title: Post-vagotomy changes in the ultrastructure of the thyroid gland and circulating levels of its hormones in the pigeon.
abstract: Pigeons subjected to bilateral cervical vagotomy, were investigated for changes in the ultrastructure of the thyroid and circulating levels of the thyroid hormones, T4 and T3. Vagotomy caused pronounced activation of the thyroid follicular cells which was characterized by considerable enlargement of the cells, increase in colloid droplets, mitochondria, lysosomes and microvilli, and a well developed Golgi complex. As for the blood levels of T4 and T3, there was significant decrease in T4, but an increase in T3. These changes have been attributed to the absence of the inhibitory influence of the parasympathetic tone caused by vagotomy.
mesh_terms: D000818:Animals; D010856:Columbidae / Q000033:anatomy & histology* / Q000502:physiology; D006056:Golgi Apparatus / Q000648:ultrastructure; D008247:Lysosomes / Q000648:ultrastructure; D008854:Microscopy, Electron; D008928:Mitochondria / Q000648:ultrastructure; D013961:Thyroid Gland / Q000294:innervation* / Q000378:metabolism / Q000648:ultrastructure; D013974:Thyroxine / Q000097:blood*; D014284:Triiodothyronine / Q000097:blood*; D014628:Vagotomy; D014630:Vagus Nerve / Q000502:physiology*
chemical_list: D014284:Triiodothyronine; D013974:Thyroxine