Dopamine inhibits TRH-induced MAP kinase activation in dispersed rat anterior pituitary cells.
We recently reported the existence of two separate pathways for thyrotropin-releasing hormone (TRH)-induced mitogen-activated protein (MAP) kinase activation in GH3 pituitary tumor cells. To test the role of MAP kinase in TRH action, we examined the effect of dopamine (DA) on TRH-induced MAP kinase in primary cultures of rat anterior pituitary cells. 1 microM of DA attenuated 1 microM TRH-induced MAP kinase activity and phosphorylation. 100 ng/ml of islet-activating protein (IAP) blocked these inhibitory effects of DA. These results suggest that crosstalk exists between the DA signaling pathway and the TRH-stimulated MAP kinase activating pathway in rat anterior pituitary cells.
Ohmichi
M
M
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
Koike
K
K
Nohara
A
A
Kanda
Y
Y
Sakamoto
T
T
Zhang
Z X
ZX
Hirota
K
K
Miyake
A
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D002478:Cells, Cultured; D004298:Dopamine / Q000494:pharmacology* / Q000502:physiology; D004789:Enzyme Activation; D037342:Pertussis Toxin; D010766:Phosphorylation; D010903:Pituitary Gland, Anterior / Q000201:enzymology*; D051381:Rats; D015398:Signal Transduction; D013973:Thyrotropin-Releasing Hormone / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D010566:Virulence Factors, Bordetella; D013973:Thyrotropin-Releasing Hormone; D000255:Adenosine Triphosphate; D037342:Pertussis Toxin; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D004298:Dopamine