Light and Scanning Electron Microscopic Study of 5- Fluorouracil-Induced Mucosal Injury in the Gastric Fundus and the Possible Protective Role of Omeprazole in Adult Male Albino Rat

Introduction: Administration of chemotherapy in a wide variety of cancers is associated with various side effects, with structural affection of gastrointestinal tract being a major clinical concern and a major cause of cancer treatment-related morbidity. Aim of the work: This current study was performed to assess the light and scanning electron microscopic changes of 5-fluorouracil (5-FU) induced cytotoxicity on the mucosa of gastric fundus in male albino rats and to assess the possible protective role of omeprazole. Materials and methods: Forty adult male albino rats were divided into four groups: Group I (control rats), Group II administrated (10 mg/kg) omeprazole orally via gastric tube/ once daily for 5 consecutive days, Group III injected IV with (50 mg/kg) 5-fluorouracil once daily for 5 consecutive days and Group IV received 5fluorouracil as group III + omeprazole as group II. At the end of the experiment, specimens from gastric fundus mucosa were processed for light and scanning electron microscopic study. Results: Light microscopic examination in 5-FU group revealed many changes such as, erosion at pits of the mucosa with destructed surface mucous cells with distorted nuclei and intra-luminal exfoliated cells, vacuolated parietal cells with pyknotic and karyolitic nuclei and distorted chief cells with apical migration of their nuclei. Also, the lamina propria showed inflammatory cell infiltration and extravasated RBCs. Specimens from group IV revealed mild mucosal injury in gastric fundus as compared to 5-FU-treated rats. Scanning electron microscopy examination of 5-FU-treated rats revealed loss of demarcation between mucous cells, many necrotic areas in the mucosa with umbilicated apices. Other specimens showed complete shedding of mucosal surface leaving irregular wide openings of the gastric pits with a shape of honeycomb. Scanning electron specimens in group IV revealed apparent normal fundus mucosal surface. However, mild changes in the mucosal surface were observed in some specimens. Conclusion: It is concluded that concomitant administration of omeprazole with 5-FU has a protective effect against 5-FU-induced structural changes in the mucosa of stomach fundus.