Roma M G, Luque E A, Marinelli R A, Rodrguez Garay E A
Instituto de Fisiología Experimental, Universidad Nacional de Rosario, Argentina.
Biochem Pharmacol. 1989 Nov 15;38(22):4021-5. doi: 10.1016/0006-2952(89)90682-5.
Biliary solute concentrations measured at the tip of the cannula suffer a delay with respect to bile flow due to the transit time through the biliary tree volume. This study proposes a simple method, which is valid under variable bile flow conditions, to correct the distortion introduced by the biliary tree volume on the kinetic curves of the biliary excretion rate. The biliary transit time (tt) was calculated as the time needed to excrete a bile volume equal to the biliary tree volume by means of the interpolation of biliary cumulative volume versus time curves. Such tt permits one to estimate the canalicular concentration at time t, interpolating the biliary concentration curves at time t-tt. The product between the estimated canalicular concentration and the bile flow allows the calculation of the corrected biliary excretion rate. This method was evaluated by a comparison between biliary excretion rate curves of [14C]taurocholate [( 14C]TC) injected as a bolus under basal and sodium dehydrocholate (DHC)-induced choleresis conditions. Since the canalicular excretion rate of [14C]TC is considered independent of bile flow, the significant differences observed in its excretion kinetics under both conditions were attributed to distortion due to the biliary tree volume. After the correction, both curves showed a significant overlapping. This result indicates that the method improves the time-course representation of canalicular events in biliary excretion kinetic studies.
由于胆汁流经胆管系统容积需要一定时间，在插管尖端测得的胆汁溶质浓度相对于胆汁流动存在延迟。本研究提出了一种简单的方法，该方法在胆汁流量可变的条件下有效，用于校正胆管系统容积对胆汁排泄率动力学曲线造成的失真。胆汁通过时间（tt）通过胆汁累积体积与时间曲线的插值计算得出，即排泄与胆管系统容积相等的胆汁体积所需的时间。利用该tt值，通过在时间t - tt对胆汁浓度曲线进行插值，可估算出时间t时的胆小管浓度。估算的胆小管浓度与胆汁流量的乘积可用于计算校正后的胆汁排泄率。通过比较在基础状态下和脱氢胆酸钠（DHC）诱导胆汁分泌条件下推注注射的[14C]牛磺胆酸盐[（14C）TC]的胆汁排泄率曲线，对该方法进行了评估。由于[14C]TC的胆小管排泄率被认为与胆汁流量无关，在两种条件下观察到的其排泄动力学的显著差异归因于胆管系统容积造成的失真。校正后，两条曲线显示出明显的重叠。这一结果表明，该方法改善了胆汁排泄动力学研究中胆小管事件的时间进程表示。
