SOMATIC AFFERENT REGULATION OF PLASMA-CORTICOSTERONE IN ANESTHETIZED RATS

Effects of cutaneous stimulation on plasma corticosterone were examined in adult male Wistar rats anesthetized with pentobarbital. Under the resting condition, plasma corticosterone measured every 15 min between 1430 and 1630 h revealed no significant circadian fluctuations. Nociceptive mechanical stimulation of bilateral hindpaws by pinching for 10 min significantly increased plasma corticosterone for the following 1 h, whereas innocuous mechanical stimulation of bilateral hindlimbs by brushing for 10 min produced no significant change in plasma corticosterone. These results indicate that somatic sensory information from skin can influence secretion of corticosterone from the adrenal cortex after emotional factors are eliminated by anesthetizing the subjects.