THE EFFECT OF THYROTROPIN-RELEASING-HORMONE ON CARBON-DIOXIDE LASER-INDUCED LESION OF THE CEREBRAL-ARTERY

Carbon dioxide laser which is used widely in neurosurgery has less tra umatic effect on the tissue beside the lesion than other types of lase r. There has been little study on the changes to the vascular tissue, following laser application. We performed a study on 4 goups of dogs; comprising craniectomy only, craniectomy and thyrotropin releasing hor mone (TRH), craniectomy and laser, and craniectomy, laser and TRH. We applied CO2 laser on the angular artery of two groups of dogs. To one group we infused TRH for 15 days following the laser application and t o the other group we did not. We investigated the ultrastructural and biochemical changes and the effect of TRH on the tissue 15 days follow ing laser application. In our study, we observed an increase in supero xide dismutase activity and a decrease in ATP-ase activities in the de generated tissue on which CO2 laser was applied. TRH partially prevent ed the vascular degeneration of CO2 laser but did not significantly ch ange superoxide dismutase and Adenosine-5'-triphosphatase activities.