Na-dependent L-proline transport by eel intestinal brush-border membrane vesicles

Journal Article · Sat Oct 01 00:00:00 EDT 1988 · American Journal of Physiology; (USA)

OSTI ID:6289791

Vilella, S; Ahearn, G A; Cassano, G; Storelli, C ^[1]

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1. Universita' di Lecce (Italy) University of Hawaii at Manoa, Honolulu (USA)

L-({sup 3}H)proline uptake by brush-border membrane vesicles prepared from intestinal mucosa of the European eel, Anguilla anguilla, was stimulated by a transmembrane Na gradient (out > in.) Kinetic analysis of L-proline influx, under short-circuited membrane potential conditions, indicated the presence of an apparent single Na-dependent carrier process and a nonsaturable transfer component with an apparent diffusional permeability (P) of 1.53 {plus minus} 0.35 {mu}l{center dot}mg protein{sup {minus}1}{center dot}min{sup {minus}1}. An imposed transmembrane potential (inside negative) increased apparent L-proline binding affinity (lowered K{sub app}) without appreciably altering maximal amino acid influx (J{sub max}). Hill analysis of L-proline influx over a wide range of external Na concentrations indicated a 1:1 stoichiometry for Na-proline cotransport. Use of amino acid inhibitors of L-proline influx suggested that L-proline transfer may occur by either a classical Na-dependent A System with a wide substrate specificity or by the combination of Na-dependent PHE (phenylalanine preferring) and IMINO (proline, {alpha}-methylaminoisobutyric acid preferring) Systems.

• OSTI ID: 6289791
• Journal Information: American Journal of Physiology; (USA), Vol. 255:4; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
MEMBRANE TRANSPORT
BIOCHEMICAL REACTION KINETICS
PROLINE
INTESTINAL ABSORPTION
TRITIUM COMPOUNDS
AMINO ACIDS
EEL
INTESTINES
SODIUM COMPOUNDS
ABSORPTION
ALKALI METAL COMPOUNDS
AMINES
ANIMALS
AQUATIC ORGANISMS
AZOLES
BODY
CARBOXYLIC ACIDS
DIGESTIVE SYSTEM
FISHES
GASTROINTESTINAL TRACT
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
KINETICS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PYRROLES
PYRROLIDINES
REACTION KINETICS
UPTAKE
VERTEBRATES
551001* - Physiological Systems- Tracer Techniques