Sandvik A K, Brenna E, Waldum H L
Department of Medicine, University Hospital, Trondheim, Norway.
Am J Physiol. 1993 Jan;264(1 Pt 1):G51-6. doi: 10.1152/ajpgi.1993.264.1.G51.
This study examined the second messenger system responsible for gastrin-induced histamine release from the rat stomach. We examined the effect of different concentrations of ionized calcium, the calcium-channel blockers verapamil and nicardipine, and the intracellular calcium-chelator 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid/acetoxymethyl ester (BAPTA/AM) on gastrin-stimulated histamine release in the totally isolated vascularly perfused rat stomach. Moreover, the effect on baseline histamine release of caffeine as well as of forskolin and 3-isobutyl-1-methylxanthine (IBMX) was tested. Gastrin induced an immediate 10- to 15-fold increase in venous histamine. Perfusate ionized calcium in the 0.25-1.25 mM range did not affect histamine release; histamine release was attenuated by the 0.00 and 1.75 mM calcium concentrations. Verapamil, nicardipine, and BAPTA/AM inhibited gastrin-stimulated histamine release. Caffeine stimulated the release, whereas forskolin and IBMX had no effect. We conclude that gastrin-induced histamine release from the rat stomach is mediated by calcium, probably both from the intracellular pool and by transmembrane flux from the extracellular space.
本研究检测了负责胃泌素诱导大鼠胃组胺释放的第二信使系统。我们检测了不同浓度的游离钙、钙通道阻滞剂维拉帕米和尼卡地平以及细胞内钙螯合剂1,2-双(2-氨基苯氧基)乙烷-N,N,N',N'-四乙酸/乙酰氧基甲酯（BAPTA/AM）对完全离体的血管灌注大鼠胃中胃泌素刺激的组胺释放的影响。此外，还测试了咖啡因以及福斯高林和3-异丁基-1-甲基黄嘌呤（IBMX）对基础组胺释放的影响。胃泌素使静脉组胺立即增加10至15倍。灌注液中0.25 - 1.25 mM范围内的游离钙不影响组胺释放；0.00和1.75 mM的钙浓度使组胺释放减弱。维拉帕米、尼卡地平和BAPTA/AM抑制胃泌素刺激的组胺释放。咖啡因刺激组胺释放，而福斯高林和IBMX则无作用。我们得出结论，胃泌素诱导的大鼠胃组胺释放由钙介导，可能来自细胞内钙库以及细胞外空间的跨膜钙流。
