MELATONIN PROTECTS THE INTEGRITY OF GASTRIC STRUCTURE FROM A STERILE TISSUE INJURY AND AUGMENTS BOTH MONONUCLEAR AND POLYMORPHONUCLEAR PERIPHERAL BLOOD CELLS INDUCED BY THE INJURY IN WISTAR ALBINO RATS

Peptic ulcer is a common upper gastrointestinal disease that remains a major public health problem. Gastric ulceration caused by Nonsteroidal Anti-Inflammatory Drugs (NSAID), stress and alcohol are the common causes of gastric ulcer formation in humans following helicobacter pylori bacterial infection of the stomach. The neurohormone, melatonin was reported to protect against NSAID- and stress-induced gastric lesions. We sought to determine whether melatonin, which is known to have antioxidant effects and induces systemic leukocyte mobilization, can protect the gastric structure from a sterile tissue injury. Equally divided melatonin or vehicle pre-treated Albino rats (N = 20) were subjected to sterile tissue injury of gastric ulceration using hypertonic sodium chloride solution. Melatonin treatment significantly protected the animals from gastric lesions induced by hypertonic salt compared to control vehicle-treated animals that show formation of gastric lesions in all examined rats. In addition, melatonin treatment significantly increased sterile tissue injury induction of both mononuclear and polymorphonuclear peripheral blood cells. We conclude that melatonin protects sterile tissue injury-induced gastric lesions and augments white blood cell populations in response to this type of tissue injury.