1999 Fiscal Year Final Research Report Summary

CARBON DIOXIDE POISONING AND THE MECHANISM

Research Project

Project/Area Number	10671436
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Anesthesiology/Resuscitation studies
Research Institution	IBARAKI PREFECTURAL UNIVERSITY OF HEALTH
Principal Investigator	TAKESHIMA Reiko IBARAKI PREFECTURAL UNIVERSITY OF HEALTH SCIENTISTS, ASSISTANT PROFESSOR, 保健医療学部, 講師 (30188180)
Co-Investigator(Kenkyū-buntansha)	NAITO Hiroshi IBARAKI PREFECTURAL UNIVERSITY OF HEALTH SCIENTISTS, PROFESSOR, 保健医療学部, 教授 (60045341)
Project Period (FY)	1998 – 1999
Keywords	CARBON DIOXIDE / POISONING / RESPIRATION
Research Abstract	The purpose of this study is to establish the carbon dioxide (COィイD22ィエD2) toxicity, make clear the toxicological effects and the toxic mechanisms. (1) The lethal dose of 50% (LDィイD250ィエD2) in mouse [METHODS] Mice were exposure at any COィイD22ィエD2 concentration in the grass chamber for ten minutes. [RESULTS] LDィイD250ィエD2 was 35-40% COィイD22ィエD2 in 21% oxygen, 25% COィイD22ィエD2 in 15% OィイD22ィエD2, 20-25% COィイD22ィエD2 in 10% OィイD22ィエD2, 5-10% COィイD22ィエD2 in 8% OィイD22ィエD2. (2) The activity of mouse [METHODS] We determined activity for 10 min using AUTOMEX II. [RESULTS] (1) The activity compared with in air were decreased 45±11% in 5%COィイD22ィエD2 and 21%OィイD22ィエD2. They were deceased 25±11% in 10%COィイD22ィエD2, 23±11% in 15%COィイD22ィエD2, 7±6% in 20%COィイD22ィエD2, respectively. In 15%OィイD22ィエD2, they were deceased 62±16% in 5%COィイD22ィエD2, 32±14% in 10%COィイD22ィエD2, 15±7% in 15%COィイD22ィエD2, 6±5% in 20%COィイD22ィエD2, respectively. (2) We observed convulsion of mice over 35%COィイD22ィエD2 in 21%OィイD22ィエD2, over 20%COィイD22ィエD2 in 10-15%OィイD22ィエD2, over 5%COィイD22ィエD2 in 8%OィイD22ィエD2, respectively. (3) The changes of respiration in rats [METHODS] We measured the changes of respiratory rates at each COィイD22ィエD2 concentration under 21%OィイD22ィエD2. [RESULTS] The changes were 98±26% after 4 min (4 min), 114±37% (7 min), 85±21% (10 min) in 5% COィイD22ィエD2. They were 74±26% (4 min), 56±17% (7 min) 52±26% (10 min) in 10%COィイD22ィエD2. They were 96±17% (4 min), 101±30% (7 min), 112±39% (10 min) in 20%COィイD22ィエD2. They were 90±16% (4 min), 105±39% (7 min), 99±34% (10 min) 30%COィイD22ィエD2. They were 63±6% (4 min), 62±32% (7 min), 52±35% (10 min) in 40%COィイD22ィエD2. We are planing to study the clearly of the work of respiratory center in COィイD22ィエD2 toxicity.