Impaired gastric slow waves induced by spatial disorientation and effect of domperidone.
OBJECTIVE
Our aims were to investigate the dominant frequency and regularity of gastric myoelectrical activity during motion sickness induced with the advanced spatial disorientation demonstrator (ASDD) and to evaluate the effect of domperidone on gastric myoelectrical activity and gastrointestinal symptoms during motion sickness.


METHODS
Thirteen healthy volunteers participated in this study. This study was executed using the ASDD, which could duplicate several spatial disorientation phenomena in a safe, controlled environment. Each subject participated in two sessions and received oral administration of 10 mg domperidone before the study in one of the sessions. In each session, three 15-min EGG recordings were made before, during, and after rotation. The symptoms were scored by Graybiel's scale of motion sickness before and after rotation. All EGG data were subjected to computerized spectral analysis to obtain the percentage of normal 2-4 cycles/min (cpm) slow waves, percentage of tachygastria, EGG dominant frequency and power, and instability coefficient of the dominant frequency.


RESULTS
We have found that the percentage of normal gastric slow wave was decreased (control session: 86.2 +/- 4.0% vs 70.0 +/- 5.4%, p < 0.01; domperidone session: 82.7 +/- 4.6% vs 69.8 +/- 5.6%, p < 0.03) and the percentage of tachygastria was increased (control session: 8.7 +/- 3.2% vs 17.8 +/- 5.6%, p < 0.01; domperidone session: 9.2 +/- 3.3% vs 18.1 +/- 3.5%, p < 0.01) after rotation in both sessions. The minute-by-minute variation of the gastric slow wave frequency was significantly increased during rotation in both sessions (control: 0.74 +/- 0.16 vs 1.35 +/- 0.19, p < 0.01; domperidone: 0.90 +/- 0.20 vs 1.47 +/- 0.17, p < 0.01). Domperidone did not prevent dysrhythmia or the symptoms of motion sickness.


CONCLUSIONS
The percentage of normal gastric slow waves is decreased and the percentage of tachygastria is increased with spatial disorientation. Domperidone does not prevent gastric dysrhythmia or the symptoms of motion sickness induced with spatial disorientation.
Kono
T
T
The Department of Physiology, 2nd National Defense Medical College, Tokorozawa, Japan.
Tokumaru
O
O
Mizumoto
C
C
Tatsuno
J
J
Chen
J D
JD
D000328:Adult; D000932:Antiemetics / Q000494:pharmacology*; D004294:Domperidone / Q000494:pharmacology*; D018492:Dopamine Antagonists / Q000494:pharmacology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009041:Motion Sickness / Q000503:physiopathology*; D016065:Myoelectric Complex, Migrating / Q000187:drug effects*; D009949:Orientation; D013028:Space Perception; D013270:Stomach / Q000187:drug effects / Q000503:physiopathology*
D000932:Antiemetics; D018492:Dopamine Antagonists; D004294:Domperidone