Background: Circulatory shock, especially endotoxin shock, is characterized by the release of a large number of mediators, among which proteases play a key role. The production of oxygen free radicals into the extracellular space and the increase of capillary permeability is one of the most important consequences of that phenomenon. In order to evaluate the efficacy of gabexate mesilate (Foy) in preventing such increase of microvascular permeability, an experimental model of endotoxin shock was used.
Materials and methods: Experiments were performed on the mesocecum of male Wistars rats, fluorescent labeled bovine albumine was injected intrarterially to evaluate the capillary permeability and the mesocecum microcirculation was observed by fluorescent light. The control group received saline i.v.; the II group received a DL 100 of E. coli endotoxin (DIFCO 0111: B4); the III and the IV group received a continuous infusion or topical application of gabexate mesilate respectively, before the administration of endotoxin. To evaluate capillary permeability and to quantify the degree of extravasion by counting the number of leaky sites, fluorescent labelled bovine albumin was injected i.v. and mesocecum was observed with fluorescent microscopy for 2 hours.
Results and conclusions: Capillary permeability did not increase in control rats; it largely increased in rats receiving endotoxin i.v. but it did not almost increased in rats receiving gabexate mesilate (Foy) that prevents the increase of capillary permeability that was observed in the group treated with endotoxin alone.