Low-molecular weight dialysable peptides, obtained by plasmin degradation of purified bovine fibrinogen preparations, have been shown to increase the chronotropic activity of isolated rat atria. This effect was dose dependent and was inhibited by inhibitors of glycolysis (NaF and 2-deoxy-D-glucose), but not by an inhibitor of oxidative phosphorylation (2,4-dinitrophenol). Propranolol, a β-blocking agent, was also ineffective. Fibrinogen-derived peptides increased both cAMP levels and phosphorylase α activity in stimulated atria. The increase of these parameters was transitory and appeared to precede the occurrence of the positive chronotropic effect. In the test situation used, the biochemical and functional modifications induced by fibrinogen-derived peptides were similar to those induced by glucagon.
- Cyclic AMP
- Fibrinogen degradation products
- Isolated rat atria
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience