Detrimental effects of oestradiol on cysteamine-induced gastroduodenal ulceration in the female rat

The actions of the female sex steroid, oestradiol on cysteaminc-induced muc osal ulceration has been evaluated in female Wistar rats. Administration of cysteamine (400 mg.kg(-1), s.c.) provoked macroscopic gastroduodenal mucos al injury (assessed planimetrically) and an increase in microvascular perme ability (assessed by the extravasation of radiolabeled albumin) in the stom ach and duodenum, determined 24 h later. Ovariectomy (2 weeks before cystea mine) reduced gastroduodenal macroscopic injury, and albumin extravasation following cysteamine challenge. Administration of oestradiol (1-5 mg.kg(-1) , as an i.m. depot 1 week before cysteamine) dose-dependently augmented gas tric and duodenal macroscopic mucosal lesions and microvascular permeabilit y provoked by cysteamine. These findings indicate that oestradiol can exace rbate gastroduodenal ulceration and microvascular injury. (C) 1999 Elsevier Science Ltd. Published by Editions scientifiques et medicales Elsevier SAS .