Dynamic Observation Of Ghrelin Distribution In The Normal And Duck Hepatitis Virus Infection Ducklings

Objective:To study the distribution and positioning of ghrelin in 1 to 49 day-old duckling by the method of immunohistochemistry,analysis the distribution and change characteristic between control group and experimental group,provide morphological basis to further understand the environment within the body how to maintain the stability, and also helps to understand the complex control of nerve-endocrine-immune network.Method:1-day-old yingtaogu duckling 200 feathers were randomly divided into two groups:the control groups(the normal groups) of 80 feathers,experimental groups (infection with DHV group) of 120 feathers.In four days,vaccinated duck hepatitis virus by the leg muscles(0.lml/feather,10^-3.5LD₅₀/0.2ml),duplicated DHV pathological model. And control group injected with normal saline(0.1ml/feather).Observe the duckling state every day,record incidence and clinical symptom.Take 6 feathers randomly in control groups on 1d,3d,5d,7d,9d,11d,14d,21d,28d,35d,42d,49d before feeding.Take 6 feathers on 5d,7d,9d,11d,14d,21d,28d,35d,42d,49d from the experimental groups and deal with in the same method. Ducklings were sacrificed by vena jugularis haemospasia.Then remove brain,liver, stomachus glandularis,thymus gland,pituitary gland,spleen,pancreas,bursa of fabricius,and fixed them in 10%formalin solution and processed by routine protocols for embedding in paraffin wax.The paraffin section was 4μm thick.Divided the paraffin section into two groups,one group was make conventional hematoxylin-eosine staining(H.E)(sticks tablet by the protein glycerine),and another group was make streptavidin-biotinperoxidase complex staining(SABC)(sticks tablet by the poly-L-lysine).Results:Pituitary,stomach,pancreas,spleen,thymus and bursa of fabricius of control groups have positive cells distribution on 1-day-old by SABC staining.The vessel wall of spleen,thymus,bursa of fabricius of connective tissue cells have have positive cells distribution also.The ghrelin positive cells have different characteristics.in different organizations.In spleen,the positive cell are plasma cells,monocytes,lymphocytes,and epithelial cells.In the thymus are dendritic cells,lymphocytes,trabecular epithelial cells; in the bursa of fabricius are trabecular epithelial cells;in the stomachus glandular are gastric gland cells;in the pancreas and pituitary cell types were unable to determine. ghrelin is mainly distributed in the cytoplasm,also distributed in the dendritic cells, connective tissue cells,monocytes nucleus,negative control section have no ghrelin positive cells distribution.The positive cells in different organizations have different staining speed.In pancreas and spleen,the positive cells staining fastest.Ghrelin positive cells distribution types of experimental group were same to that in the control group.Optical density values:the optical density of the positive cells in control group increased with age.The change of ghrelin average optical density value in experimental group is closely related to the inoculation time.The tendency of the ghrelin average optical density value in positive cells is different in each organization.The average optical density of positive cells that are thymus,bursa of fabricius,and spleen organization increased rapidly on 5d in experimental group,the peak form rather late that are the average optical density value of the positive cells in the stomachus glandular and pancreas organizations,which of the pituitary does not change obviously.HE staining results:The live,pancreas,spleen,kidney and other organizations of test group,have obvious Hemorrhagic necrosis pathological change,especially liver lesions.24h after infection with DHV-I,the liver,spleen,thymus showed hemorrhage, necrosis of the pathological changes of inflammation,normal liver small plate vague or even disappear,spleen red and white pulp boundaries was not obvious.After 48h infection,in the liver that infiltration of inflammatory cells,spleen white pulp,thymus and bursal follicular medulla lymphocytes significantly reduced.The bile capillary and splenic corpuscle are hyperplasyin after 72h infection.Conclusion:In physiological state,pituitary,stomach,pancreas,spleen,thymus and the bursa of Fabricius have ghrelin positive cells distribution.In addition,the blood vessel of spleen,connective tissue of thymus,bursa of fabricius cells have positive ghrelin distribution also.Present significantly tissue-specific.The change of ghrelin average optical density value in experimental group is closely related to the inoculation time.5d of experimental group,the average optical density value of the positive cells peak form late in the stomachus glandular and pancreas organizations,which of the pituitary does not change obviously.