Mercer D W, Podolsky R S, Ritchie W P, Dempsey D T
Reichel Research Laboratory, Department of Surgery, Temple University Hospital, Philadelphia, Pennsylvania 19140.
Am Surg. 1993 Aug;59(8):479-83.
Topical isoproterenol protects the gastric mucosa from the severe necrosis induced by 100 per cent ethanol. Its effect on gastric mucosal blood flow is unknown. The purpose of this study was to determine the effect of topical isoproterenol on gastric mucosal blood flow and on the less severe gastric mucosal injury caused by dilute bile acid. Prior to injury with topical 5 mM acidified taurocholate (pH 1.2), stomachs were pretreated with either saline or isoproterenol (low dose = 50 micrograms/kg; high dose = 500 micrograms/kg). Mucosal injury was assessed by measuring net transmucosal ion fluxes (H, K) and the appearance of DNA into the gastric lumen (DNAE). Gastric mucosal blood flow was determined by using laser doppler. Pretreatment with isoproterenol significantly decreased bile acid-induced net transmucosal ion fluxes and luminal accumulation of DNA, suggesting mucosal protection. Furthermore, this effect was dose-dependent on H and DNAE but not K. Pretreatment with topical high dose isoproterenol had no significant effect on gastric mucosal blood flow. Thus, topical pretreatment with isoproterenol dose dependently protects the gastric mucosa from the superficial injury caused by the application of dilute bile acid. This protective effect appears to be mediated by a mechanism other than augmentation of gastric mucosal blood flow.
局部应用异丙肾上腺素可保护胃黏膜免受100%乙醇所致的严重坏死。其对胃黏膜血流的影响尚不清楚。本研究的目的是确定局部应用异丙肾上腺素对胃黏膜血流以及对由稀释胆汁酸引起的较轻胃黏膜损伤的影响。在用局部5 mM酸化牛磺胆酸盐（pH 1.2）损伤之前，胃分别用生理盐水或异丙肾上腺素（低剂量 = 50微克/千克；高剂量 = 500微克/千克）进行预处理。通过测量净跨黏膜离子通量（H、K）以及胃腔内DNA的出现情况（DNAE）来评估黏膜损伤。使用激光多普勒仪测定胃黏膜血流。异丙肾上腺素预处理显著降低了胆汁酸诱导的净跨黏膜离子通量和DNA在腔内的积聚，提示对黏膜有保护作用。此外，这种作用在H和DNAE方面呈剂量依赖性，但对K无此作用。局部高剂量异丙肾上腺素预处理对胃黏膜血流无显著影响。因此，局部应用异丙肾上腺素预处理可剂量依赖性地保护胃黏膜免受稀释胆汁酸所致的浅表损伤。这种保护作用似乎是由胃黏膜血流增加以外的机制介导的。
