Effect of enalapril on intracellular resistance and conduction velocity in rat ventricular muscle.
The effect of enalapril on the intracellular resistance (ri) and conduction velocity was investigated in isolated rat trabeculae. The results indicated a decline in the internal resistance of 35.5% (SE +/- 3.3) and an increase in conduction velocity of 58.7% (SE +/- 6.6). The action potential duration was not altered, but the resting potential was increased by 10.5 mV (SE +/- 4.4). Enalaprilat had no effect on ri probably because the molecule is a diacid and does not cross the cell membrane. These findings indicate that the renin-angiotensin system is involved in the modulation of cell communication in cardiac muscle and that the beneficial effect of the drug in patients with congestive heart failure is, in part, related to an improvement of electrical synchronization of heart cells.
De Mello
W C
WC
Department of Pharmacology, School of Medicine Medical Sciences Campus, San Juan, Puerto Rico 00936-5067.
Crespo
M J
MJ
Altieri
P
P
D000200:Action Potentials / Q000187:drug effects; D000669:Amplifiers, Electronic; D000818:Animals; D004594:Electrophysiology; D004656:Enalapril / Q000494:pharmacology*; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D006329:Heart Conduction System / Q000187:drug effects*; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D066298:In Vitro Techniques; D008839:Microelectrodes; D009206:Myocardium / Q000166:cytology / Q000378:metabolism; D011189:Potassium Chloride; D051381:Rats
D011189:Potassium Chloride; D004656:Enalapril