Plasma corticosterone and restraint induced gastric pathology: age-related differences after administration of corticotropin releasing factor.

Corticotropin releasing factor (CRF) or saline was administered i.p. to rats aged either 100 or 220 days, followed by either brief handling or water immersion restraint. Plasma corticosterone was measured 75 min. later. Age of the animals in itself was not a significant factor either for basal levels of plasma corticosterone or for extent of restraint induced gastric pathology. However after CRF administration, young but not older animals revealed a significant increase in plasma corticosterone levels, and post restraint gastric ulcerations were more severe in older than young animals. CRF significantly decreased the number of restraint induced ulcers in young rats, while the cumulative ulcer length was increased in older animals.