Effects of isosorbide-5-mononitrate and isosorbide-2-mononitrate on the contractile and electrical activity and on the content of cyclic nucleotides in isolated heart muscles of the guinea-pig and dog.
Isosorbide-5-mononitrate and isosorbide-2-mononitrate, the metabolites of isosorbide dinitrate, were studied for their effects on the contractile and electrical activity and on the content of cyclic nucleotides in isolated heart muscles of guinea-pig and dog. Isosorbide-5-mononitrate at all concentrations tested and isosorbide-2-mononitrate at low concentrations did not produce significant changes in the mechanical activity of guinea-pig heart preparations. Isosorbide-2-mononitrate in concentrations above 10(-4) M inhibited the contractility and shortened the action potential of guinea-pig and dog heart muscle. Neither mononitrate had an effect on cAMP concentration but both induced a significant elevation of cGMP content in guinea-pig heart tissue, the effect of isosorbide-2-mononitrate being greater.
Chemical Pharmaceutical Research Institute, Sofia, Bulgaria.
R
R
Atanassova
G
G
Spassov
R
R
Balansky
K
K
Boev
D000818:Animals; D000242:Cyclic AMP / Q000032:analysis*; D006152:Cyclic GMP / Q000032:analysis*; D004285:Dogs; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000502:physiology; D066298:In Vitro Techniques; D007548:Isosorbide Dinitrate / Q000031:analogs & derivatives* / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects*; D014665:Vasodilator Agents / Q000494:pharmacology*
D014665:Vasodilator Agents; C030398:isosorbide-2-mononitrate; D000242:Cyclic AMP; D006152:Cyclic GMP; D007548:Isosorbide Dinitrate; C030397:isosorbide-5-mononitrate