【摘要】 40只SD雌性大鼠使之交配受孕。在确定其怀孕后,取35只孕鼠随机分成正常对照组(Con,n=5)、阳性对照组(P,n=15)和实验组(T,n=15)。阳性对照组与实验组内分为3个剂量组,分别为P1、P2、P3组和T1、T2、T3组。实验组大鼠每天按体质量灌喂谷氨酰胺(G lu tam ine,G ln)0.34 mm o l/kg,直至处死,而对照组大鼠灌喂相应体积的生理盐水(PSS)。孕鼠于产后72 h,分别用灭菌PSS(正常对照组)和不同剂量(5、10、50μg)的大肠杆菌内毒素(阳性对照组和实验组)经乳头管灌注到大鼠第4对(腹部)乳腺内。灌注后24 h处死大鼠,取乳腺组织固定,进行组织学观察。观察显示,3个剂量的内毒素均可诱发大鼠实验性乳腺炎,其中P3组大鼠乳腺组织破坏得最为严重。P3组大鼠乳腺组织中肿瘤坏死因子α(TNF-α)浓度、N-乙酰-β-D-氨基葡萄糖苷酶(NAG ase)活力,与正常对照组相比显著升高(P<0.05);T3组大鼠乳腺组织中TNF-α浓度,与P3组相比显著降低(P<0.05)。阳性对照组大鼠乳腺组织中白细胞介素-2(IL-2)浓度,与正常对照组相比有所降低;T3组大鼠乳腺组织中IL-2浓度,与P3组相比显著升高(P<0.05)。与正常对照组相比,阳性对照组与实验组大鼠乳腺组织中碱性磷酸酶(A lka line phosphatase,AKP)活力显著升高(P<0.05)。与正常对照组相比,阳性对照组与实验组大鼠血清中细胞因子和分泌性IgA浓度、酶的活力均无显著变化(P>0.05)。由此表明,灌喂G ln可以抑制乳腺组织内炎性细胞因子TNF-α的释放,减轻炎症对T淋巴细胞增殖反应的抑制,对内毒素诱发的大鼠实验性乳腺炎有一定的保护作用。更多还原

【Abstract】 Forty female rats were mated.After pregnancy was confirmed,thirty-five pregnant SD rats were randomly divided into normal control group（n=5）,positive control group（n=15） and treatment group（n=15）.Positive control group and treatment group were subdivided into P₁、P₂、P₃、T₁、T₂ and T₃ group according to the infusion dosage.Glutamine（0.34 mmol per kg per d） or physiological saline solution（PSS） was administrated by mouth to the rats of the treatment group and control group until they were euthanatized.Either sterile PSS or different amount（5 μg,10 μg,50 μg） of Escherichia coli endotoxin was inoculated into the fourth（abdominal） mammary gland via the teat duct 72 hours after parturition.Exactly 24 hours after inoculation,the rats were euthanatized and the mammary glands were removed and fixed for histopathologic evaluations.Histopathologic examination of mammary gland revealed that any amount of endotoxin can induce experimental mastitis in rats,and the mammary glands of P₃ group had the most severe pathologic lesion.In comparison with those of normal control group,tumor necrosis factor-α（TNF-α） concentration and N-acetyl-β-D-glucosaminidase（NAGase） activity were significantly（（P<0.05）） higher in the mammary glands of P₃ group.While TNF-α concentration in mammary gland of T₃ group significantly（P<0.05） decreased,compared with those of P₃ group.There was significant increase（P<0.05） of interleukin-2（IL-2） in mammary gland of T₃ group as compared with those of P₃ group.In comparison with those of normal control group,alkaline phosphatase（AKP） activity was significantly higher（P<0.05） in the mammary gland of positive control and treatment group.Both cytokine concentration and enzyme activity in plasma had no remarkable change（P>0.05）.The results demonstrated that glutamine can inhibit excessive release of TNF-α in mammary gland,promote proliferation of T lymphocyte and has the protective effect on rat experimental mastitis induced by endotoxin.更多还原