van der Vliet A, Bast A, Timmerman H
Vrije Universiteit, Faculty of Chemistry, Department of Pharmacochemistry, Amsterdam, The Netherlands.
Agents Actions. 1990 Apr;30(1-2):206-9. doi: 10.1007/BF01969039.
Rat cortical slices preloaded with [3H]histidine released [3H]histamine upon electrical stimulation or after depolarization with elevated K+ levels. The release was dependent on the presence of Ca2+, suggesting a neurosecretory process. Histamine has been shown to inhibit its own release mediated by an autoreceptor belonging to the H3-receptor subclass. In this study we have investigated the autoinhibition using different electrical field stimulation conditions (1, 10, 20 and 33.3 Hz). Applying electrical stimulation, the inhibition of [3H]histamine release by histamine is decreased when the stimulation frequency is elevated. When stimulated with 1 Hz histamine is able to block [3H]histamine release completely, with a p(EC50) of 8.1 +/- 0.1. At higher frequencies histamine still blocks [3H]histamine release completely, but with a lower p(EC50).
预先加载[3H]组氨酸的大鼠皮层切片在电刺激或用升高的钾离子水平去极化后释放[3H]组胺。这种释放依赖于钙离子的存在，提示这是一个神经分泌过程。组胺已被证明可抑制其自身由属于H3受体亚类的自身受体介导的释放。在本研究中，我们使用不同的电场刺激条件（1、10、20和33.3Hz）研究了这种自身抑制作用。施加电刺激时，当刺激频率升高时，组胺对[3H]组胺释放的抑制作用减弱。当以1Hz刺激时，组胺能够完全阻断[3H]组胺的释放，p(EC50)为8.1±0.1。在更高频率下，组胺仍能完全阻断[3H]组胺的释放，但p(EC50)较低。
