Kumagai S, Oda H, Matsunaga I, Kosaka H, Akasaka S
Department of Occupational Health, Osaka Prefectural Institute of Public Health, Japan.
Toxicol Sci. 1999 Apr;48(2):255-63. doi: 10.1093/toxsci/48.2.255.
Respiratory uptake was investigated for 10 polar organic solvents with high blood/air partition coefficients (lambda(blood/air)): ethyl acetate (lambda(blood/air), 77), methyl iso-butyl ketone (90), methyl acetate (90), methyl propyl ketone (150), acetone (245), iso-pentyl alcohol (381), iso-propyl alcohol (848), methyl alcohol (2590), ethylene glycol monobutyl ether (EGBE, 7970), and propylene glycol monomethyl ether (PGME, 12380). Test-air concentrations (Cinh) were 25 to 200 ppm. Four healthy male volunteers inhaled the test air for 10 min at rest and then room air for 5 min. The percentage of solvent in the end-exhaled air and in the mixed-exhaled air increased after the start of the test-air respiration, and reached a quasi-steady-state level within a few min. The speeds of these increases at the start of the test-air respiration became lower as lambda(blood/air) increased. The mean uptakes (U) for the last five min of the test air respiration were 67.3, 52.9, 60.4, 53.0, 52.6, 63.0, 60.3, 60.8, 79.7, and 81.3%, respectively, for ethyl acetate, methyl iso-butyl ketone, methyl acetate, methyl propyl ketone, acetone, iso-pentyl alcohol, iso-propyl alcohol, methyl alcohol, EGBE and PGME. Thus, U values of the alcohols were higher than those of the ketones and lower than the glycol ethers. The overall view, except for esters, showed that U increased with lambda(water/air) increases. This tendency can be explained by a hypothesis that solvent absorbed in the mucus layer of the respiratory tract is removed by the bronchial blood circulation. U values of ethyl acetate and methyl acetate were higher than those of methyl iso-butyl ketone and methyl propyl ketone, though the lambda(blood/air) values of these esters were nearly equal to those of the ketones. For the respiration of the esters, their metabolites, ethyl alcohol and methyl alcohol, were detected in the exhaled air. The exhalation percentage of the metabolites increased after the start of test-air respiration and reached a quasi-steady-state level of 2 and 3%, respectively, by the 5th min. These data suggest that removal of the solvent via metabolism in the wall tissue of the respiratory tract plays an important role for the esters.
研究了10种具有高血/气分配系数（λ（血/气））的极性有机溶剂的呼吸道摄取情况：乙酸乙酯（λ（血/气），77）、甲基异丁基酮（90）、乙酸甲酯（90）、甲基丙基酮（150）、丙酮（245）、异戊醇（381）、异丙醇（848）、甲醇（2590）、乙二醇单丁醚（EGBE，7970）和丙二醇单甲醚（PGME，12380）。测试空气中的浓度（Cinh）为25至200 ppm。4名健康男性志愿者在静息状态下吸入测试空气10分钟，然后吸入室内空气5分钟。在开始呼吸测试空气后，终末呼出气体和混合呼出气体中溶剂的百分比增加，并在几分钟内达到准稳态水平。随着λ（血/气）的增加，在开始呼吸测试空气时这些增加的速度降低。在呼吸测试空气的最后五分钟内，乙酸乙酯、甲基异丁基酮、乙酸甲酯、甲基丙基酮、丙酮、异戊醇、异丙醇、甲醇、EGBE和PGME的平均摄取量（U）分别为67.3%、52.9%、60.4%、53.0%、52.6%、63.0%、60.3%、60.8%、79.7%和81.3%。因此，醇类的U值高于酮类，低于二醇醚类。总体而言，除酯类外，U值随λ（水/气）的增加而增加。这种趋势可以用一种假设来解释，即呼吸道黏液层中吸收的溶剂通过支气管血液循环被清除。乙酸乙酯和乙酸甲酯的U值高于甲基异丁基酮和甲基丙基酮，尽管这些酯类的λ（血/气）值与酮类几乎相等。对于酯类的呼吸，在呼出气体中检测到了它们的代谢产物乙醇和甲醇。在开始呼吸测试空气后，代谢产物的呼出百分比增加，并在第5分钟时分别达到2%和3%的准稳态水平。这些数据表明，通过呼吸道壁组织中的代谢作用清除溶剂对酯类起着重要作用。
