Effects of CpG-ODN on NAGase, MPO and lactoferrin in milk during goat mastitis | CpG-ODN对山羊实验性乳腺炎乳中NAGase、MPO及乳铁蛋白的影响

chinois. 选择同处于泌乳初期的睢宁白山羊6头，产后第5、8天分别向左、右乳区灌注等体积的灭菌PBS和10μg・kg. 1 CpG―ODN（cytosine―phosphate-guanosine dinucleotides），第9天于左、右乳区经乳导管灌注大肠杆菌（2×10. CFU・mL. 1）和金黄色葡萄球菌（2×10. CFU・mL. 1）混合菌液3mL。分别于灌注细菌前0h，灌注后8、16、24、48和72h采集乳样，动态监测乳中N-乙酰-β-D-氨基葡萄糖苷酶（NAGase）和髓过氧化物酶（MPO）的活力及乳铁蛋白含量变化。灌注72h后处死动物，取乳腺组织进行组织学观察。结果显示：灌注细菌后72h，灌注PBS的乳腺腺泡内仍有大量嗜中性粒细胞浸润，但灌注CpG―ODN的乳区已无明显细胞浸润。灌注CpG―ODN侧乳中NAGasc、MPO活性均随时间变化先上升后下降，在24h达到最大值，乳铁蛋白含量则在16h达到最高。灌注PBS的侧乳中NAGase、MPO活性随时间变化表现出相同的规律，但NAGase峰值高于灌注CpG―ODN的一侧，MPO峰值低于灌注CpG―ODN的一侧；乳铁蛋白含量在24h达到最大，峰值也有所升高.上述结果表明，CpG―ODN可以增强乳腺对金黄色葡萄球菌和大肠杆菌联合感染诱导的山羊实验性乳腺炎的非特异性防御能力，减轻乳腺上皮细胞的损伤。[著者文摘]

anglais. Six healthy Suining white goats in their early lactation were infused the same dosage with sterile PBS and 10 μg・kg. 1 CpG-ODN in the mammary left and right on the 5th day of postpartum. On the 8th day the same dosage of PBS or CpG-ODN were infused for the second time. Then on the 9th day, the mammary quarters （both left and right） were infused with 3 mL of 2 ×10. CFU ・mL. 1 Staphylococcus aureus and 2×10. CFU・mL. 1 Escherichia coli per mammary gland respectively. Before （defined as 0h） and 8, 16, 24, 48 and 72 h postinfection, milk samples from both quarters were collected. The activity of N-acetyl-β-D-glueosaminidase （NAGase）, myeloperoxidase （MPO） and the content of lactoferrin （LF） in milk were dynamically monitored. The histopathologic evaluations showed that a large number of polymorphonuclear leukocytes （PMN） were still accumulated in alveoli at 72 h postinfection, but those in the CpG-ODN-treated quarters vanished. In CpG-ODN-treated udder, NAGase and MPO activities increased with the duration of infectin and both peaked at 24 h, the content of LF increased and peaked at 16 h. However in PBS-treated udder, the dynamic changes of NAGase, MPO activities and the content of LF were similar to those in CpG-ODN-treated udder. But the NAGase peak value and the LF content were higher than those in latter and the MPO peak value was lower. The result indicated that the CpG-ODN can enhance the non-special immune response of the mammary gland to mastiffs caused by S. aureus and E. coli infection in goat and reduce the damages to the mammary epitheial cells.