[The Na, K-ATPase activity of the separate structural components of the guinea-pig visual system in hypoxia]

Different degree of sensitivity to acute hypoxia in vivo has been shown in guinea-pig pigmented epithelium, retina and visual cortex Na, K-ATPase. The highest degree of the enzyme activity inhibition has been noted in the pigmented epithelium (more than 3 times), lower inhibition-in visual cortex (26%) and the lowest-in the retina (18%). In contrast to Na, K-ATPase, hypoxia effect on Mg-ATPase resulted in both inhibition and activation of the enzyme in all 3 structures. Reoxygenation following acute hypoxia increases Na, K-ATPase activity inhibition in the retina and visual cortex. But under reoxygenation the enzyme activity is recovered in the pigmented epithelium. Preliminary administrations of vitamin E completely prevented Na, K-ATPase activity inhibition in all studied structures.