In vivo microscopy of the gastric microcirculation

A method for observing the gastric microcirculation directly in the living animal and the results of its application to the study of the rat gastric microcirculation are described. The exteriorized stomach of an anesthetized rat was transilluminated by a cool light transmitted from a high intensity light source by means of a quartz rod. Illumination was adequate for direct microscopic visualization of blood flow through the muscle layer. After a portion of muscle and serosa had been dissected carefully, blood flow could be traced through the rich submucosal network of arterioarterial anastamoses down to the mucosa and back through collecting veins, emerging from the mucosa to the submucosal venovenous anastamotic network. By everting and transilluminating the exteriorized stomach, the superficial mucosa was visualized and blood flow could be traced through the hexagonally distributed capillaries surrounding the gastric glands to the collecting veins. The distribution of vessels in each of these layers is described in detail. Despite a careful search, no arteriovenous anastamoses were found, either in the submucosa or in the superficial mucosa.Supported by Veterans Administration research funds and a grant from the Orange County Heart Association.