Characterization of αT3-1 Cells Stably Transfected with Luteininzing Hormone β-Subunit Complementary Deoxyribonucleic Acid

Endocrine Journal

HARUHIKO KANASAKI¹  EISHICHI MIYAMOTO²  TOSHIE YONEHARA²  YOKO YAMADA²  HIDEYUKI YAMAMOTO²  KOHJI MIYAZAKI¹  KOHJI FUKUNAGA² 

[1] Department of Obstetrics and Gynecology, Shimane Medical University;Department of Pharmacology, Kumamoto University School of Medicine

关键词: Ca2+;    GnRH;    LH;    Pituitary hormones;    Signal transduction;   

DOI  :  10.1507/endocrj.50.341

学科分类：内分泌与代谢学

来源: Japan Endocrine Society

【 摘 要 】

References(38)Cited-By(2)Luteinizing hormone (LH) consists of α- and β-subunits, and synthesis and secretion of LH are regulated by gonadotropin-releasing hormone (GnRH). In order to examine the molecular mechanisms by which GnRH regulates LH secretion, we transfected αT3-1 cells with rat LHβ-subunit cDNA under the control of a constitutive promoter and established a stable cell line of LH2 cells which secreted LH in response to GnRH. Pulsatile and continuous GnRH pretreatments increased gene expression of the α-subunit and synthesis of LH, and enhanced the LH secretion by brief treatments with GnRH and 56 mM KCl. The LH secretions were partially blocked by elimination of extracellular Ca2+. GnRH-induced LH secretion was completely inhibited by calphostin C (a protein kinase C inhibitor) and 1 μM wortmannin. In contrast to the GnRH induction, high K+-induced LH secretion was inhibited by KN93, a Ca2+/calmodulin-dependent protein kinase II inhibitor, as well as by 1 μM wortmannin. We also confirmed that activation of cAMP-pathway induced LH secretion, but activation of mitogen-activated protein (MAP) kinase pathway was not involved in LH secretion. These results suggest that GnRH directly regulates LH secretion as well as LHβ-subunit synthesis, and that LH2 cells are a useful model for the study of LH secretion induced by several secretagogues.

【 授权许可】

Unknown