Yamada M, Yamada M, Watson M A, Richelson E
Department of Psychiatry and Psychology, Mayo Foundation, Jacksonville, FL 32224.
Eur J Pharmacol. 1993 Jan 4;244(1):99-101. doi: 10.1016/0922-4106(93)90064-g.
Recently, we reported that the rat neurotensin receptor expressed in transfected Chinese hamster ovary cells (CHO-rNTR-10) mediates the hydrolysis of polyphosphoinositides. In this study, we show that neurotensin stimulated cyclic AMP formation in CHO-rNTR-10 cells in a dose-dependent manner (EC50 = 34 nM). Neurotensin also stimulated cyclic AMP formation in membranal preparations under Ca(2+)-free conditions. These results suggest that this cyclic AMP formation occurs from direct coupling of the neurotensin receptor to a type of GTP binding protein, mediating synthesis of cyclic AMP, and not from an increase in intracellular Ca2+ concentration from polyphosphoinositide hydrolysis.
最近，我们报道了转染的中国仓鼠卵巢细胞（CHO-rNTR-10）中表达的大鼠神经降压素受体介导多磷酸肌醇的水解。在本研究中，我们发现神经降压素以剂量依赖方式刺激CHO-rNTR-10细胞中环状AMP的生成（半数有效浓度=34 nM）。在无钙条件下，神经降压素也刺激膜制剂中环状AMP的生成。这些结果表明，这种环状AMP的生成是由于神经降压素受体与一种介导环状AMP合成的GTP结合蛋白直接偶联所致，而非多磷酸肌醇水解导致细胞内钙离子浓度升高所致。
