[Effects of oxyfedrine on high blood viscosity and myocardial necrosis induced by epinephrine and ice water stress in rats]

Acute high blood viscosity (HBV) and myocardial necrosis was established by epinephrine (Epi) and ice water stress in rats. Effects of iv oxyfedrine (Oxy) on HBV, plasma viscosity (PV), hematocrit, erythrocyte electrophoretic time (EET), and fibrinogenic viscosity (FV) were studied in model. Results showed that Oxy 1 mg.kg-1 iv markedly decreased the arterial and venous blood HBV at shear rates of 700 s-1 and 70 s-1, respectively (P < 0.01). There were significant differences in the alleviation of HBV among 3 groups (Oxy 0.01, 0.1, and 1 mg.kg-1 iv). The above doses markedly decreased the HBV, PV, and FV, and shortened the EET. Effects of iv Oxy on the myocardial necrosis rat model were scrutinized under the light and electron microscopes. Oxy iv 1 mg.kg-1.d-1 x 1, 3, and 5 d prevented or mitigated the occurrence and development of myocardial necrosis. The structure of heart mitochondria and myofibrils were clearly discernible. This action may be related to the alleviation of HBV by Oxy.