The authors described the results from a study on immonoreactive insuline in rats after their irradiation in the region of the pancreas with rubine laser with beam energy of 0, 13 Joul/impulse. The irradiation was made singly with 7--10 impulses. The level of immunoreactive insulin was raised to 33,83 microliter I/ml in nonirradiated rats and to 48 microliter/ml per 24 hours after irradiation and reached its maximum of 54 microliter/ml after 48 hours of its irradiation, but then returned to its normal values after 72 hours. The same elevation of insulin was found also in rats, irradiated in the region of liver, kidney and heart. The discovered histomorphologic findings in the tissues after irradiation revealed activation of mesenchyme, interpreted as a reaction of dystrophic changes, caused by laser beams. The elevation of insuline was connected with changes in hypophysial-adrenal system, presenting the type of the general adaptation syndrome, and, on the second place, site of the realesed mediators (sympathycomymetics) in this stress reaction.