[Inner ear blood flow with betahistine--an animal experiment study]

The influence of the drug Betahistin on the cochlear blood flow (CBF) was checked on 15 guinea pigs (6 controls) (Charles River, BFA 350-450 g) by means of the hydrogen clearance method. The hydrogen clearance measurements were carried out under alpha-chloralose-ethylurethane anaesthesia, artificial respiration with simultaneous control of the electrocardiogram, arterial blood pressure and body temperature. The actual arterial pH-value was checked hourly. Indirect measurement of CBF was carried out in the perilymphatic space (basal turn) before and after intravenous application of Betahistin (vena jugularis externa) (dosage: 0.11 mg/kg/min). The mean arterial blood pressure remained within the 10% range during the experiments. Under Betahistin-treatment the CBF showed an significant increase (p = 0.05). Despite this favourable pharmacological efficiency of Betahistin it must be pointed out that the general application of vasoactive drugs, especially of vasodilative drugs, in the treatment of postulated inner ear blood flow disturbances is presently controversial.