Anti-Vertigo Agents and Experimental Measurement of Inner Ear Temperature (Thermister Method)

Abstract

The influence of an anti-vertigo agent upon inner ear temperature was studied using an experimental inner ear temperature measuring method that utilizes a thermister. An injection needle-type thermister was inserted into inner ear of 34 normal rabbits through fossa fenestra rotunda by an inner ear fenestration operation (Honjo, 1954), and inner ear temperature was measured. Various anti-vertigo agents were administered and the time change of temperature was observed. At the same time the temperature of rectum was also measured by the same method as a control. Some anti-vertigo agents caused increases in inner ear temperature (7 % sodium bicarbonate, diphenidol, etc.), while others acted to reduce the temperature (pilocarpine, furosemide, etc.). Some showed only temporary action while others showed a sustained effect. The change of rectal temperature measured simultaneously roughly parallelled the fluctuation of inner ear temperature but the slope of the change of temperature was less sharp than that of the inner ear. To classify drugs according to the change of inner ear temperature may be a useful clue to judging the pharmacological action of anti-vertigo agents.