Adrenal Ascorbic Acid Response to Noise

　In an attempt to observe the response of the hypothalamo-hypophseal-adrenal system to noise, a series of experiments were carried out on rats. As an index of ACTH release from the anterior pituitary gland into the blood, the AAA concentrations following exposure to noise were determined. A decrease of AAA concentrations was found following a single exposure to noise. For rats exposed to noise for 10 days, 20 days and 30 days and sacrificed 30 minutes after the final exposure to noise no significant change in AAA concentrations was found. For rats exposed for 30 days and sacrificed l2 hours after the final noise exposure a significant increase in AAA concentrations was found. Because this significant increase was unexpected and no satisfactory reason for it could be found further studies and experiments have been undertaken and will be reported subsequently.