2009 Volume 49 Issue 7 Pages 783-790
Aim: As the pathogenesis of functional dyspepsia (FD) considering brain-gut axis, it is thought that daily stressors affect the autonomic nervous system (ANS), gastrointestinal motility, and various chemical mediators thereafter causing abdominal symptoms. We examined the effects of external stresses on gastric emptying in rats and the association of ANS with FD patients. Methods: 1. We examined various parameters: body weight, relative organ weight, catecholamine levels, and gastric emptying in 8-weeks old rats after water immersion stress restraint for 5 days. 2. We analyzed the 24hrs heart rate variability for FD patients after obtaining the questionnaire of daily stressors: component of high frequency (HF: 0.15-0.40Hz) for parasympathetic function and ratio of component of low frequency (LF: 0.04-0.15Hz) to HF component for sympathetic function. We examined 1) 24hrs balance, 2) changes after meal and cold or mental mathematical stressors, 3) effects of tofisopam, a psychovegetative regulator. Results: Stress significantly decreased body weight and relative weight of thymus, and increased relative weight of adrenal glands. Stress increased serum ACTH, corticosterone, adrenalin, and noradrenalin levels. Gastric emptying was decreased in the early phase of the stress restraint and increased in the late phase. Plasma total and inactive ghrelin levels were increased at 24hrs stress restraint and thereafter gradually decreased. Active ghrelin level began to increase at that time. Basal levels of parasympathetic tone were lower and the levels of sympathetic tone were higher in FD patients compared to those of controls. Parasympathetic tone levels of all controls during 30min after meal were higher than their basal condition. But those levels were increased in about half of FD patients. Sympathetic tone levels from 90 to 120 minutes after meal were increased in almost controls but in half of FD patients. Treatment with tofisopam ameliorated the basal imbalance to the normal balanced levels of ANS followed by improving dyspeptic symptoms of FD patients. Conclusions: Fragility of ANS and external stress may be associated with the gastric emptying and abdominal symptoms in FD patients. Treatment with tofisopam, a psychovegetative regulator, may be effective for FD patients.
