[Effect of the helium-neon laser on cell ultrastructure and proliferation of the epithelium of the duodenal mucosa].

Irradiation of the rat duodenal wall with helium-neon laser at a wave length of 0.63 microns for 1,3 and 5 min and irradiation energy density of 6.78, 20.34 and 33.9 J/cm2, respectively, produced ultrastructural changes in enterocytes and connective tissues. These changes consisted in intracellular edema and occurrence of cellular branches in basal portions and vesicles in apical portions of enterocytes. The changes increased as the irradiation energy was raised. Laser irradiation caused a significant rise of proliferative activity.