Wielandt A M, Pizarro M, Solis N, Arrese M, Accatino L
Departamento de Gastroenterología, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago.
Hepatology. 1993 Jul;18(1):179-87.
The effects of obstructive cholestasis on the activity of alkaline phosphatase have been extensively studied in serum and liver tissue. However, very little is known about the activity of this enzyme in the postcholestatic condition after relief of the biliary obstruction. The purpose of this study has been to characterize alkaline phosphatase activity in serum, liver and bile in the postcholestatic period and to relate it to changes in bile acid secretory rate. Serum activity and biliary secretory rates of alkaline phosphatase were markedly increased in rats subjected to a reversible obstructive cholestasis for 24 hr or 48 hr and progressively declined along the postcholestatic period to values not significantly different from those of control rats within 48 hr. A significant direct linear relationship between the biliary secretory rates of enzyme activity and bile salts was apparent both in cholestatic groups and in the control groups. The slope of the regression line (units of alkaline phosphatase secreted per micromole of bile salts) was 1.5-fold to 3-fold higher in cholestatic animals. Remarkably, a positive y-intercept of regression lines suggested that a significant fraction of the enzyme was secreted independently of bile salts; this fraction was 18-fold and 34-fold greater in 24-hr and 48 hr cholestatic rats, respectively, compared with that in controls. Sodium taurocholate administered intravenously, either as a bolus or as an infusion at increasing submaximal rates, resulted in parallel increases of bile salt and alkaline phosphatase secretory rates into bile. The enzyme activity secreted per micromole of taurocholate was significantly greater in cholestatic than in control rats.(ABSTRACT TRUNCATED AT 250 WORDS)
阻塞性胆汁淤积对血清和肝组织中碱性磷酸酶活性的影响已得到广泛研究。然而，对于胆道梗阻解除后胆汁淤积状态下该酶的活性却知之甚少。本研究的目的是对胆汁淤积后期血清、肝脏和胆汁中的碱性磷酸酶活性进行表征，并将其与胆汁酸分泌率的变化相关联。在经历24小时或48小时可逆性阻塞性胆汁淤积的大鼠中，碱性磷酸酶的血清活性和胆汁分泌率显著增加，并在胆汁淤积后期逐渐下降，在48小时内降至与对照大鼠无显著差异的值。在胆汁淤积组和对照组中，酶活性的胆汁分泌率与胆盐之间均存在显著的直接线性关系。胆汁淤积动物的回归线斜率（每微摩尔胆盐分泌的碱性磷酸酶单位）比对照组高1.5倍至3倍。值得注意的是，回归线的正y轴截距表明，相当一部分酶的分泌独立于胆盐；与对照组相比，24小时和48小时胆汁淤积大鼠中的这一比例分别高出18倍和34倍。静脉注射牛磺胆酸钠，无论是大剂量注射还是以逐渐增加的亚最大速率输注，都会导致胆汁中胆盐和碱性磷酸酶分泌率的平行增加。每微摩尔牛磺胆酸盐分泌的酶活性在胆汁淤积大鼠中显著高于对照大鼠。（摘要截短至250字）
