Effect of a-blocker on Peripheral Circulation of Rabbit\u27s Ear in Local Cold an Various Surrounding Temperatures

Cold induced vasooscillation is caused by Norepinephrine (NE) released from sympathetic nerve endings. It is here well knoun that Phenoxybenzamine (PhB) ，a-blocker，blocks the constriction effect of NE In this experiment，the change of PhB effect on cold induced vasooscillation and on the level of central ear arterial temperature (T-CEA) was investigated under three different temperature conditions by using intact，unanesthetized rabbit ears. Tog et the direct drug effect，P hB was injected locally into the earlobe. Thermistor and laser-Doppler flow meters were used as noninvasive methods