The Relationship Between Melatonin and the Immiune Function in Immature Rats

In order to clarify the possible effect of melatonin hormone on immune system, the present study was carried out tostudy the effect of oral administration of melatonin on some immune parameters in adult male rats.The study was carried out at the Department of Physiology, Faculty of Veterinary Medicine, Zagazig UniversityThirty immature male male rats were divided into 3 equal groups. Group (I) maintained as control, Group (11) was subjected to fasting for one day and melatonin was supplemented at the endfasting and continued for 15 days, Group (Ill) was subjected tofasting for 2 days and the melatonin was supplemented (orally bystomach tube at dose of 0.01 mg/lOO g.b.w) at the end of 2°d dayof fasting. The samples were taken after complete course ofmelatonin supplementation of 15 days. Samples from controlanimals were taken at the same time of taking samples fromgroup 11 and Ill. Melatonin was supplementation between 1700slaughtering directly from jugular vein into clean, heparinized tubes and divided into three parts, I St part for total and differential leucocytic count, 2”d part was used for lymphocyteproliferation assay test and the 3rd part was centrifuged at ’3000rpm for 20 minutes and plasma was collected after centrifugationfor assays of interleukin-2 and immunoglobulins. Tissue samplesof spleen, thymus were taken and fixed in 10% formalin for histopathological examination.