Effect of fibrinogen degradation products (FDP) on heart rate and some metabolic parameters in the rat.

Investigations were carried out in vitro and in vivo on the effects of FDP on the rat heart. It was found that FDP have a positive chronotropic and inotropic effect. In in vivo investigations it was shown that the peptides raise the activity of phosphorylase a in the heart and increase slightly blood FFA and lactate levels decreasing glycogen content in the myocardium. The effects of the examined peptides are blocked partly by propranolol and reserpine, while phentolamine failed to change the FDP action. These data suggest that FDP exert chronotropic and inotropic effects through their action on the beta-adrenergic receptors in the myocardium.