In an effort to determine the mechanism causing motion sickness, various studies have been conducted on the autonomic and central nervous systems. Recently, it was reported that the level of antidiuretic hormone (ADH) rises when motion sickness appears, and the possible involvement of hormones in the manifestation of motion sickness has become a focus of attention.
We induced motion sickness by Colioris stimulation in healthy adult volunteers, and examined hypothalamus-pituitary-adrenal hormones and neuropeptides before and after stimulation and during the recovery process.
In the high susceptibility group blood levels of ADH, ACTH, prolactin, cortisol, β-endorphin and MET-enkephalin and urinary levels of ADH immediately after stimulation were significantly higher than those in the low susceptibility group. These levels returned to normal after 30 minutes of rest. In the high susceptibility group the motion sickness score immediately after stimulation showed a significant correlations with the blood levels of ADH, ACTH and β-endorphin.
These results indicate that ADH, ACTH, β-endorphin and MET-enkephalin are involved in the nausea and vomiting of motion sickness. Moreover, it seems that the mechanism and effects of these hormones may differ from each other. Since the urinary level of ADH is very closely correlated with its blood level, the use of urinary ADH testing is advocated as a simple method with no discomfort.
