Krivánek J
Neuroscience. 1983 Oct;10(2):545-52. doi: 10.1016/0306-4522(83)90151-3.
The effect of vanadate on the adenylate cyclase activity of rat cerebral cortex homogenates is described. In the absence of ethyleneglycol-bis-(beta-aminoethyl ether) N,N'-tetraacetic acid (EGTA), 10(-6)M vanadate inhibited enzyme activity by 23%, while 10 (-4) M and 10(-3) M stimulated the enzyme by 14 and 90%, respectively. In the presence of 0.2 mM EGTA, 10 (-6) M to 10(-3) M vanadate had only stimulating effects (18-450%). Additive effects of vanadate and noradrenaline on adenylate cyclase activity suggest different sites of action of these agents. Interaction of vanadate with both fluoride and guanyl-5'-yl imidodiphosphate had an apparently competitive character. Adenylate cyclase maximally stimulated by fluoride (10 mM) was inhibited by vanadate. This inhibitory effect was more pronounced in the absence of EGTA. Adenylate cyclase in the homogenates from the rat cerebral cortex in vivo invaded by spreading depression was slightly increased (up to 38%). This effect was abolished by low (10 (-7) M) vanadate. The results suggest that brain adenylate cyclase is stimulated by vanadate via the guanine nucleotide regulatory protein. The mechanism of vanadate's action, its modulation by calcium ions and the possible physiological role of these effects are discussed.
本文描述了钒酸盐对大鼠大脑皮质匀浆腺苷酸环化酶活性的影响。在不存在乙二醇双（β-氨基乙醚）N，N'-四乙酸（EGTA）的情况下，10（-6）M钒酸盐可使酶活性抑制23%，而10（-4）M和10（-3）M钒酸盐则分别使酶活性刺激14%和90%。在存在0.2 mM EGTA的情况下，10（-6）M至10（-3）M钒酸盐仅具有刺激作用（18 - 450%）。钒酸盐和去甲肾上腺素对腺苷酸环化酶活性的相加作用表明这些试剂的作用位点不同。钒酸盐与氟化物和鸟苷-5'-基亚氨基二磷酸的相互作用具有明显的竞争性。由氟化物（10 mM）最大程度刺激的腺苷酸环化酶被钒酸盐抑制。这种抑制作用在不存在EGTA时更为明显。在体内受扩散性抑制侵袭的大鼠大脑皮质匀浆中的腺苷酸环化酶略有增加（高达38%）。低浓度（10（-7）M）钒酸盐可消除这种作用。结果表明，大脑腺苷酸环化酶可通过鸟嘌呤核苷酸调节蛋白被钒酸盐刺激。本文讨论了钒酸盐的作用机制、其受钙离子的调节以及这些作用可能的生理作用。
