Abstract
Green odor emitted by green leaves is presumed to show refreshing actions on mammals, besides roles of communicating signals between plants. We have demonstrated that green odor attenuates elevation of plasma ACTH level induced by an immobilization stress. Here, we determine whether green odor attenuates elevation of plasma corticosterone (CORT) level and whether these effects are adrenal hormone-mediated, using bilateral adrenalectomized and CORT pellet replaced (ADX + CORT) rats. Male Wistar rats of 8 weeks old were used. In ADX + CORT experiment, rats were adrenalectomized bilaterally and implanted 100mg CORT/cholesterol pellet subcutaneously under pentobarbital anesthesia (50 mg/kg ip). The rats were allowed to recover for more than 10 days before experiment. The day of experiment, rats were exposed to immobilization for 120 min (10:00 to 12:00). Plasma ACTH and CORT responses to the immobilization stress with or without green odor (mixture of 0.03% cis-3-hexenol and 0.03% trans-3 hexenal) were measures at end of and 2 days after the stress. Green odor decreased plasma CORT levels at the end of and 2 days after the stress. In ADX + CORT rats, neither the immediate nor the long-lasting plasma ACTH response was affected by green odor exposure. These results suggest that green odor affects on plasma ACTH and CORT levels via feedback mechanisms of HPA axis. [Jpn J Physiol 55 Suppl:S207 (2005)]
