Cochlear Blood Flow and Function: Effect of Pressor Agents

Normal values for blood flow velocity in some terminal vascular units of the cochlea (stria vascularis and spiral ligament) and for carotid blood pressure are presented along with the percentage changes produced by administration of epinephrine, norepinephrine, vasopressin and serotonin. Increases in flow velocity in these cochlear vessels can be produced. These are closely related to the measured increases in mean carotid blood pressure. Cochlear function as measured by the microphonic response to a moderate acoustic stimulus is not altered by this increase in cochlear blood flow. Some general relations between flow velocity, oxygen utilization and cell function are discussed.