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Title: Aquatic models for the study of renal transport function and pollutant toxicity

Studies of renal cell transport mechanisms and their impairment by xenobiotics are often limited by technical difficulties related to renal tubule complexity. Problems include the juxtaposition of multiple tubule segments with different transport functions and severely limited access to the tubular lumen. Some limitations can be overcome by the careful selection of an appropriate aquatic experimental system. Two aquatic models for the vertebrate proximal segment are discussed here. The first is the kidney from certain marine flounder, which offers the following advantages: long-term viability, little tissue of nonproximal origin, and easy tubule isolation. Data are presented to demonstrate how studies with flounder kidney can be used to elucidate cellular mechanisms whereby different classes of toxic pollutants may interact. Results from these experiments indicate that the excretion of certain anionic xenobiotics can be delayed (1) by other anionic xenobiotics that compete for secretory transport sites and (2) by compounds that disrupt cellular ion gradients and energy metabolism needed to drive transport. The second system is the crustacean urinary bladder, a simple, flatsheet epithelium. Bladder morphology and transport physiology closely resemble those of vertebrate proximal segment. Electron micrographs show a brush border membrane at the luminal surface, numerous mitochondria, and an infoldedmore » serosal membrane, while in vivo and in vitro transport studies show reabsorption of NaCl, nutrients and water and secretion of organic cations; organic anions are secreted in bladders from some species and reabsorbed in others. Moreover, since bladders can be mounted as flat sheets in flux chambers, studies with this tissue avoid the problems of complex renal tubule geometry and tissue heterogeneity and tissue heterogeneity that limit transport studies in proximal tubule.« less
Authors:
Publication Date:
OSTI Identifier:
6516394
Resource Type:
Journal Article
Resource Relation:
Journal Name: Environ. Health Perspect.; (United States); Journal Volume: 71
Research Org:
National Institute of Environmental Health Sciences, Research Triangle Park, NC
Country of Publication:
United States
Language:
English
Subject:
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.; MEMBRANE TRANSPORT; BIOLOGICAL MODELS; XENOBIOTICS; BIOLOGICAL EFFECTS; ATP-ASE; BENZOPYRENE; BLADDER; CRUSTACEANS; FISHES; KIDNEYS; MERCURY CHLORIDES; TRANSMISSION ELECTRON MICROSCOPY; WATER POLLUTION; ACID ANHYDRASES; ANIMALS; AQUATIC ORGANISMS; AROMATICS; ARTHROPODS; BODY; CHLORIDES; CHLORINE COMPOUNDS; CONDENSED AROMATICS; ELECTRON MICROSCOPY; ENZYMES; HALIDES; HALOGEN COMPOUNDS; HYDROCARBONS; HYDROLASES; INVERTEBRATES; MERCURY COMPOUNDS; MERCURY HALIDES; MICROSCOPY; ORGANIC COMPOUNDS; ORGANS; PHOSPHOHYDROLASES; POLLUTION; URINARY TRACT; VERTEBRATES 560300* -- Chemicals Metabolism & Toxicology