HISTOCHEMICAL-CHARACTERISTICS OF CEREBRAL CAPILLARY BED DURING EXPOSURE TO LOW-INTENSITY LASER

Rat brain was exposed to He-Ne laser at wavelength 632.8 nm, power den sity 0.76 mWt/cm2. Hippocampal capillaries detected by alkaline phosph atase were examined in various periods (from 1 sec to 3 h) after the e xposure. Changes of the enzyme activity in capillary walls, capillary length and diameter were examined after laser exposures of various dur ation. Enzymic activity and total capillary length were found to incre ase within the first 15 min of irradiation by 1.5-2 times. A longer ir radiation resulted in reduction of these parameters. Capillary diamete r changed negligibly after 15-min exposure, and after a longer irradia tion a stable dilatation of capillaries was observed.