Introduction: Irritable bowel syndrome (IBS) is a functional disorder characterized by dysregulated immune and inflammatory pathways. Its symptoms are most prominent in postmenopausal women suggesting that female sex hormones withdrawal may contribute to it.
Objective: To evaluate the effect of estrogen and progesterone on the ileum of experimentally induced IBS in ovariectomized rats using histological and immunohistochemical methods.
Materials and Methods: Sixty adult female albino rats were divided equally into 6 groups: Group I: control group, Group II: IBS group, Group III: ovariectomized (OVX) IBS group, Group IV: OVX IBS Estrogen group, Group V: OVX IBS Progesterone group, Group VI: OVX IBS Estrogen & Progesterone group. Bilateral ovariectomy was performed in groups III, IV, V & VI to induce experimental menopause. In control and IBS groups, rats underwent the same surgical procedure but without removal of the ovaries. Two weeks after surgery, all rats except control were submitted to water avoidance stress (WAS) exercise for 10 days to induce IBS. The same procedure was done for control rats in an empty water tank. Simultaneously, groups IV, V & VI were given daily subcutaneous injections of estrogen or progesterone or both respectively for continuous 14 days. Then, rats were sacrificed and paraffin ileum sections were prepared and stained with H&E, Alcian blue and Toluidine blue stains and immunohistochemical staining against claudin-1. This was followed by morphometric and statistical analysis.
Results: Groups II & III showed extensive damage in ileum structure associated with depletion of goblet and Paneth cells and a significant increase in mast cells and claudin-1 level. On the other hand, groups IV, V and VI revealed apparently normal ileum structure and increased goblet and Paneth cells with a significant decrease in mast cells and claudin-1 level.
Conclusion: Estrogen and Progesterone had regenerative effects on histological structure of the ileum against experimentally induced IBS in ovariectomized rats.