Relationship of Temperature to Sensitivity of the Mammalian Auricle to Sympathomimetic Amines

¹ From the Department of Pharmacology, Cornell University Medical College, New York City

The effects of temperature changes on the response of isolated cat and guinea pig auricles to sympathomimetic amines were studied. At 37°C, the cat auricle is about 1/10 as sensitive to Isuprel and epinephrine in terms of amplitude of contraction and from 1/10 to 1/100 as sensitive in terms of spontaneous rate as at 29°C. In isolated guinea pig auricles, norepinephrine was less effective at 37° than at 29°C, but quantitative relationships could not be determined because of rapid failure of this preparation at 37°C. In evaluating the significance of physiological studies performed at temperatures below 37°C, the possibility of altered sensitivity to drugs and hormones must be considered.

Note:
with the technical assistance of Ann Kirk.