The effect of propranolol on blood viscosity changes induced by experimental coronary occlusion.

The effect of propranolol treatment was investigated in the myocardial ischemia-induced hyperviscosity state in anesthetized dogs. In untreated control dogs, low shear blood viscosity rose progressively, following an acute occlusion of the left anterior descending coronary artery; this effect was partially but significantly reduced by intravenously administered propranolol (0.2 mg/kg). The effect of the in vitro addition of propranolol was also determined upon viscosity of blood samples obtained at hourly intervals from dogs subjected to similar coronary ligation. The in vitro addition of propranolol did not produce a similar reversal of the hyperviscosity state observed in the blood obtained from dogs after coronary ligation.