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Transport of procainamide via H(+)/tertiary amine antiport system in rabbit intestinal brush-border membrane.
- Source :
-
American journal of physiology. Gastrointestinal and liver physiology [Am J Physiol Gastrointest Liver Physiol] 2000 Oct; Vol. 279 (4), pp. G799-805. - Publication Year :
- 2000
-
Abstract
- Transport characteristics of procainamide in the brush-border membrane isolated from rabbit small intestine were studied by a rapid-filtration technique. Procainamide uptake by brush-border membrane vesicles was stimulated by an outward H(+) gradient (pH(in) = 6.0, pH(out) = 7.5) against a concentration gradient (overshoot phenomenon), and this stimulation was reduced when the H(+) gradient was subjected to rapid dissipation by the presence of a protonophore, FCCP. An outward H(+) gradient-dependent procainamide uptake was not caused by H(+) diffusion potential. The initial uptake of procainamide was inhibited by other tertiary amines with N-dimethyl or N-diethyl moieties in their structures, such as triethylamine, dimethylaminoethyl chloride, and diphenhydramine, but not by tetraethylammonium and thiamine. Furthermore, procainamide uptake was stimulated by preloading the vesicles with these tertiary amines (trans-stimulation effect), indicating the existence of a specific transport system for tertiary amines. These findings indicate that procainamide transport in the intestinal brush-border membrane is mediated by the H(+)/tertiary amine antiport system that recognizes N-dimethyl or N-diethyl moieties in the structures of tertiary amines.
- Subjects :
- Amines pharmacology
Animals
Biological Transport drug effects
Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone pharmacology
Cimetidine pharmacology
Ethylamines pharmacology
Guanidine pharmacology
Hydrogen-Ion Concentration
Intestine, Small
Kinetics
Male
Mannitol pharmacokinetics
Microvilli drug effects
Potassium metabolism
Rabbits
Sodium metabolism
Amines metabolism
Intestinal Mucosa physiology
Microvilli physiology
Procainamide pharmacokinetics
Subjects
Details
- Language :
- English
- ISSN :
- 0193-1857
- Volume :
- 279
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- American journal of physiology. Gastrointestinal and liver physiology
- Publication Type :
- Academic Journal
- Accession number :
- 11005768
- Full Text :
- https://doi.org/10.1152/ajpgi.2000.279.4.G799