The Effects Of Melatonin On The Ducks' Immune Function With Different Illumination

The content of melatonin was different by control illumination. Used WBC, RBC, hemoglobin checking, RIA, ELISA, molecular cloning and RISH methods to study the relationship between the PBC, cytokine, lymphocyte and the melatonin.We also studied the expression of Mel1a, Mel1b and Mel1c in ducks'immune system. The result as follow:The level of the melatonin was decreased significantly by long illumination and the difference were significantly(P<0.01)compared to control group (12h).With the increasing of melatonin, the content of leukocyte(P<0.01), erythrocyte(P<0.01),hemoglobin(P<0.01), IL-2(P<0.05), IL-6(P>0.05), TNF-α(P>0.05),γ-IFN(P<0.01), IgG(P<0.01), CD3+CD4+ (P<0.01), CD3+CD8+ (P<0.01) and Bu-1a+ (P<0.01) all increased; with the decrease of melatonin, the content of leukocyte (P<0.01), erythrocyte (P<0.01), hemoglobin (P<0.05), IL-2(P<0.05), IL-6 (P>0.05), TNF-α(P>0.05),γ-IFN (P<0.01), IgG (P<0.05), CD3+CD4+ (P<0.01), CD3+CD8+ (P<0.01) and Bu-1a+(P<0.01) all decreased.The three melatonin receptor subtypes partial gene was amplified by RT-PCR from duck first time. They were 603 bp, 468 bp and 504 bp. The PCR product was sequenced and analyzed subsequently. The results indicated that the gene homology of dMel1a, dMel1b and dMel1c between three types MR of chicken were 93.5%, 95.9% and 95.0%.We prepared digoxigenin -labele MR cDNA probe and detected the MR in duck's spleen, thymus and cloacal bursa by in situ hybridization. The result indicated that the three subtypes MR all expressed in duck's spleen, thymus and cloacal bursa. The MR express in T and B lymphocyte of above-mentioned tissues. From these cells, we can see the positive signals in the nucleus and cytoplasm. The rule of the MR distribution was: 18h>12h>6h and Mel1a>Mel1c >Mel1b.