / Q000494:pharmacology; D005755:Gastrins / Q000032:analysis* / Q000494:pharmacology; D006168:Guinea Pigs; D051379:Mice; D051381:Rats; D012756:Sheep; D013373:Substance P / Q000032:analysis* / Q000494:pharmacology; D013552:Swine; D013961:Thyroid Gland / Q000032:analysis* / Q000378:metabolism; D013970:Thyronines / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D005755:Gastrins; D013970:Thyronines; C013068:3-monoiodothyronine; D013373:Substance P; D002116:Calcitonin; D002766:Cholecystokinin