Cimetidine transport in rabbit renal cortical brush-border membrane vesicles

Journal Article · Sun Mar 01 04:00:00 EST 1987 · Am. J. Physiol.; (United States)

OSTI ID:5970440

McKinney, T D; Kunnemann, M E

Cimetidine is an organic cation and commonly prescribed drug that is eliminated primarily by proximal renal tubular secretion. The present studies evaluated cimetidine transport in rabbit renal cortical brush-border membrane vesicles (BBMV). (/sup 3/H)Cimetidine uptake varied inversely with media osmolarity and was stimulated with uphill transport above equilibrium values (overshoot) produced by an initial proton gradient directed from the vesicle interior outwardly. Uphill transport occurred earlier and was of greater magnitude at 25/sup 0/C than at 5/sup 0/C. pH-stimulated (/sup 3/H)cimetidine uptake was inhibited by excess nonradiolabeled cimetidine, quinidine, and procainamide but was affected little by probenecid. Tetraethylammonium inhibited cimetidine uptake in the presence and absence of an initial proton gradient, indicating that nonionic diffusion and simple diffusion cannot totally account for cimetidine transport in BBMV. Preloading BBMV with an excess of procainamide enhanced cimetidine uptake. These results are consistent with the hypothesis that cimetidine is transported across BBMV by organic cation-proton exchange.

• Research Organization: Univ. of Texas Health Science Center, San Antonio
• OSTI ID: 5970440
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:3; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BODY
CATIONS
CHARGED PARTICLES
DOSE-RESPONSE RELATIONSHIPS
IONS
KIDNEYS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE TRANSPORT
ORGANIC COMPOUNDS
ORGANS
PH VALUE
PHYSIOLOGY
RABBITS
TRITIUM COMPOUNDS
VERTEBRATES