乳头管灌注金黄色葡萄球菌对家兔血清中酶活性的影响

The Effects on the Activities of Enzymes in Serum by Infusing Staphylococcus aureus via Teat Duct in Rabbits

检测和分析乳头管灌注金黄色葡萄球菌前后家兔血清酶活性的动态变化,筛选奶牛乳房炎早期诊断指标。18只健康的怀孕家兔于产后7 d经第4对乳腺乳头管灌注金黄色葡萄球菌建立乳房炎模型。在灌注前2 h与灌注后6、12、24、48、72 h分别采血测定血清中碱性磷酸酶(ALP)、乳酸脱氢酶(LDH)、过氧化物酶(LP)和髓过氧化物酶(MPO)的活性并同时采集乳腺组织观察病理学变化。结果显示,血清酶ALP、LDH和MPO活性在灌注后6～48 h时显著升高(P<0.05),LP活性在灌注后12～48 h时显著升高(P<0.05),4种酶活性均在灌注后24 h时达到峰值;LDH活性变化与不同时相之间的拟合度(R2=0.9704)均大于其他3种酶与不同时相之间的拟合度;LDH活性与乳腺组织损伤程度密切相关。研究结果提示,LDH可以作为乳房炎早期诊断候选指标进一步研究。

In order to screen indicators for earlier diagnosis of diary cow mastitis by investigating the activity dynamic changes of enzymes in serum of rabbits at before and after infusion Staphylococcus aureus through teat canal.Eighteen healthy pregnant rabbits at seven days after parturition were infused with Staphylococcus aureus via teat duct to the fourth pairs of the mammary gland to establish animal model of mastitis.At exactly 2 h before inoculation and 6,12,24,48,72 h after infusion,taking the blood to determine the activity of alkaline phosphatase（ALP）,lactatedehydrogenase（LDH）,lactoperoxidase（LP） and myeloperoxidase（MPO）.At different time after infusion,one rabbit was euthanatized and the mammary glands were removed and fixed for histopathologic evaluations.The results showed that the activity of ALP,LDH and MPO significantly increased within 6-48 h（P〈0.05）,and activity of LP significantly increased（P〈0.05） within 12-48 h after infusion Staphylococcus aureus via teat canal.These four enzymes activities reached peak value at 12 h after infusion.The fitting degree（R2=0.9074） between LDH activity with different time at before and after infusion Staphylococcus aureus higher than other three enzymes.Mammary tissue damage was closely related to the LDH activity.The results suggested that LDH could be as a candidate indicator for earlier mastitis diagnosis to further study.