Sakai T, Yoshida H, Fukui A, Takaori M
Department of Anesthesiology, Kawasaki Medical School, Japan.
Drug Metab Dispos. 1991 Mar-Apr;19(2):419-22.
To determine the urinary and biliary excretion of metabolites of halothane in dogs, 12 beagles were anesthetized with halothane either at 0.5 MAC (minimum alveolar concentration) for 1 hr or at 1.4 MAC for 4 hr. Urine and bile were then collected for 11 days following the anesthesia. The concentrations of inorganic fluoride in the urine and bile were measured with a fluoride electrode and an ion meter. The concentration of total fluoride containing organic fluoride also was measured in the same manner after conversion of the organic fluoride to an inorganic form by combustion. The concentration of trifluoroacetic acid (TFA) in the urine was measured by ion chromatography and that in the bile by gas chromatography. Over 80% of all the fluoride was excreted in the urine as organic fluoride in both groups. While the fraction of TFA in the organic fluoride in the bile was about 30% in both groups, that in the urine was 40% in the 0.5 MAC group and 65% in the 1.4 MAC group. Therefore, it was concluded that the organic fluoride compounds, the metabolites of halothane, and in particular TFA, were excreted mostly into the urine. The extent of metabolism of halothane decreased from 7.6% in the 0.5 MAC group to 4.9% in the 1.4 MAC group. The urinary excretion rate of TFA, however, was not affected by the concentration of inspired halothane.
为测定氟烷代谢产物在犬体内的尿液和胆汁排泄情况，将12只比格犬用氟烷麻醉，分别在0.5倍最低肺泡浓度（MAC）下麻醉1小时或在1.4倍MAC下麻醉4小时。麻醉后接下来的11天收集尿液和胆汁。用氟离子电极和离子计测量尿液和胆汁中无机氟的浓度。通过燃烧将有机氟转化为无机形式后，也以同样的方式测量含总氟的有机氟浓度。尿液中三氟乙酸（TFA）的浓度通过离子色谱法测量，胆汁中TFA的浓度通过气相色谱法测量。在两组中，超过80%的氟以有机氟的形式经尿液排泄。两组胆汁中有机氟中TFA的比例均约为30%，而尿液中，0.5倍MAC组为40%，1.4倍MAC组为65%。因此，得出结论：氟烷的代谢产物有机氟化合物，尤其是TFA，大多经尿液排泄。氟烷的代谢程度从0.5倍MAC组的7.6%降至1.4倍MAC组的4.9%。然而，TFA的尿液排泄率不受吸入氟烷浓度的影响。
