Nonsaturable amino acid reabsorption in kidneys of normal and mercury-poisoned rabbits

Journal Article · Tue Nov 01 00:00:00 EST 1988 · Proceedings of the Society for Experimental Biology and Medicine; (USA)

DOI:https://doi.org/10.3181/00379727-189-42802· OSTI ID:5030245

Foulkes, E C; Blanck, S ^[1]

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1. Univ. of Cincinnati, OH (USA)

At high plasma concentrations, a high-capacity, low-affinity or nonsaturable flux (J{sub hc}) accounts for a residual fractional reabsorption of cycloleucine, aspartate, and AIB of approximately 50% of the filtered load in rabbits; J{sub hc} in micromoles per milliliter glomerular filtrate is reduced in Hg-poisoned animals. The nonsaturable flux of cycloleucine is characterized by a transepithelial transit time (TET) of approximately 2 min in control animals; it was consistently much longer in Hg-poisoned animals. The clearance ratio of creatinine/inulin averaged 1.0, and no J{sub hc} could be demonstrated for glucose. We conclude that J{sub hc} is a high-capacity, low-affinity amino acid flux which passes through an intracellular solute pool, and which is sensitive to Hg at both the brush border and the basolateral cell membrane. If calculation of the saturation constants of aspartate reabsorption is restricted to experiments in which U/P <1.0, i.e. where J{sub hc} is unlikely too contribute greatly to reabsorption, values some 20% lower than those previously reported are obtained; the Hg inhibition still is apparently uncompetitive in nature.

• OSTI ID: 5030245
• Journal Information: Proceedings of the Society for Experimental Biology and Medicine; (USA), Vol. 189:2; ISSN 0037-9727
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
MEMBRANE TRANSPORT
KIDNEYS
SENSITIVITY
MERCURY
TOXICITY
RABBITS
ANIMALS
BODY
CARBOXYLIC ACIDS
ELEMENTS
MAMMALS
METALS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
VERTEBRATES
560300* - Chemicals Metabolism &amp; Toxicology