Ormandy G C, Jope R S
Department of Pharmacology, University of Alabama, Birmingham 35294.
Neurosci Lett. 1989 May 22;100(1-3):287-91. doi: 10.1016/0304-3940(89)90700-3.
The combination of carbachol and 20 mM K+ greatly stimulates phosphoinositide hydrolysis in rat cerebral cortical slices. This response was inhibited by sodium nitroprusside, an activator of guanylate cyclase which elevated guanosine 3',5'-monophosphate (cyclic GMP) levels. 8-Bromocyclic GMP and the phorbol ester phorbol myristate acetate (PMA) also inhibited phosphoinositide hydrolysis, and the inhibitory effect of PMA was additive with that of sodium nitroprusside. As guanylate cyclase is Ca2+-dependent this inhibition of phosphoinositide hydrolysis by cyclic GMP may serve as a feedback modulator of the production of inositol phosphates and the ensuing rise of intracellular calcium.
卡巴胆碱与20 mM钾离子联合使用可极大地刺激大鼠大脑皮质切片中的磷酸肌醇水解。这种反应受到硝普钠的抑制，硝普钠是一种鸟苷酸环化酶激活剂，可提高3',5'-环磷酸鸟苷（环鸟苷酸）水平。8-溴环鸟苷酸和佛波酯佛波醇肉豆蔻酸酯乙酸盐（PMA）也抑制磷酸肌醇水解，且PMA的抑制作用与硝普钠的抑制作用具有相加性。由于鸟苷酸环化酶依赖钙离子，环鸟苷酸对磷酸肌醇水解的这种抑制作用可能作为肌醇磷酸生成及随后细胞内钙升高的反馈调节剂。
