title: Degranulation and appearance of vesicular inclusions in canine C cells after administration of antithyroid drug.
abstract: When stimulated by the feeding of ethylenethiourea for a period of 6 months, dog thyroid glands increased to approximately 30 times their normal size. Not only follicular cells but also C cells had hyperplastic and hypertrophic features, compared with normal controls there was in the C cells a marked decrease in secretory granules immunoreactive for calcitonin. Furthermore, vesicular inclusions of various sizes and dilated nuclear enveloped, which showed a positive immunoreaction for calcitonin, were observed in the C cells. These findings indicate that the antithyroid drug interferes with synthesis of calcitonin by C cells probably by inhibiting the conversion of a larger precursor to calcitonin by C cells, probably by inhibiting the conversion of a larger precursor to calcitonin.
mesh_terms: D000818:Animals; D002116:Calcitonin / Q000032:analysis; D002467:Cell Nucleus / Q000648:ultrastructure; D003594:Cytoplasmic Granules / Q000032:analysis / Q000187:drug effects*; D004285:Dogs; D005031:Ethylenethiourea / Q000494:pharmacology*; D007093:Imidazoles / Q000494:pharmacology*; D002479:Inclusion Bodies / Q000032:analysis / Q000187:drug effects*; D013961:Thyroid Gland / Q000187:drug effects* / Q000648:ultrastructure
chemical_list: D007093:Imidazoles; D005031:Ethylenethiourea; D002116:Calcitonin