title: Manganese ion as a goitrogen in the female mouse.
abstract: Effect of excessive ingestion of manganese (Mn) on the mouse thyroid was assessed under the conditions of normal intake of iodide. Female mouse thyroids were enlarged after 7 weeks of administration of 200 mg/l MnCl2 X 4H2O in drinking water; 2.74 +/- 0.25 mg for control (N = 56), and 3.31 +/- 0.28 mg for Mn-treated group (N = 85) (p less than 0.001). In contrast, male mouse thyroids never became goitrous following this treatment. Manganese was goitrogenic to the castrated male mouse, but it had no effect on the testosterone-treated castrated male mouse, indicating the involvement of androgen in goiter formation. Oral administration of Mn did not severely affect blocked T/S of 125I or iodine metabolism in the thyroid. A morphological study, however, revealed that the epithelial cell in the Mn-treated mouse thyroid became flatter than that of the control. The lumens were filed with colloid in Mn-treated female mouse thyroid. The serum levels of thyroxine (T4), but not triiodothyronine (T3), were slightly reduced by Mn. These informations suggest that Mn can be a mild goitrogen for the female mouse and that the etiology of goiter formation can be interpreted by retention of colloid in the lumen.
mesh_terms: D000818:Animals; D002712:Chlorides; D005260:Female; D006042:Goiter / Q000139:chemically induced*; D008297:Male; D008345:Manganese / Q000378:metabolism; D017895:Manganese Compounds; D020149:Manganese Poisoning; D051379:Mice; D008815:Mice, Inbred Strains; D009929:Organ Size / Q000187:drug effects; D012737:Sex Factors; D013861:Thiocyanates / Q000494:pharmacology; D013961:Thyroid Gland / Q000033:anatomy & histology / Q000187:drug effects / Q000473:pathology; D014018:Tissue Distribution
chemical_list: D002712:Chlorides; D017895:Manganese Compounds; D013861:Thiocyanates; D008345:Manganese; C025340:manganese chloride