title: Thyroidectomy induces neurofilament expression in adenohypophyses of rats.
abstract: We studied the effect of thyroidectomy on neurofilament expression in adenohypophyses of rats. The question of whether thyroxine (T4) administration can reduce this effect was also investigated. Rats were divided into: 1. Euthyroid controls, 2. Thyroidectomized 20 d (Tx 20 d), 3. Thyroidectomized 20 d with replacement of T4 (Tx 20 d + T4 20 d), 4. Thyroidectomized 40 d (Tx 40 d), 5. Thyroidectomized 40 d with replacement of T4 20 d after surgery (Tx 40 d + T4 20 d). Adenohypophyses were studied by immunohistochemistry and Western blot analysis using antibodies against neurofilament 200 kDa (NF-H) and thyroid-stimulating hormone (TSH). The number of thyrotrophs with immunoreactivity for NF-H was increased in Tx 20 d and Tx 40 d rats, whereas T4 administration protected the effect of thyroidectomy. In the thyroidectomized animals, thyrotrophs showed eccentric nuclei and the cytoplasm was full of NF-H immunoreactivity, whereas in T4 treated rats, the thyrotrophs were similar to control. Western blot analysis showed that NF-H expression increased in rats thyroidectomized for 20 and 40 d. T4 given immediately or 20 d after thyroidectomy caused no changes in NF-H expression. We conclude that thyroidectomy induces NF-H expression in adenohypophyses of rats and administration of T4 decreases this effect.
authors.affiliation: Department of Physiology and Pharmacology, Centro de Ciencias Básicas, Universidad Autónoma de Aguascalientes, México.
authors.forename: E
authors.initials: E
authors.lastname: Salinas
authors.forename: J L
authors.initials: JL
authors.lastname: Quintanar
mesh_terms: D000818:Animals; D015153:Blotting, Western; D005260:Female; D007150:Immunohistochemistry; D016900:Neurofilament Proteins / Q000096:biosynthesis*; D009929:Organ Size / Q000187:drug effects; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013965:Thyroidectomy; D013972:Thyrotropin / Q000097:blood; D013974:Thyroxine / Q000097:blood / Q000494:pharmacology
chemical_list: D016900:Neurofilament Proteins; D013972:Thyrotropin; D013974:Thyroxine