Liver Circulation: The circulation of BLOOD through the LIVER.Liver Diseases: Pathological processes of the LIVER.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Liver Transplantation: The transference of a part of or an entire liver from one human or animal to another.Liver Neoplasms: Tumors or cancer of the LIVER.Liver Cirrhosis: Liver disease in which the normal microcirculation, the gross vascular anatomy, and the hepatic architecture have been variably destroyed and altered with fibrous septa surrounding regenerated or regenerating parenchymal nodules.Blood Circulation: The movement of the BLOOD as it is pumped through the CARDIOVASCULAR SYSTEM.Microsomes, Liver: Closed vesicles of fragmented endoplasmic reticulum created when liver cells or tissue are disrupted by homogenization. They may be smooth or rough.Liver Regeneration: Repair or renewal of hepatic tissue.Fatty Liver: Lipid infiltration of the hepatic parenchymal cells resulting in a yellow-colored liver. The abnormal lipid accumulation is usually in the form of TRIGLYCERIDES, either as a single large droplet or multiple small droplets. Fatty liver is caused by an imbalance in the metabolism of FATTY ACIDS.Extracorporeal Circulation: Diversion of blood flow through a circuit located outside the body but continuous with the bodily circulation.Liver Function Tests: Blood tests that are used to evaluate how well a patient's liver is working and also to help diagnose liver conditions.Mitochondria, Liver: Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)Pulmonary Circulation: The circulation of the BLOOD through the LUNGS.Drug-Induced Liver Injury: A spectrum of clinical liver diseases ranging from mild biochemical abnormalities to ACUTE LIVER FAILURE, caused by drugs, drug metabolites, and chemicals from the environment.Liver Extracts: Extracts of liver tissue containing uncharacterized specific factors with specific activities; a soluble thermostable fraction of mammalian liver is used in the treatment of pernicious anemia.Liver Neoplasms, Experimental: Experimentally induced tumors of the LIVER.Collateral Circulation: Maintenance of blood flow to an organ despite obstruction of a principal vessel. Blood flow is maintained through small vessels.Liver Failure, Acute: A form of rapid-onset LIVER FAILURE, also known as fulminant hepatic failure, caused by severe liver injury or massive loss of HEPATOCYTES. It is characterized by sudden development of liver dysfunction and JAUNDICE. Acute liver failure may progress to exhibit cerebral dysfunction even HEPATIC COMA depending on the etiology that includes hepatic ISCHEMIA, drug toxicity, malignant infiltration, and viral hepatitis such as post-transfusion HEPATITIS B and HEPATITIS C.Liver Abscess: Solitary or multiple collections of PUS within the liver as a result of infection by bacteria, protozoa, or other agents.Liver Diseases, Alcoholic: Liver diseases associated with ALCOHOLISM. It usually refers to the coexistence of two or more subentities, i.e., ALCOHOLIC FATTY LIVER; ALCOHOLIC HEPATITIS; and ALCOHOLIC CIRRHOSIS.Enterohepatic Circulation: Recycling through liver by excretion in bile, reabsorption from intestines (INTESTINAL REABSORPTION) into portal circulation, passage back into liver, and re-excretion in bile.Hepatocytes: The main structural component of the LIVER. They are specialized EPITHELIAL CELLS that are organized into interconnected plates called lobules.Hepatectomy: Excision of all or part of the liver. (Dorland, 28th ed)Coronary Circulation: The circulation of blood through the CORONARY VESSELS of the HEART.Cerebrovascular Circulation: The circulation of blood through the BLOOD VESSELS of the BRAIN.Liver Cirrhosis, Experimental: Experimentally induced chronic injuries to the parenchymal cells in the liver to achieve a model for LIVER CIRRHOSIS.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Liver Cirrhosis, Alcoholic: FIBROSIS of the hepatic parenchyma due to chronic excess ALCOHOL DRINKING.Splanchnic Circulation: The circulation of blood through the BLOOD VESSELS supplying the abdominal VISCERA.Placental Circulation: The circulation of BLOOD, of both the mother and the FETUS, through the PLACENTA.Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.Liver, Artificial: Devices for simulating the activities of the liver. They often consist of a hybrid between both biological and artificial materials.Liver Glycogen: Glycogen stored in the liver. (Dorland, 28th ed)Alanine Transaminase: An enzyme that catalyzes the conversion of L-alanine and 2-oxoglutarate to pyruvate and L-glutamate. (From Enzyme Nomenclature, 1992) EC, Hepatocellular: A primary malignant neoplasm of epithelial liver cells. It ranges from a well-differentiated tumor with EPITHELIAL CELLS indistinguishable from normal HEPATOCYTES to a poorly differentiated neoplasm. The cells may be uniform or markedly pleomorphic, or form GIANT CELLS. Several classification schemes have been suggested.Blood Circulation Time: Determination of the shortest time interval between the injection of a substance in the vein and its arrival at some distant site in sufficient concentration to produce a recognizable end result. It represents approximately the inverse of the average velocity of blood flow between two points.End Stage Liver Disease: Final stage of a liver disease when the liver failure is irreversible and LIVER TRANSPLANTATION is needed.Tissue Distribution: Accumulation of a drug or chemical substance in various organs (including those not relevant to its pharmacologic or therapeutic action). This distribution depends on the blood flow or perfusion rate of the organ, the ability of the drug to penetrate organ membranes, tissue specificity, protein binding. The distribution is usually expressed as tissue to plasma ratios.