Hepatocyte cotransport of taurocholate and bilirubin glucuronides: Role of microtubules

Journal Article · Fri Jul 01 04:00:00 EDT 1988 · American Journal of Physiology; (USA)

OSTI ID:6834461

Crawford, J M; Gollan, J L ^[1]

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1. Harvard Medical School, Boston, MA (USA)

Modulation of bile pigment excretion by bile salts has been attributed to modification of canalicular membrane transport or a physical interaction in bile. Based on the observation that a microtubule-dependent pathway is involved in the hepatocellular transport of bile salts, the authors investigated the possibility that bilirubin glucuronides are associated with bile salts during intracellular transport. Experiments were conducted in intact rats (basal) or after overnight biliary diversion and intravenous reinfusion of taurocholate (depleted/reinfused). All rats were pretreated with intravenous low-dose colchicine or its inactive isomer lumicolchicine. Biliary excretion of radiolabeled bilirubin glucuronides derived from tracer ({sup 14}C)bilirubin-({sup 3}H)bilirubin monoglucuronide (coinjected iv) was unchanged in basal rats but was consistently delayed in depleted/reinfused rats. This was accompanied by a significant shift toward bilirubin diglucuronide formation from both substrates. In basal Gunn rats, with deficient bilirubin glucuronidation, biliary excretion of intravenous ({sup 14}C)bilirubin monoglucuronide-({sup 3}H)bilirubin diglucuronide was unaffected by colchicine but was retarded in depleted/reinfused Gunn rats. Colchicine had no effect on the rate of bilirubin glucuronidation in vitro in rat liver microsomes. They conclude that a portion of the bilirubin glucuronides generated endogenously in hepatocytes or taken up directly from plasma may be cotransported with bile salts to the bile canalicular membrane via a microtubule-dependent mechanism.

• OSTI ID: 6834461
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 255:1; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALOIDS
ANIMAL CELLS
ANIMALS
ANTIMITOTIC DRUGS
ANTIPYRETICS
AZOLES
BILE
BILIRUBIN
BIOLOGICAL MATERIALS
BODY FLUIDS
CARBON 14 COMPOUNDS
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM DEPRESSANTS
COLCHICINE
DRUGS
DUAL-ISOTOPE SUBTRACTION TECHNIQUE
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
LIVER CELLS
MAMMALS
MATERIALS
MEMBRANE TRANSPORT
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHYSIOLOGY
PIGMENTS
PYRROLES
RATS
RODENTS
SOMATIC CELLS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES