Functional expression of rat pituitary gonadotrophin-releasing hormone receptors in Xenopus oocytes.
Expression of receptors for the hypothalamic regulatory peptide, gonadotrophin-releasing hormone (GnRH), was investigated by intracellular recording from Xenopus oocytes injected with poly(A)+ mRNA isolated from rat anterior pituitary glands. Membrane depolarizations were induced in oocytes in a dose-dependent fashion following the application of GnRH (10nM - 1 microM) or a GnRH superactive agonist, buserelin (1nM - 1 microM). The response was reversibly blocked by the addition of a GnRH antagonist (1 microM). TRH (10nM - 1 microM) had no effect on most of these oocytes. In contrast, some other oocytes which showed no responses to GnRH or to the GnRH agonist, displayed depolarizing responses to TRH (10nM - 1 microM). A relatively small number of oocytes responded to both ligands. Control oocytes did not respond to the GnRH analogues or to TRH. This successful expression of the GnRH receptor could provide a new approach to the study of the receptor, and serve as a means for the isolation and cloning of the encoding genes.
Eidne
K A
KA
MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, United Kingdom.
McNiven
A I
AI
Taylor
P L
PL
Plant
S
S
House
C R
CR
Lincoln
D W
DW
Yoshida
S
S
D000818:Animals; D005260:Female; D005786:Gene Expression Regulation; D066298:In Vitro Techniques; D008564:Membrane Potentials; D008845:Microinjections; D009865:Oocytes / Q000378:metabolism; D010903:Pituitary Gland, Anterior / Q000032:analysis; D011061:Poly A / Q000302:isolation & purification; D012333:RNA, Messenger / Q000302:isolation & purification; D051381:Rats; D011919:Rats, Inbred Strains; D011966:Receptors, LHRH / Q000096:biosynthesis* / Q000235:genetics; D017981:Receptors, Neurotransmitter / Q000235:genetics / Q000378:metabolism; D018025:Receptors, Thyrotropin-Releasing Hormone; D014982:Xenopus laevis
D012333:RNA, Messenger; D011966:Receptors, LHRH; D017981:Receptors, Neurotransmitter; D018025:Receptors, Thyrotropin-Releasing Hormone; D011061:Poly A