Effects of VA-045 on peripheral and central circulation in anesthetized dogs.

1. The effects of VA-045, a novel apovincaminic acid derivative, vinpocetine, apovincaminic acid, brovincamine and nicergoline on peripheral and cerebral circulation were examined in anesthetized dogs. 2. Peripheral circulation: VA-045 induced a transient decrease in both blood pressure (BP) and heart rate (HR) andd an increase in vertebral arterial blood flow (VBF) without affecting femoral arterial blood flow (FBF) or carotid arterial blood flow (CBF). Vinpocetine had no effect on BP, HR, VBF, FBF or CBF. Apovincaminic acid decreased HR and increased VBF without affecting FBF, CBF or BP. Brovincamine increased VBF and decreased CBF without affecting BP or FBF. Nicergoline decrease BP without affecting VBF, FBA or CBF. 3. Cerebral circulation: VA-045 increased cerebral blood flow (CerBF) without affecting BP. Brovincamine also increased CerBF and decreased BP. The potency of VA-045 in increasing CerBF was stronger than that of brovincamine. Vinpocetine and apovincaminic acid had no effect on BP or CerBF. Nicergoline decreased BP but did not affect CerBF. 4. These findings indicate that VA-045 has a more selective vasodilative effect on the vertebral and cerebral arteries than the other reference drugs.