Jakobs K H, Minuth M, Aktories K
J Recept Res. 1984;4(1-6):443-58. doi: 10.3109/10799898409042566.
The influence of sodium was studied on hormone and guanine nucleotide-induced stimulation and inhibition of adenylate cyclase and on beta-adrenoceptor binding in various membrane systems. Sodium exerted almost identical effects on stimulation and inhibition of adenylate cyclase by various stimulatory and inhibitory hormones in all of the systems studied. The potencies of the hormones and of GTP to increase or to decrease the enzyme activity were reduced by sodium ions, without changing the maximal degree of adenylate cyclase stimulation or inhibition. Stimulation and inhibition of adenylate cyclase by the stable GTP analog, GTP gamma S, was affected in an identical manner by sodium, causing a retardation in the onset without a change in final stimulation or inhibition by the analog. Similar to the well-known reduction in alpha 2-adrenoceptor affinity for agonists, sodium also reduced the apparent affinity of beta-adrenoceptors for the agonist, isoproterenol. It is concluded that sodium exerts identical effects on Ns and Ni, inhibiting the activation process of these two coupling components of the adenylate cyclase.
研究了钠对激素和鸟嘌呤核苷酸诱导的腺苷酸环化酶刺激与抑制作用以及对各种膜系统中β-肾上腺素能受体结合的影响。在所研究的所有系统中，钠对各种刺激和抑制激素诱导的腺苷酸环化酶刺激与抑制作用几乎具有相同的影响。激素和GTP增强或降低酶活性的效力因钠离子而降低，但腺苷酸环化酶刺激或抑制的最大程度未发生改变。稳定的GTP类似物GTPγS对腺苷酸环化酶的刺激与抑制作用受钠的影响方式相同，导致起效延迟，但类似物最终的刺激或抑制作用未改变。与众所周知的α2-肾上腺素能受体对激动剂的亲和力降低类似，钠也降低了β-肾上腺素能受体对激动剂异丙肾上腺素的表观亲和力。得出的结论是，钠对Ns和Ni具有相同的作用，抑制腺苷酸环化酶这两个偶联成分的激活过程。
