[Effect of dexamethasone on indomethacin-induced gastric erosion formation upon duration of the hormonal action].

The aim of the study was to verify a dependence of dexamethasone effect on the gastric erosion formation upon duration of the hormonal action. Gastric erosions were induced by indometha cin (35 mg/kg, sc) in male rats after 24-hour fasting. The rats were given a single injection of dexamethasone at a dose of 1 mg/kg and they underwent the ulcerogenic stimulus (indomethacin) at va rious time points after the hormonal injection (1, 6, 12, 18, 24 hours as well as 3, 5, 7 days). The control rats were given dexamethasone vehicle. In 4 hours after indomethacin injection gastric erosions, corticosterone and blood glucose levels, as well as body and thymus weights were examined. The results obtained demonstrate a dependence ofdexamethasone effect on the gastric erosion formation upon duration of its action: dexamethasone attenuated or aggravated indomethacin-induced gastric erosions depending on the time of its injection. Gastroprotective action of dexamethasone was observed in the case of its injection 1, 6, and 12 hours before indomethacin. The further increase in the time interval caused transformation of gastroprotective action of dexamethasone against ulcerogenic effect. The data obtained suggest that a disturbance of carbohydrate regulation accompanied with the signs of catabolic effects of the glucocorticoid may be responsible for the ulcerogenic action of dexamethasone.