[The effect of proxodolol on systemic and regional hemodynamics]

The effect of the new hybrid (beta-, alpha-) adrenoceptor blocking drug proxodolol on cardiac output and its distribution between 16 vascular regions, by using the microsphere method on anesthesized normotensive rats and rats with persistent renovascular hypertension. Proxodolol given in beta-adreno-blocking doses similar to those of labetalol was shown to exert vasodilating effects in normotensive rats. Renal, adrenal, splenic, and skeletal muscle vessels were most sensitive to labetalol, whereas cardiac and pulmonary vessels were responsive to proxodolol. In rats with persistent renovascular hypertension, proxodolol had a vasodilating effect only when it was used in doses inducing alpha-adrenoceptor blockade.