Preventive Effects Of Granulocyte Colony-Stimulating Factor Precondition On Mice With E.Coli Mastitis

Mastitis is a common disease of dams,especially the dairy cow mastitis causing serious economic losses to farmers.Afetr perinatal cows given birth, WBC reduce,especially the significant decrease of neutrophils is key factor of the cause of postpartum cows infected with diseases such as mastitis and endometritis. Granulocyte colony stimulating factor is the main grain is involved in regulating bone marrow hematopoietic cytokines, can promote grain in bone marrow progenitor cell proliferation, differentiation, and increase the number of neutrophils in peripheral blood and promote mature neutrophils walk, eat, sterilization ability and the adhesion of foreign matter, therefore granulocyte colony stimulating factor could be as drug prevention and control of dairy cow mastitis. Test through the establishment of e. coli mastitis model in mice, granulocyte colony stimulating factor on mice of e. coli mastitis prevention effect.Method:(1) Select 8-10 day of lactation of Primiparous Kunming mice 24, were randomly divided into 4 groups, which were respectively given 50μL (25μL/side) three different density (Ⅰ,Ⅱ,Ⅲ) suspension E.Coli (1.5 ×105CFU/mL,1.5× 107CFU/mL,1.5 X 109CFU/mL) by injecting to the forth mammary glands, bacteria liquid Group IV infusion equivalent in sterile saline, we ascertain the best of density suspension of E.coli through observing the clinical manifestation and a routine blood test. (2) Select 120 lactating mice (8-10d were randomLy selected) and divided into five groups (Ⅰ, Ⅱ, Ⅲ, IV and V), the Ⅰand Ⅱ groups were given 50 μL normal saline, while the Ⅲ,Ⅳ and V were given different dose of rhG-CSF, respectively 10μg/kg,20μg/kg and 30μg/kg. After injecting 24h, the I group was given 50μL normal saline,and the Ⅱ, Ⅲ. IV and V were given group was 50 μL E.coli at concentration of 1.5×107 CFU/mL. In breast perfusion Hou of Oh, and 24h, and 72h,120h, sampling of randomly selected in each group 6 mice, We observe the clinical symptoms, histopathologic changes of the forth mammary glands, the routine blood test and the level of the TNF-a to assess whether the rhG-CSF could prevent the mammitis conducted by E.coli.Result:(1) E.coli mastitis in mice model:attack bacteria after 24h, compared with group IV, the mice serum TNF-α of group Ⅰ, Ⅱ and Ⅲ increased significantly (P<0.01); the serum TNF-α of Ⅱ and Ⅲ was higher than Ⅰ significantly (P<0.01); the serum TNF-α of Group Ⅲ was higher than group Ⅱ significantly (P<0.01);Ⅱ of mammary gland hyperaemia of widespread, accompanied by bleeding, breast swelling, harden, with pale yellow inflammatory exudate and curd piece; Acinus cavity and lobular interstitium in neutrophils significantly increased, epithelial cells, necrosis, gland bubble structure disorder with unclear boundaries surrounding tissue, interstitial hyperemia, hemorrhage, a typical breast inflammation;Ⅰ set of breast lesions is group Ⅱ of mild, group Ⅲ more serious than group Ⅱ breast lesions:group IV no exception on breast lesions. (2) The protective effect of rhG-CSF on E.coli mastitis in mice:the mice of group Ⅲ reduce appetite slightly, coat is a bit disheveled, nipple is red; Mammary gland hyperaemia, slightly swelling; Acinus cavity and interstitial inflammatory cell infiltration; Oh,24h,72h,120h, the WBC and GRA of group Ⅲ were higher than that of group I and group II significantly (P<0.01). Normal mental mice group IV, breast redness, swelling, pain and other clinical symptoms are weak; Mammary gland mild hyperemia, no obvious swelling; Breast tissue structure is clear, neat epithelial cells; Oh,24h,72h,120h, the WBC and GRA of group IV were higher than that of group Ⅰ,Ⅱ, III significantly (P<0.01); 24h-120h, the clinical symptoms of 3 mice of group IV disappeared gradually, the spirit and appetite of group V are good, mammary gland organization structure is clear, neat epithelial cells, some acini is full of milk, no obvious tissue damage caused by mastitis; Oh,24h,72h,120h, the WBC and GRA of group V were significantly higher than group Ⅰ, Ⅱ, Ⅲ, Ⅳ (P<0.01); 120h, the clinical symptoms of group V disappeared basically.Conclusion:(1) Lactation 8-10 days of primiparous Kunming mice, the fourth of papillary perfusion 1.5 ×107CFU/mL E.coli 25ul/side can successfully constructed mouse mastitis model. (2) 20 μg g/kg,30μg g/kg body weight in mice subcutaneous 0.1mL of rhG-CSF, which could improved the ability of mice to resist the E.coli infection, and conducted a good prevention.