Engelking L R, Dodman N H, Hartman G, Valdez H, Spivak W
Am J Vet Res. 1984 Apr;45(4):607-15.
Effects of halothane anesthesia were investigated in ponies prepared surgically with chronic external biliary fistulas (T tubes) to determine the effects on liver function and biliary excretion during 2 hours of anesthesia. Four studies were performed on 2 ponies, 2 to 6 months after surgery with the enterohepatic circulation held intact between studies. Intravenous bile acid infusion was used to maintain steady-state bile flow, bilirubin, and bile acid excretion during each study. Compared with the immediate 2-hour preanesthesia values (base line), halothane caused a 138% increase in bilirubin excretion, a 60% increase in biliary bilirubin concentration, and a 43% increase in PCV. Halothane anesthesia also caused a 16% reduction in plasma bilirubin, a 46% reduction in biliary bile acid concentration, and a 27% reduction in bile acid excretion. The bile acid independent fraction of bile flow appeared to increase. Plasma aspartate transaminase concentration did not change during anesthesia. The ratio of conjugated bilirubin fractions in bile [82% to 83% disconjugates of glucuronide and glucoside (2 forms) and 17% to 18% monoconjugates of glucoside, glucuronide, and xyloside] did not change during anesthesia and less than 1% was excreted unconjugated. Halothane anesthesia did not appear to affect adversely the activity of the transferase-conjugating enzymes in the presence of an increased bilirubin load. Seemingly, greatly increased conjugated bilirubin excretion observed during halothane anesthesia was most likely the result of a combination of increased hepatic clearance from plasma and increased hepatic bilirubin production from turnover of free hepatic heme or heme from the induced cytochrome P-450 system.(ABSTRACT TRUNCATED AT 250 WORDS)
在通过外科手术制备了慢性外部胆管瘘（T形管）的小马身上研究了氟烷麻醉的效果，以确定麻醉2小时期间对肝功能和胆汁排泄的影响。在2匹小马身上进行了4项研究，手术2至6个月后进行，且在各项研究之间保持肝肠循环完整。在每项研究期间，通过静脉输注胆汁酸来维持胆汁流量、胆红素和胆汁酸排泄的稳态。与麻醉前2小时的即时值（基线）相比，氟烷使胆红素排泄增加了138%，胆汁胆红素浓度增加了60%，红细胞压积增加了43%。氟烷麻醉还使血浆胆红素降低了16%，胆汁胆汁酸浓度降低了46%，胆汁酸排泄降低了27%。胆汁流量中不依赖胆汁酸的部分似乎增加了。麻醉期间血浆天冬氨酸转氨酶浓度没有变化。胆汁中结合胆红素部分的比例[葡萄糖醛酸和葡萄糖苷（2种形式）的82%至83%非结合物以及葡萄糖苷、葡萄糖醛酸和木糖苷的17%至18%单结合物]在麻醉期间没有变化，且未结合排泄的比例不到1%。在胆红素负荷增加的情况下，氟烷麻醉似乎并未对转移酶结合酶的活性产生不利影响。显然，氟烷麻醉期间观察到的结合胆红素排泄大幅增加很可能是血浆肝清除率增加以及游离肝血红素或诱导的细胞色素P - 450系统产生的血红素周转导致肝胆红素生成增加共同作用的结果。（摘要截短至250字）
