HISTOLOGICAL EFFECTS OF MELATONIN ON MALE RAT'S ALVEOLAR MACROPHAGES

Abstract

Background: Melatonin is a neuro-hormone of the pineal gland. It increases and enhances immunity, whether in animals or human. The mononuclear – phagocyte system; is a single functional immune unit. The pulmonary alveolar macrophages are one of the most important members included within this immune unit. Objective: This work tried to study the effect of different doses of dietary melatonin on adult rat's pulmonary alveolar macrophages. Methods: Melatonin was supplied to adult rats, for successive 30 days. Rats were divided into 6 groups. Group I was the control. Group II, III, IV, V and VI were given a daily dose of melatonin as 125, 250, 500, 750 and 1000 µg / kg body weight, respectively. After the last day of treatment, the left lung of the rat was removed under anesthesia for histological study.Results: The results showed significant beneficial effects on pulmonary alveolar macrophages by normal therapeutic dosages, whereas with further stepping up doses, significant damaging effects were seen. Conclusion: Dietary melatonin had good effects on the rat's pulmonary alveolar macrophages within therapeutic doses, whereas it had highly damaging changes in overabundance.