Oxygen free Radical Reactions by Various Partial Pressure of Oxygen in Rats intoxicated with Carbon Monoxide

Experiments, using CO intoxicated male Sprague-Dawley rats, were carried out (1) to see the change of the oxygen tree radical reaction according to partial pressure of oxygen, and (2) to assess the effectiveness of superoxide dismutase (SOD) activity, malondialdehyde (MDA), and ethane as a parameter of the reaction. Ethane was measured in exhaled breath anti SOD activity and MDA In brain tissue. Experimental group consist of (1) Control group (=breathing with air[ambient air]), (2) HBO group (=exposed to hyperbaric oxygen(HBO, 3ATA, l00%] after all breath), (3) CO-Air group (=exposed to CO [3,970 ppm] after air breath followed by air breath), (4) CO-HBO group (=exposed to CO after air breath followed by HBO treatment), and (5) CO group (=exposed to CO after air breath, only for SOD activity & MDA measuring). Amount of ethane exhaled during 30 minutes of HBO treatment after GO exposure was significantly greater than those of all the other groups (p-value= .002) , suggesting more oxygen free radical reaction is taken place in CO intoxicated rats treated with higher partial pressure of oxygen. The long-term follow-up studies are required to differentiate the adverse effects of HBO treatment from the sequelae of CO poisoning itself, and to develop the preventive measures for the adverse effect of HBO treatment. And there was no significnat difference among the five groups in SOD activity and MDA measuring (p-value>.05). This result may be accounted for the rapid recovery of SOD activity and the metabolic degradation and excretion of MDA in a short time. In conclusion, measurement of ethane in exhaled breath is more effective than those of SOD activity and MDA as a parameter to assess the oxygen free radical reaction produced by HBO treatment for CO poisoned rats as a whole

Protective Effects of the NMDA-receptor Antagonist (MK-801) for the Brain Injury by Oxygen Free Radical: In the Hyperbaric Oxygen Treatment of CO Poisoned Rat / 대한산업의학회지

The effects of NMDA-receptor antagonist (MK-801) were assessed for the oxygen free radical mediated brain (hippocampus) injury with eighty rats which were exposed to carbon monoxide (CO) followed by hyperbaric oxygen (HBO) treatment. Superoxide dismutase (SOD) and malondialdehyde (MDA) were used as parameters of the oxygen free radical reaction. Experimental groups consisted of (1) control group (=breathing with air), (2) CO group (=exposed to CO after air breath), (3) CO-air group(exposed to CO after air breath followed by air breath), and (4) CO-HBO group (=exposed to CO after air breath followed by 3 ATA HBO). Each group was divided two subgroup according to the pretreatment (normal saline or MK-801). CO, CO-air and HBO groups increased in SOD activity as compared with control group. And CO-air and HBO groups increased in MDA as compared with control and CO group. Pretreatment of MK-801 decreased SOD activities significantly (p-value<.05) , but MDA amount not significantly (p-value=.107). These results suggest a useful protective effect of NMDA-receptor antagonist (MK-801) in CO induced hippocampal injury mediated by oxygen free radicals.