Hepatic Transport of Organic Substances

Hepatic cells are involved in the metabolization and elimination of a variety of endogenous and exogenous substances. They mediate the uptake, processing and subsequent secretion of biliary compounds, such as various drugs or hormones, and the passage of metabolites to be released into different blood compartments. To perform vectorial passages hepatocytes show a strong polarity with sites for endocytotic processes or specific carrier molecules, and a specified system of organelles for intracellular transport and sorting, metabolization and secretion of compounds. Several aspects, e.g. regulation, control and mechanisms of hepatic traffic are reported in detail - complemented by methodological approaches to analyse and monitor these processes.

1 General Aspects of Hepatic Transport.- Glutamate-sodium Cotransport in the Kidney: An Example for the Plasticity of Transport Systems.- Energetic Coupling in Secondary Active Transport.- The Passage of Molecules into Bile: Paracellular and Transcytotic Pathways.- Increase in Paracellular Permeability as a Pathophysiological Principle of Drug-induced Intrahepatic Cholestasis in Rats.- The Hepatocyte’s Plasma Membrane Domains. Interrelations with the Endocytic Compartment.- Hepatic Spaces and Transport in the Perfused Liver.- New Methodologic Approaches for the Study of Transport in the Liver.- Transport Processes in Mammalian Gallbladder and Bile Duct.- Transcellular Butyrate Transport in Gallbladder Epithelium.- Accessibility of Primary Bile in Liver Cell Culture.- Polarity of the Hepatocyte Surface Membrane: Influence of Lipids on Protein Function.- ATP in and Around the Bile Canaliculus.- 2 Physiology, Pharmacology, and Biochemistry of Hepatic Transport Systems.- Hepatic Transport of Glutathione-Conjugates.- Glutathione Conjugate Transport in Hepatic Elimination of Electrophiles.- Hepatobiliary Cysteinyl Leukotriene Elimination.- Biliary Excretion of Thiols and Their Role in Elimination of Methylmercury.- Hepatic Transport of Amino Acids.- Glutamine and Glutamate Transport in Perfused Liver.- Regulation of Hepatic Amino Acid Transport and Partial Purification of the System A Carrier.- Hormonal Control of Amino Acid Transport Systems in Cultured Periportal and Perivenous Hepatocytes.- Differential Inactivation of System A in Normal and Transformed Liver Cells.- Mechanism of Renal Transport of L-Alanine in Luminal Membrane Vesicles.- Hepatic Transport of Organic Anions and Bile Acids.- Characteristics of Organic Anion Binding Proteins from Rat Liver SinusoidalPlasma Membranes.- Mechanism of Hepatic Fatty Acid Uptake.- Studies on the Mechanism of Organic Anion Transport by the Liver.- Mechanisms of Sinusoidal Bile Acid Transport.- Binding and Uptake of Taurocholate in Subcellular Organelles from Rat Liver.- The Ontogeny of Hepatic Bile Acid Transport.- Identification and Function of Bile Salt Binding Polypeptides of Hepatocyte Membrane.- Characterization of the Bile Acid Transport System in Normal and Transformed Hepatocytes Using Monoclonal Antibodies.- Transport of Bile Salts Across the Canalicular Plasma Membrane.- Biliary Taurocholate Excretion During the Metabolism of 2-Methyl-1, 4-Naphthoquinone (Menadione) in Perfused Rat Liver.- Comparison of Bile Salt-Binding Proteins in Basolateral Membranes from Small Intestine, Kidney, and Liver.- Effects of Hydrostatic Pressure and Liver Cell Membrane Potential on Hepatic Bile Acid Transport.- Characterization and Purification of Bile Acid Transport Proteins.- Transport of Taurocholate in Isolated Cells from Ileum, Liver and Kidney.- Properties of the Taurocholate Uptake System in Basolateral Rat Liver Plasma Membrane Vesicles: Effects of Albumin and Substrate Specificity.- Hepatic Transport of Xenobiotics.- Uptake of Foreign Cyclopeptides by Liver Cells.- Identification of Carrier Proteins in Hepatocytes by (Photo) Affinity Labels Derived from Foreign Cyclopeptides.- Uptake of Xenobiotics by the Bile Acid Transport System in the Liver: Relationship Between the Organic Anion Transport Systems in the Kidney and the Liver.- Mechanisms for Hepato-Bi1iary Transport of Cationic Drugs Studied with the Intact Organ and on the Membrane Level.- The Role of Liver and Extrahepatic Organs in the Metabolism of N-Nitrosodibutylamine (NDBA): Comparison of in Vitro with in Vivo Data.- The Roleof Biliary Excretion and Intestinal Metabolism for Toxokinetics and Toxicity of T-2 Toxin, a Major Trichothecene Mycotoxin.- Binding Proteins for Dipeptides, ?-Lactam Antibiotics, and p-Aminohippurate (PAH) in Plasma Membranes from Small Intestine and Kidney.- Hepatic Transport of Hormones.- Transport Properties of Steroid Glucuronides.- Intestinal Transport of Glucuronides and Sulphoconjugates.- Transport of Thyroid Hormone (TH) into Hepatocytes.- Metabolism of Thyroid Hormone in Liver.- Concluding Remarks.