[Nd:YAG laser radiation alters the proteolytic resistance of the liver tissue proteins in rats].

Small tissue strips were excised from rat liver and exposed to extensive irradiation with Nd:YAG laser followed by homogenization and spectrophotometric detection of 5% TCA-soluble protein fractions (oligopeptides) in both supernatants and 5NKOH-soluble sediments of the irradiated specimens. Trypsin along, or with chemotrypsin was added to the specimens to evaluate their proteolytic resistance during and after incubation for 24 h in the proteinase(s). The results showed that Nd:YAG laser irradiation resulted in significantly more oligopeptides following either schedule of the proteolysis employed in both supernatants and sediments as compared to the unaffected proteolytically tested specimens. At the same time a proteolytically resistant 5% TCA-insoluble fraction was elicited which belonged to proteins and, judging by the parallel ultrastructural data, was located in the cellular membranes. The probable mechanisms of the observed protein modifications, along with some pertinent clinical implications of Nd:YAG laser surgery, are considered.