ETHANOL AUGMENTS THE BAROREFLEX-INHIBITORY EFFECTS OF SCIATIC-NERVE STIMULATION IN THE ANESTHETIZED DOG

Electrical stimulation of somatic afferent fibres in the sciatic nerve has been used as a model of injury in the anaesthetized dog. Stimulat ion of the sciatic nerve (during reflexly induced periods of apnoea to obviate any respiratory effects of sciatic stimulation) led to a simu ltaneous increase in arterial blood pressure and heart rate and a decr ease in baroreflex sensitivity. Infusion of ethanol sufficient to prod uce clinically relevant plasma ethanol levels (100-200 mg%) had no con sistent effects on baroreflex sensitivity, but enhanced the presser re sponse and significantly augmented the inhibitory effects of sciatic s timulation on the baroreflex. Since ethanol is commonly associated wit h injury in man, such changes in the response to 'injury' may modify t he patients' cardiovascular response to the injury and complicate diag nosis.