Abstract
The plasma levels of various hormones are known to change during motion sickness, and the degree of change is believed to be related to the susceptibility of a person to motion sickness.
In the present study, healthy adult volunteers were exposed to Coriolis acceleration using a rotary chair, and the changes in the plasma levels of various hormones were monitored. The severity of motion sickness symptoms was graded in accordance with Graybiel's diagnostic scoring method, and the subjects were classified into a high susceptibility group and a low susceptibility group. The changes in the hormone levels were then compared between the two groups.
After the onset of motion sickness, the plasma levels of ADH, ACTH, prolactin, cortisol and adrenalin increased significantly in the high susceptibility group, and the increase was most striking for ADH. In the low susceptibility group, on the other hand, there were almost no changes in the hormone levels.
Although the high susceptibility group showed a significant increase in the hormone levels during motion sickness, it was not clear whether said increases were simply due to a higher responsiveness of the endocrine system (centering on the hypothalamic-pituitary-adrenal system) or due to a higher responsiveness of the individual hormones to the stress of Coriolis acceleration in this group.
In consideration of the finding that the ADH level showed the most striking change and our knowledge of the action mechanism of ADH in the central nervous system, etc., ADH is speculated to play an important role in the development of motion sickness.
