Takeuchi K, Nobuhara Y, Okabe S
Dig Dis Sci. 1985 Nov;30(11):1072-8. doi: 10.1007/BF01315605.
Influence of luminal Ca2+ on the integrity of normal mucosa and recovery of damaged mucosa in anesthetized rat stomachs was studied using a perfusion system. Changes in the mucosal integrity were monitored by measuring transmucosal potential difference (PD) and luminal pH. EDTA, a Ca2+ chelator, dose-dependently reduced PD and increased luminal pH. Five mM Ca2+ (CaCl2) alone produced no changes in either PD and luminal pH, but the PD which was reduced by 250 mM EDTA was significantly recovered. Ethanol or NaCl concentration-dependently reduced PD, but gradually reverted to baseline levels. While 5 mM Ca2+ or 5 mM EDTA did not influence the reduction in PD with 50% ethanol and 1 M NaCl, these agents either enhanced or delayed the recovery processes in reduced PD, respectively. Five mM Ca2+ enhanced the recovery of PD which was reduced by 50% ethanol plus 5 mM EDTA. Gastric damage induced by 50% ethanol plus 5 mM EDTA was much more severe than that induced by 50% ethanol alone or 50% ethanol plus 5 mM Ca2+. Both 50% ethanol and 1 M NaCl significantly increased Ca2+ contents in the gastric lumen. Luminal Ca2+ appears to play an important role in maintaining mucosal integrity, under normal physiological conditions, and in accelerating the recovery process of damaged mucosa in rat stomachs.
使用灌注系统研究了管腔内Ca2+对麻醉大鼠胃正常黏膜完整性和受损黏膜恢复的影响。通过测量跨黏膜电位差（PD）和管腔内pH值来监测黏膜完整性的变化。Ca2+螯合剂乙二胺四乙酸（EDTA）剂量依赖性地降低了PD并升高了管腔内pH值。单独使用5 mM Ca2+（CaCl2）对PD和管腔内pH值均无影响，但250 mM EDTA降低的PD得到了显著恢复。乙醇或氯化钠浓度依赖性地降低了PD，但随后逐渐恢复到基线水平。虽然5 mM Ca2+或5 mM EDTA对50%乙醇和1 M氯化钠引起的PD降低没有影响，但这些试剂分别增强或延迟了降低的PD的恢复过程。5 mM Ca2+增强了由50%乙醇加5 mM EDTA降低的PD的恢复。50%乙醇加5 mM EDTA诱导的胃损伤比单独50%乙醇或50%乙醇加5 mM Ca2+诱导的损伤严重得多。50%乙醇和1 M氯化钠均显著增加了胃腔内的Ca2+含量。在正常生理条件下，管腔内Ca2+似乎在维持黏膜完整性以及加速大鼠胃受损黏膜恢复过程中发挥重要作用。
