Tianeptine is an anti-depressant drug that also has an anti-ulcer activity. In this study, it was investigated whether or not alpha(2)-adrenoreceptors have a role in the anti-ulcer effect mechanism of tianeptine. Furthermore, we investigated both intact and adrenalectomized rats to determine whether or not the anti-ulcer activity of tianeptine is related to adrenal gland hormones involved in this mechanism. In all rats, 25 mg/kg indomethacin produced gastric ulceration. Tianeptine was administered to the indomethacin-induced ulcers in the rats at different doses. Yohimbine, selective alpha(2)-receptor blocker, was given (10 mg/kg) to some rats (adrenalectomized 6 groups and intact 4 groups), for blockage of the alpha 2-receptor. Tianeptine showed antiulcer effects of 59.6-81.6% in all animals. The results of this study show that tianeptine caused a significant anti-ulcer activity in both adrenalectomized and intact rats. Tianeptine does not have an anti-ulcer effect in rats which have been given yohimbine. Thus, the adrenal gland hormones do not have a direct effect on the anti-ulcer activity of tianeptine. This drug may be directly related to the alpha 2-adrenoreceptors. Moreover, the anti-ulcer effect shows an increase in parallel with increasing dose. This property of tianeptine could make it suitable for use in the treatment of both depression and peptic ulcer patients.