Barnhart J L, Combes B
Am J Physiol. 1976 Aug;231(2):399-407. doi: 10.1152/ajplegacy.1976.231.2.399.
A comparison of the maximal rates of biliary excretion (Tm), of dye in dogs infused with either BSP or its glutathione conjugate (BSP-GSH) was carried out. Tm was much higher when BSP-GSH rather than BSP was infused. This was accounted for by a significantly higher concentration of dye in bile of dogs receiving BSP-GSH. Evidence is presented that BSP and its conjugated metabolites compete for a common transport carrier and that BSP disproportionately depresses the biliary excretion of conjugated dye compounds. This latter observation accounts for the depressed dye Tm found during infusion of BSP. Choleresis invariably accompanied dye excretion. When BSP-GSH was infused, enhanced bile flow could be accounted for by the predicted osmotic activity of dye transported into bile. By contrast, the choleresis measured during infusion of BSP was significantly greater than that predicted. An additional mechanism for choleresis is operative, therefore, when unconjugated BSP is infused. Administration of taurocholate enhanced dye Tm when BSP-GSH was infused. Since increments of canalicular bile flow induced by theophylline and glucagon did not enhance dye excretion into bile, this effect by taurocholate appears to be related to taurocholate excretion per se rather than to the enhanced canalicular bile flow which accompanies its excretion.
对输注磺溴酞（BSP）或其谷胱甘肽共轭物（BSP - GSH）的犬的胆汁排泄最大速率（Tm）进行了染料比较。输注BSP - GSH时的Tm比输注BSP时高得多。这是由于接受BSP - GSH的犬胆汁中染料浓度显著更高所致。有证据表明，BSP及其共轭代谢物竞争共同的转运载体，且BSP不成比例地抑制共轭染料化合物的胆汁排泄。后一观察结果解释了输注BSP期间发现的染料Tm降低的原因。胆汁分泌总是伴随着染料排泄。输注BSP - GSH时，胆汁流量增加可归因于转运至胆汁中的染料预期的渗透活性。相比之下，输注BSP期间测得的胆汁分泌显著大于预期。因此，输注未共轭的BSP时，存在另一种胆汁分泌机制。输注BSP - GSH时，牛磺胆酸盐的给药增强了染料Tm。由于茶碱和胰高血糖素诱导的胆小管胆汁流量增加并未增强染料向胆汁中的排泄，牛磺胆酸盐的这种作用似乎与其本身的排泄有关，而非与其排泄时伴随的胆小管胆汁流量增加有关。
