The influence of unilateral vertebral artery occlusion on bilateral inner ear blood flow in rats.

We investigated the influence of unilateral vertebral artery (VA) occlusion on bilateral inner ear blood flow in rats using laser Doppler flowmetry for the measurement of bilateral cochlear blood flow (CBF) and photochemically initiated thrombosis for VA occlusion. BP and CBF showed little change by unilateral VA occlusion alone. However, subsequent hypotension induced by venesection not only reduced CBF but also caused imbalance between bilateral CBF reduction rates. CBF changed independently of BP, indicating the existence of a local CBF regulatory system.