| This experiment is targeted at rabbits(with Vascular chorion placenta,VCP) as the model animal.Through analysis of the immunological conditions of rabbits during its pregnancy and around parturition,the immulogical mechanisms of the maintaining of pregnancy and the starting-up of parturition of animals with vascular chorion placenta is expected to be revealed,and,the knowledge of reproductive physiology and reproductive-transplant immunology broadened.From this series of experiments,we also hope to derive more knowledge to serve as the theoretical basis of the prevention of diseases during pregnancy and the applications of immunology in the reproduction of animals.Female rabbits was synchronously sexual heated and artificially inseminated, with the pregnant mare serum showing the best effect,The ratio of successful artificial insemination as high as 50%,and enough baby rabbits was given birth perfectly heathy.Totol and categarized peripheral blood leucocytes were counted during pregnancy and post parturition period,and the results indicates:The leukocyte and lymphocyte count of pregnant group is not obvious compared with that of the control group.It is at normal level.Three parallel experiments were conducted to survey the quantitative variation of T-lymphocyte in peripheral blood of rabbits during pregnancy and post parturition period,namely Ea,Et test,ANAE+T lymphocyte test,T-Lymphocyte transformation test.Results show:After breeding,the rate of Ea,Et formation,amount of ANAE+ T-lymphocyte and the OD value of T-Lymphocyte transformation decrease gradually until the 25thgestational day(GD),this indicates a decline of the activity of T-lymphocytes and the cellular immunity.For that sake,the ejection of the mother's body to the fetus also declined,this helps to maintain the pregnancy 5 days before parturition the data above begin to ascend,reaching its maximum value on the day of parturition,this leading to an intense ejection to the fetus,which results in the parturition.Then the numerical value of those data decrease rapidly,this maybe caused by the severe depletion during the parturition.This condition should not last too long,the mother's body would recover soon from this catastrophe afterwards.The quantitative variation of B-lymphocyte in peripheral blood of rabbits during pregnancy and post parturition period was surveyed by M'IT(3,4,5-dimethylthiazol-2,5-diphenyl tetrazoliumbromide)chromatometry.Results:The OD value of B-Lymphocyte transformation test(ODVB)increases modestly during early and middle period of pregnancy,this benefits the production of occluding antibody, which occludes the nourish cells in the placenta to avoid the cyto-toxicity of the mother's Lymphocyte and protect the fetus from being ejected by the mother's body. The ODVB begin to decrease 3 days before parturition,which indicates a drop in humoral immunity and an enhancement in cellular immunity,which together inducing the parturition.The ODVB begin to increase on the day of parturition,which reaches its maximum value on the 3th day after parturition.The researchers estimate that much antibody were supplied the newborns through the milk,to enhance their immunity to diseases.The quantitative variation of IL-2 productivity of T-lymphocytes in peripheral blood of rabbits during pregnancy and post parturition period was surveyed by cell proliferation method.Results:After breeding,IL-2 productivity of T-lymphocytes (ILPT)in peripheral blood decreases gradually until 20th GD,this weakened the toxicity of ILPT to the fetus and placenta,thus maintains the pregnancy.ILPT begin to increase 5 days before parturition,reaching its maximum value on the day of parturition,which indirectly indicates that the cellular immunity of the mother were strengthened,hence starting up the parturition.ILPT decreases rapidly after parturition,but still maintains a relatively high level,researchers estimate that the possible reason of this maybe the same as that in the case of T-lymphocytes. |
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