Journal of Applied Physiology, Vol 38, Issue 3 389-394, Copyright © 1975 by American Physiological Society
Rabbit's ear in cold acclimation studied on the change in ear temperature
E. Harada and T. Kanno
The role of the rabbit's ear in cold acclimation was studied by varying the
temperature of a climatic room in the range from -10 to +30 degrees C; The
skin temperature in a nonanesthetized rabbit's ear showed a characteristic
response to changes in ambient temperatures; plotting the ear temperature
against the ambient temperature yielded an S-shaped curve. The mean ambient
temperature corresponding to the inflection point on the S-shaped curve
shifted significantly from about 13 degrees C to about 8 degrees C after
cold acclimated of a group fed for 7 wk at -10 degrees C. The shift of the
S-shaped curve after cold acclimation may not be due to the change in the
norepinephrine sensitivity of the vascular beds of the ear: the effect of
norepinephrine on the pressure-flow curve in the isolated rabbit's ear was
almost unchanged between the control and the cold-acclimated groups. It is
proposed that the shift of the inflection point gives a qualitative index
of the acclimated state of the rabbit at a particular temperature.
