Research On Oviduct Tissue Lesions And Apoptosis In NDV Infected Hens

Recently, genotype VII NDV strain still epidemic in parts of our country, with high incidence and low mortality rate for immunized hen groups. However, infected hens will be eliminated for their declined growth performance and production capability. Attributes to NDV Infection, production level of the peak time hens decreased by 20—30%, it could reach 50% or even stopped for critical hens. At the same moment, the proportion of soft shelled egg、rough eggs and misshapen eggs went up. The rate of fertilization and incubation dropped in normal-appearing eggs. With the Research of oviduct tissue lesions and apoptosis on GenotypeⅦ NDV artificially infected hens, this study revealed the mechanism of oviduct malfunction caused by NDV Infection.Hens aged 25-30 weeks were inoculated in imitating nature infection NDV does. Observing hens’ physical status after infection in 15 days, Executing the hens with typical symptoms at the 1st、3rd、5th、7th、15th day after infection respectively, and Observing pathological change. Oviducts were isolated and cryopreserved in liquid nitrogen and separated by infundibulum, magnum, isthmus, uterus and vagina. Hematoxylin-eosin staining、TUNEL staining、Caspase-3 activity enzyme were used to processes all isolated parts, and observing the consequence.As can be seen from Hematoxylin-eosin staining, exfoliation and necrosis were seen in columnar epithelial cells, or even breakage happened in serosa. In gland tissue, hyperemia, hemorrhage were seen. In Glandular epithelial cell, exfoliation, gland gap enhance, infiltration of inflammatory cells were been observed, and parts of gland dissolved with obscure contour. After 3-5 days the tissue was highly lesions by NDV. In infundibulum, magnum and uterus, the damage became more typical than the other parts by horizontal comparison. TUNEL staining showed that Tissue apoptosis happened in oviduct, especially in infundibulum, isthmus, uterus with highest apoptosis degree.caspase-3 activity enzyme illustrated that caspase-3 enzyme activity was higher than other normal tissue, also, magnum(P<0.01,highly significant)and uterus(P<0.05,significant) display more topical than others parts.It is the attack stage of disease during the period of 24-48 h after NDV infected hens, the highest damage degree showed around 72h-120 h, the damage degree went to stable and recovered slowly after 120 h. damage recovered and hen groups were recovered after 240h; Under the effects of NDV, pathological damage and tissue apoptosis occurred in all parts of oviduct, some important functional parts, like magnum with protein secreting, isthmus with shell membrane shaping, uterus with eggshell forming, has serious damage. Severe dysfunction took place due to the damage of old tissue frame. Though damage tissues recovered, its function could not return back to the same level before it damaged. In conclusion, this study explains the interaction between the drop in egg production and NDV infection,that is in the process of NDV proliferation induced oviduct tissue apoptosis, causing tubal function seriously obstacle.