Increased Adrenocortical Activity in the Neonatal Rat Following Handling

Abstract

A standard handling procedure, employed with 2-day-old rats, caused a significant rise in plasma corticosterone 1/2 hr after the pups were returned to the maternity cage and the mother. This procedure consists of removing the pups from the maternity cage, placing them individually into 1-gallon cans partially filled with shavings, leaving them undisturbed in the cans for 3 min and then returning the pups to the maternity cage. Two other procedures, variants on the handling technique, also evoked a significant adrenocortical response: The first was to leave the pups alone in handling cans for 33 min; the second was to place the pups into an empty maternity case for 1/2 hr after the usual 3 min in handling cans. The final experiment showed that the corticosterone response could be prevented if the pups were placed in handling cans maintained at 35.5 C. (Endocrinology81: 1047, 1967)