Changes in corticosterone levels in iron deficient rats

Abstract

The hypothesis that behavioural changes in iron deficiency are a product of stress was tested by monitoring corticosterone levels. Adult hooded rats were placed on an iron deficient diet for 2 (Stage 1), 8 (Stage 2) or 12 (Stage 3) weeks. When trained and tested on a single-trial taste aversion task, iron deficient animals showed the same performance as seen in previous experiments. Poor performance in early iron deficiency were followed by a temporary return to normal levels as the deficiency progressed, and falling below normal with continued iron depletion. Iron deficient animals failed to demonstrate the predicted stress-related changes in cortocosterone levels. Instead of an increasing in corticosterone levels after conditioning, levels fell to well below normal at all stages of deficiency following conditioning. Iron deficiency probably limits the action of certain enzymes responsible for corticosterone production. Due to the similarity of changes in catecholamines in stress and iron deficiency, it is possible that these changes will explain the pattern of behavioural response in iron depletion.