EFFECTS OF MODULATED MICROWAVE AND X-RAY-IRRADIATION ON THE ACTIVITY AND DISTRIBUTION OF CA2-ATPASE IN SMALL-INTESTINE EPITHELIAL-CELLS()

The distribution and activity of Ca2+-ATPase were investigated by hist ochemical methods in small intestine epithelial cells of mice followin g total body 2450 MHz low frequency (16 Hz) microwave and X-ray irradi ation. In the control animals, enzyme activities were found in the bru sh border and on lateral membranes, including junctional areas of the cells. The enzyme activity of lateral membranes was inhibited by querc etin, a specific inhibitor of Ca2+-ATPase. Immediately after square mo dulated (16 Hz) 2450 MHz microwave irradiation at 1 mW/cm(2) power den sities, we observed a decreased activity of Ca2+-ATPase on the lateral membrane regions. The X-ray irradiation (1 Gy) induced a similar decr ease of Ca2+-ATPase activity which was reversible within 24 hours. ''5 Gy'' doses resulted in a decrease of enzyme activities on both apical and lateral membrane areas persisting up to 24 hours following irradi ation.