Abstract
To investigate the change of corticosteroidogenesis under an environmental stress, rats were exposed to mechanical vibration (vertically, 2G with 10 cycle/sec.) for 5 hours. The results obtained are as follow.
1. The level of corticosterone in adrenal and serum increased significantly (by analysis of variance, P<0.01) about 3 times compared with control.
2. The level of adrenal NADPH and NADH increased significantly (by analysis of variance, P<0.05) but only about 1.3 times compared with control. There was not a change of NADP or NAD level in adrenal.
3. Swelling of adrenal mitochondria from stressed rat, which was estimated as a change with Ca++ at 520 mμ absorbance, resulted in a marked decrease (by Welch's test, P<0.01). It was suggested that there was some change of mitochondria membrane in adrenal.
The findings mentioned above were observed soon after the beginning of vibration and continuously during vibration.
As a result, it is considered that NADPH, coenzyme for steroid hydroxyration, is increased a little but the turnover rate of NADP system may be enhanced by a change of mitochondrial membrane.
