Chung S C, Leung J W, Leung F W
Department of Surgery, Chinese University of Hong Kong, Prince of Wales Hospital.
Dig Dis Sci. 1990 Aug;35(8):1008-11. doi: 10.1007/BF01537250.
Clinical studies have demonstrated the efficacy of submucosal epinephrine injection in the control of bleeding ulcers. Since endoscopic techniques for assessing gastroduodenal blood flow are limited, we employed an animal model to study the mechanism of control of bleeding. The effect of submucosal epinephrine injection on local gastric blood flow was studied in the rat using laser Doppler flowmetry and reflectance spectrophotometry. Submucosal injection of 0.1 ml of 1/10,000 epinephrine caused a significantly greater drop in local gastric blood flow (laser Doppler flowmetry) compared with vehicle (10% sodium metabisulfite) injection. The reduction persisted for up to 120 min. This vasoconstrictive effect of epinephrine was confirmed by observations with reflectance spectrophotometry, which documented a pattern of ischemia without congestion (lower index of hemoglobin concentration, lower index of oxygen saturation). The autoregulatory escape from adrenergic vasoconstriction was not evident in either instance. We conclude that, after submucosal injection of epinephrine, the absence of autoregulatory escape from adrenergic vasoconstriction and the marked and prolonged decrease in local gastric blood flow enhance the homeostatic mechanisms (eg, platelets and other coagulative factors) to effect hemostasis in bleeding ulcers.
临床研究已证实黏膜下注射肾上腺素在控制溃疡出血方面的疗效。由于评估胃十二指肠血流的内镜技术有限，我们采用动物模型来研究出血控制机制。使用激光多普勒血流仪和反射分光光度法在大鼠中研究黏膜下注射肾上腺素对局部胃血流的影响。与注射赋形剂（10%焦亚硫酸钠）相比，黏膜下注射0.1 ml 1/10,000肾上腺素导致局部胃血流（激光多普勒血流仪）显著下降。这种降低持续长达120分钟。肾上腺素的这种血管收缩作用通过反射分光光度法的观察得到证实，该方法记录了缺血而非充血的模式（血红蛋白浓度指数降低，氧饱和度指数降低）。在这两种情况下，均未明显观察到对肾上腺素能血管收缩的自动调节逃逸。我们得出结论，黏膜下注射肾上腺素后，缺乏对肾上腺素能血管收缩的自动调节逃逸以及局部胃血流显著且持续的减少增强了止血机制（如血小板和其他凝血因子），从而实现对出血性溃疡的止血。
