Effects of gastric mucosal blood flow (GMBF) on the role of adaptive cytoprotection of rat gastric mucosa

By the use of hydrogen gas clearance technique, we have investigated the role ofGMBF in the adaptive cytoprotection induced by intragastric per fusion with low concentration prior to high concentration of HCl plus ethanol. The results were as follows:(1) intragastric perfusion with low concentration prior to high concentration of HClplus ethanol led to an adaptive cytoprotection, i. e., the gross and the deep damage weredecreased by 47. 09 % and 44. 57% respectively, as compared with those caused byhigh concentration of HCl plus ethanol alone; correspondingly, GMBF also showed anadaptive hyperemic response, i. e., GMBF was increased by 28. 02% as comparedwith that due to high concentration alone; (2) close arterial infusion of vasopressinblocked the adaptive hyperemic response and abolished the adaptive cytoprotection; (3)intravenous indomethacin reduced the hasal GMBF, and abolished both the adaptive hyperemic response and cytoprotection; furthermore, the gross and deep damage were aggravated compared with that caused by high concentration alone. The results showedthat the adaptive hyperemic response of gastric mucosa was involved in the adaptive cytoprotection and suggested that the adaptive cytoprotection of endogenous prostaglandinmight be partially related to the increase of GMBF.