Wood J G, Wicina G M, Cheung L Y
Department of Surgery, University of Kansas Medical Center, Kansas City 66103.
Am J Physiol. 1990 Mar;258(3 Pt 1):G440-6. doi: 10.1152/ajpgi.1990.258.3.G440.
The goal of this study was to compare the relative potency of histamine and its metabolite, 1,4-methylhistamine, as vasodilators of the gastric circulation. Changes in vascular resistance were measured during local intra-arterial infusion of graded doses of histamine and 1,4-methylhistamine to an ex vivo segment of dog stomach. Infusate concentrations were adjusted to deliver calculated arterial blood concentrations of 0, 3.7, 11, 33, 100, 300, and 900 ng/ml of each substance to the stomach segment. We found that histamine caused rapid dose-related decreases in gastric vascular resistance of up to -47.6 +/- 1.3% compared with control values. The effects of histamine were reversible when infusions ended. In contrast, there were no statistically significant changes in vascular resistance at any dose of 1,4-methylhistamine. In addition, modifications to previous methods using histamine antagonists resulted in greater attenuation of histamine-induced gastric vasodilation. Our results support a role for locally released histamine, but not for 1,4-methylhistamine, as a mediator of gastric vasodilation.
本研究的目的是比较组胺及其代谢产物1,4 - 甲基组胺作为胃循环血管舒张剂的相对效力。在向离体犬胃段局部动脉内输注不同剂量的组胺和1,4 - 甲基组胺期间，测量血管阻力的变化。调整输注液浓度，以使计算得出的每种物质的动脉血浓度为0、3.7、11、33、100、300和900 ng/ml输送至胃段。我们发现，与对照值相比，组胺引起胃血管阻力迅速出现剂量相关的下降，降幅高达-47.6±1.3%。输注结束时，组胺的作用是可逆的。相比之下，任何剂量的1,4 - 甲基组胺均未引起血管阻力出现统计学上的显著变化。此外，对使用组胺拮抗剂的先前方法进行改进后，组胺诱导的胃血管舒张作用得到了更大程度的减弱。我们的结果支持局部释放的组胺而非1,4 - 甲基组胺作为胃血管舒张介质的作用。