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Kinetics: The rate dynamics in chemical or physical systems.Perfusion: Treatment process involving the injection of fluid into an organ or tissue.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.RNA, Messenger: RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.Regional Blood Flow: The flow of BLOOD through or around an organ or region of the body.Portal Vein: A short thick vein formed by union of the superior mesenteric vein and the splenic vein.Kupffer Cells: Specialized phagocytic cells of the MONONUCLEAR PHAGOCYTE SYSTEM found on the luminal surface of the hepatic sinusoids. They filter bacteria and small foreign proteins out of the blood, and dispose of worn out red blood cells.Hepatitis: INFLAMMATION of the LIVER.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Kidney: Body organ that filters blood for the secretion of URINE and that regulates ion concentrations.Carbon Tetrachloride: A solvent for oils, fats, lacquers, varnishes, rubber waxes, and resins, and a starting material in the manufacturing of organic compounds. Poisoning by inhalation, ingestion or skin absorption is possible and may be fatal. (Merck Index, 11th ed)Fetus: The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.Bile: An emulsifying agent produced in the LIVER and secreted into the DUODENUM. Its composition includes BILE ACIDS AND SALTS; CHOLESTEROL; and ELECTROLYTES. It aids DIGESTION of fats in the duodenum.Cytochrome P-450 Enzyme System: A superfamily of hundreds of closely related HEMEPROTEINS found throughout the phylogenetic spectrum, from animals, plants, fungi, to bacteria. They include numerous complex monooxygenases (MIXED FUNCTION OXYGENASES). In animals, these P-450 enzymes serve two major functions: (1) biosynthesis of steroids, fatty acids, and bile acids; (2) metabolism of endogenous and a wide variety of exogenous substrates, such as toxins and drugs (BIOTRANSFORMATION). They are classified, according to their sequence similarities rather than functions, into CYP gene families (>40% homology) and subfamilies (>59% homology). For example, enzymes from the CYP1, CYP2, and CYP3 gene families are responsible for most drug metabolism.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Blood Flow Velocity: A value equal to the total volume flow divided by the cross-sectional area of the vascular bed.Dogs: The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)Portal System: A system of vessels in which blood, after passing through one capillary bed, is conveyed through a second set of capillaries before it returns to the systemic circulation. It pertains especially to the hepatic portal system.Hemodynamics: The movement and the forces involved in the movement of the blood through the CARDIOVASCULAR SYSTEM.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Organ Size: The measurement of an organ in volume, mass, or heaviness.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Hepatic Artery: A branch of the celiac artery that distributes to the stomach, pancreas, duodenum, liver, gallbladder, and greater omentum.Bile Ducts: The channels that collect and transport the bile secretion from the BILE CANALICULI, the smallest branch of the BILIARY TRACT in the LIVER, through the bile ductules, the bile ducts out the liver, and to the GALLBLADDER for storage.Vascular Resistance: The force that opposes the flow of BLOOD through a vascular bed. It is equal to the difference in BLOOD PRESSURE across the vascular bed divided by the CARDIAC OUTPUT.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Metabolic Clearance Rate: Volume of biological fluid completely cleared of drug metabolites as measured in unit time. Elimination occurs as a result of metabolic processes in the kidney, liver, saliva, sweat, intestine, heart, brain, or other site.Hepatic Veins: Veins which drain the liver.Bilirubin: A bile pigment that is a degradation product of HEME.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Injections, Intravenous: Injections made into a vein for therapeutic or experimental purposes.Blood Pressure: PRESSURE of the BLOOD on the ARTERIES and other BLOOD VESSELS.Cross Circulation: The circulation in a portion of the body of one individual of blood supplied from another individual.Rats, Inbred F344Spleen: An encapsulated lymphatic organ through which venous blood filters.Organ Specificity: Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Bile Acids and Salts: Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.Mice, Knockout: Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Cholestasis: Impairment of bile flow due to obstruction in small bile ducts (INTRAHEPATIC CHOLESTASIS) or obstruction in large bile ducts (EXTRAHEPATIC CHOLESTASIS).Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Placenta: A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).Assisted Circulation: Pumping that aids the natural activity of the heart. (Dorland, 27th ed)Half-Life: The time it takes for a substance (drug, radioactive nuclide, or other) to lose half of its pharmacologic, physiologic, or radiologic activity.Living Donors: Non-cadaveric providers of organs for transplant to related or non-related recipients.Biotransformation: The chemical alteration of an exogenous substance by or in a biological system. The alteration may inactivate the compound or it may result in the production of an active metabolite of an inactive parent compound. The alterations may be divided into METABOLIC DETOXICATION, PHASE I and METABOLIC DETOXICATION, PHASE II.Lipid Metabolism: Physiological processes in biosynthesis (anabolism) and degradation (catabolism) of LIPIDS.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.