Perfusion of the isolated rat heart at constant heart rate and coronary flow with the inhibitor of cyclic nucleotide phosphodiesterase, pentoxifylline (10-4 moles/l), produced no significant effect on the maximum rate and the peak of contraction, but increased the maximum rate of relaxation. cAMP level and cAMP-dependent protein kinase activity were increased in the absence of changes in cGMP. The results were identical in hearts of reserpinized rats.
ASJC Scopus subject areas
- Biochemistry, Genetics and Molecular Biology(all)