Experimental Studies on Oxygen Tolerance and Poisoning under Hyperbaric Oxygen Environment

고압산소환경(高壓酸素環境)에서의 산소중독(酸素中毒) 및 내성(耐性)에 관(關)한 실험적(實驗的) 연구(硏究)

Experimental studies were performed to observe the difference in tolerance of small animals to oxygen poisoning, and also to examine the effects of certain drug for it. The three experimental groups consisted of mature rat group, immature rat group and mouse group. The animals were exposed to 5 atm. of 100% oxygen using hyperbaric chamber, and they were observed for oxygen poisoning by pulmonary and central nervous system manifestation. The tolerance to oxygen poisoning was represented by half fatality time in each experimental group. The drug applied was ammonium chloride $NH_4Cl$ and it was administered intraperitoneally in various dosages for particular attribution of its prophylactic effect. The following conclusions were made; 1. The immature rat group showed the higher degree of tolerance to oxygen poisoning, as evidenced by a more prolonged half fatality time in the group. No significant difference in the half fatality time between the mature rat and the mouse group was observed. 2. The fact that the immature group showed the higher degree of tolerance as compared with the mature rat group represented by delayed onset of convulsion. 3. There was a remarkable difference in the Lung Weight/Body Weight ratio between the experimental and control group. 4. The animals with a shorter half fatality time uniformally displayed an earlier onset of convulsive seizure as the sign of oxygen poisoning and a significant elevated Lung Weight/Body Weight ratio. 5. Ammonium chloride at the dosage of 450mg per kg body weight had the most pronounced prophylactic effect on oxygen poisoning.