Diastolic tension and contraction amplitude in calcium-loaded rat ventricular myocardium are differently affected by drugs

  • Herzig S
  • Mohr K
  • Schmidt S
 et al. 
  • 3

    Readers

    Mendeley users who have this article in their library.
  • 0

    Citations

    Citations of this article.

Abstract

1. 1. To obtain a measure of drug effects on myocardial function during diastole, the following experimental protocol was designed: rapid electrical stimulation (5 Hz) at high Ca2+ocaused an elevated diastolic tension, which could be subjected to drug-induced alterations. 2. 2. Antiarrhythmic drugs (quinidine, propafenone, procainamide, mexiletine) were able to lower diastolic force without appreciably decreasing contraction amplitude. Calcium antagonists (nifedipine, verapamil) lowered both parameters in parallel. 3. 3. Veratridine and Bay K 8644 both enhanced diastolic tension, but only Bay K 8644 concomitantly elevated contraction amplitude. 4. 4. These findings may be explained when taking into account differential actions of sodium- and calcium channel modulating drugs, respectively, on cellular Ca2+movements. In quantitative terms, the non-linear dependence of myocardial force on Ca2+ialso had to be considered. © 1991.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free