6533b7dcfe1ef96bd1271754

RESEARCH PRODUCT

Tetrodotoxin slightly shortens action potential duration in ventricular but not in atrial heart muscle.

H. NawrathH. Jakob

subject

medicine.medical_specialtyHeart VentriclesGuinea PigsAction PotentialsTetrodotoxinBiologySodium currentGuinea pigCellular and Molecular Neurosciencechemistry.chemical_compoundInternal medicinemedicineRepolarizationAnimalsHumansVentricular FunctionHeart AtriaAtrium (heart)Molecular BiologyPharmacologymusculoskeletal neural and ocular physiologySodiumHeartCell BiologyAtrial FunctionElectrophysiologymedicine.anatomical_structurechemistryVentriclecardiovascular systemTetrodotoxinCardiologyMolecular MedicineAction potential durationCalciumcirculatory and respiratory physiology

description

Tetrodotoxin (TTX), at concentrations significantly decreasing maximal upstroke velocity (dV/dtmax) of the action potential, exerted variable effects on action potential duration (APD) in different myocardial preparations. APD was virtually unchanged by tetrodotoxin in the guinea pig atrium, but slightly shortened in the guinea pig ventricle at maximally effective concentrations. In the human ventricle, both dV/dtmax and APD were reduced in the same concentration range of TTX. These results suggest that a TTX-sensitive sodium current significantly contributes to the repolarization phase of the action potential in ventricular but not in atrial heart muscle.

yearjournalcountryeditionlanguage
1988-01-15Experientia
10.1007/bf01960226https://pubmed.ncbi.nlm.nih.gov/3350111