Abstract
AIM: To reinvestigate the characteristics of reserpine-induced gastric mucosal lesions (GMLs). METHODS: The GML-inducing effect of reserpine and the time-course of recovery from reserpine-induced GMLs were examined in Sprague-Dawley (SD) rats. The GML-inducing and blood pressure-decreasing effects of Compound Hypotensive Tablets (CHTs) were investigated in spontaneously hypertensive rats (SHRs). Intracerebroventricular (icv) injection and vagotomy were performed to verify the central vagal mechanism in reserpine-induced GMLs. RESULTS: Single intraperitoneal (ip) injections of reserpine (0.25, 0.5, 1, 2, 4, and 6 mg/kg) dose-dependently induced GMLs in SD rats. Both single and repeated (2 weeks) oral administrations of reserpine led to slight GMLs at doses of 24 mg/kg and 10 mg/kg, respectively. Blood pressure was significantly decreased in SHRs after 2 months of CHT administration (0.01 and 0.03 mg/kg; doses were expressed as the amount of reserpine in the CHT). CHT doses of 0.3 mg/kg induced GMLs, but 0.1 mg/kg did not. Examining the time course of recovery from GMLs, severe GMLs occurred 18 h after ip reserpine (4 mg/kg), obviously lessened at 1 week and healed spontaneously at 3 weeks. Intracerebroventricular injections of reserpine caused GMLs at much lower doses (0.08 and 0.4 mg/kg), and reserpine-induced GMLs were greatly inhibited by vagotomy, suggesting the involvement of a central vagal mechanism. CONCLUSION: Reserpine-induced GMLs were dose-dependent, and the lesions healed spontaneously within 3 weeks. Long-term treatment with CHT at doses adequate to decrease blood pressure will not induce GMLs. A central vagal mechanism was involved in reserpine-induced GMLs.