title: T(3) rapidly regulates several steps of alpha subunit glycoprotein (CGA) synthesis and secretion in the pituitary of male rats: Potential repercussions on TSH, FSH and LH secretion.
abstract: TSH, FSH and LH share the same glycoprotein alpha chain (CGA) as part of their protein structure. Therefore, it is possible that thyroid and gonadal dysfunction may affect the CGA expression. This study evaluated several steps of CGA synthesis and secretion in thyrotrophs and gonadotrophs of control and hypothyroid rats, acutely or chronically-treated with T3. Hypothyroidism increased the Cga mRNA expression and its association to ribosome, but decreased intracellular CGA content. These parameters were reversed after acute or chronic T3 treatment. We conclude that T3 not only down-regulates Cga mRNA expression, as expected, but also inhibits the association of Cga mRNA to ribosome, as well as the CGA secretion. These findings add novel insights into our understanding of the role of T3 on the regulation of the Cga gene expression and CGA secretion, which might have a potential repercussion in all pituitary glycoprotein hormone synthesis and secretion.
authors: Department of Physiology and Biophysics of the Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
authors: Paula
authors: P
authors: Bargi-Souza
authors: Department of Physiology and Biophysics of the Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
authors: Renata Marino
authors: RM
authors: Romano
authors: Department of Physiology and Biophysics of the Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
authors: Francemilson
authors: F
authors: Goulart-Silva
authors: Department of Physiology and Biophysics of the Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil.
authors: Erika Lia
authors: EL
authors: Brunetto
authors: Department of Physiology and Biophysics of the Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP, Brazil. Electronic address: mtnunes@icb.usp.br.
authors: Maria Tereza
authors: MT
authors: Nunes
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D015292:Glycoprotein Hormones, alpha Subunit / Q000235:genetics* / Q000378:metabolism*; D052681:Gonadotrophs / Q000378:metabolism; D007037:Hypothyroidism / Q000188:drug therapy* / Q000378:metabolism; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D010903:Pituitary Gland, Anterior / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012270:Ribosomes / Q000235:genetics; D052684:Thyrotrophs / Q000378:metabolism; D013972:Thyrotropin / Q000378:metabolism; D014284:Triiodothyronine / Q000008:administration & dosage* / Q000494:pharmacology
chemical_list: D015292:Glycoprotein Hormones, alpha Subunit; D014284:Triiodothyronine; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin
keywords: Alpha subunit; Gonadotrophs; Polysome profile; Thyrotrophs; Triiodothyronine