Effect of vitamin C upon the acute stress response

This laboratory previously reported that 200 mg vitamin C/day supplementation to Sprague-Dawley rats significantly reduced the adrenal cortex response to chronic immobilization stress. This study extends that research to investigate the effect of the same three-week feeding of vitamin C by oral gavage upon the acute stress response to intraperitoneal injection of cold, hypertonic saline. Stress had statistically significant (p < 0.05) effects on adrenal ascorbic acid (AAA) depletion, hypothalamic CRH and blood levels of ACTH and corticosterone. Vitamin C treatment had a modulating effect upon these parameters, though not statistically significant. The composite pattern of increased hypothalamic CRH, reduced depletion of AAA and lowered stress levels of blood ACTH and corticosterone under vitamin C feeding is consistent with a negative modulation of the acute stress response. In vitro incubation of adrenal glands from vitamin C-treated animals suggests that vitamin C may slightly reduce the responsivity of the gland to ACTH.