Effects of heparin on the electrophysiological and mechanical properties of early embryonic chick hearts.
The effect of heparin (1-200 microg/ml) on several functional properties of 4-day-old embryonic hearts was studied. Intracellular recordings either from cells of the atrium, the atrio-ventricular canal or the ventricle were made on the isolated and perfused hearts. In all impaled myocardial cells, heparin produced an increment in the maximal rate of rise and amplitude of the action potentials and the duration was slightly diminished. In addition, heparin provoked a reduction in the spontaneous beating frequency, while the electrical excitability and the conduction velocity of the atrium and the ventricle were increased. The measurements of atrio-ventricular latency revealed that it was diminished, i.e. the propagation of impulses through the atrio-ventricular canal was improved. Simultaneously with these changes, heparin incremented the amplitude of contraction of either the atrium or the ventricle importantly.
Alanís
J
J
Unidad Experimental de Electrofisiologia "Arturo Rosenblueth", Apartado Postal No. 15, Jiutepec, Morelos, Mexico, Código Postal 62550.
Argüello
C
C
Polo
L
L
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002642:Chick Embryo; D004553:Electric Conductivity; D004594:Electrophysiology; D006321:Heart / Q000187:drug effects / Q000196:embryology* / Q000502:physiology*; D006339:Heart Rate / Q000187:drug effects; D006493:Heparin / Q000494:pharmacology*; D008564:Membrane Potentials / Q000187:drug effects; D009200:Myocardial Contraction / Q000187:drug effects
D006493:Heparin; D002118:Calcium