Immortalized anterior pituitary alpha T3 gonadotropes contain functional luteinizing hormone/human chorionic gonadotropin receptors.
Immortalized alpha T3 gonadotropes contain a major 5.0-kb and minor 3.6-, 2.4- and 1.6-kb luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor transcripts and an 80-kDa receptor protein which can specifically bind 125I-hCG. The relative abundance of the receptors in alpha T3 cells is, however, lower than in gonadal tissues. Culturing alpha T3 cells with highly purified hCG resulted in a dose- and time-dependent and hormone-specific increase in steady-state levels of LH-alpha subunit mRNA. Culturing alpha T3 cells with hCG also resulted in a concomitant increase in the LH-alpha protein levels. As expected, culturing with GnRH also resulted in an increase of LH-alpha subunit mRNA and protein levels. In summary, we conclude that alpha T3 cells contain LH/hCG receptors which are functionally coupled to the up-regulation of LH-alpha subunit gene expression.
Huang
Z H
ZH
Department of Obstetrics and Gynecology, University of Louisville School of Medicine, KY 40292, USA.
Lei
Z M
ZM
Rao
C V
CV
D000818:Animals; D002460:Cell Line; D006063:Chorionic Gonadotropin / Q000378:metabolism / Q000494:pharmacology; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D007150:Immunohistochemistry; D008970:Molecular Weight; D010053:Ovary / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011974:Receptors, LH / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D006063:Chorionic Gonadotropin; D012333:RNA, Messenger; D011974:Receptors, LH