[Effects of tofisopam on the physiological changes induced by stress loading and hypothalamic stimulation (author's...

Effects of tofisopam on the gastric ulceration induced by immobilization stress in olfactory-bulbectomized rats, propulsion of the small intestine caused by water immersion-stress in rats and autonomic responses to electrical stimulation of the hypothalamus in rabbits were investigated. Immobilization stress loading of 16.5 hours each for 10 days caused the augmentation of incidence and average index of gastric ulceration in olfactory-bulbectomized rats, compared with non-treated rats. Tofisopam 100 mg/kg, p.o. significantly inhibited the gastric ulceration in olfactory-bulbectomized rats. Water immersion-stress loading for 2 hours caused a significant increase in propulsion of the small intestine in rats. This increase was reversed to control levels after the oral administration of tofisopam in a dose of 100 mg/kg. Tofisopam at dose of 1 mg/kg i.v. inhibited the contraction of ear microvessels, the decrease in earlobe temperature and the mydriasis induced by electrical stimulation of the medial hypothalamic area in rabbits, Moreover, these inhibitions were also shown by the intra-cerebrospinal injection of tofisopam at a dose of 0.1 mg/kg. From these results, it is concluded that tofisopam could restore the autonomic abnormality induced by stress-loading and exerts such effects by acting on the hypothalamus, an area of the brain, which regulates autonomic nervous functions.