家兔乳头管灌注脂多糖诱发血清急性期蛋白的动态变化

Dynamic changes of acute phase proteins concentrations in serum induced by LPS via teat in rabbits

检测和分析经乳头管灌注脂多糖(LPS)前后家兔血清急性期蛋白含量的动态变化。11只泌乳家兔(产后7d)经乳头管灌注LPS建立乳房炎模型,在灌注前2h,灌注后6、12、24、48、72h和5、7d分别测定血清中结合珠蛋白(HP)、C-反应蛋白(CRP)和白蛋白(ALB)含量,同时取乳腺组织观察病理变化。组织病理学结果显示,灌注LPS后6h后乳腺组织出现病理变化,腺泡腔中观察到嗜中性粒白细胞;灌注24h时组织损伤加重,乳腺组织结构紊乱,浸润大量嗜中性粒白细胞;48h后乳腺组织开始自我修复,7d时恢复正常。灌注LPS前血清中HP含量低于检出限,灌注LPS后6h时HP含量显著升高(P<0.05),12h时达到峰值,48h开始显著降低(P<0.05);CRP含量在灌注LPS后6～72h内显著升高(P<0.05),12h时达到峰值,72h后逐渐降低,5d时恢复到健康水平;ALB含量在灌注LPS后12～72h内显著降低(P<0.05),5d时恢复到健康水平。结果表明,HP、CRP和ALB含量在灌注LPS前后发生了规律性的变化,其中HP含量对LPS诱导的急性乳房炎反应敏感,提示HP可作为评价乳腺组织炎症程度和乳房炎的早期诊断指标。

In order to investigate the dynamic variations of lipopolysaccharide（LPS） induced acute phase protein（APP） concentrations of serum in rabbits,eleven lactating rabbits（7th day after parturition） were challenged by infusing LPS（75 μg/kg body weight） into the fourth mammary gland via the teat duct.The concentrations of haptoglobin（HP）,C-reactive protein（CRP） and albumin（ALB） in rabbits serum were determined at 2 h before infusion LPS and at 6,12,24,48,72 h,5,7 d after infusion.At the same time,pathological changes of mammary gland tissue were observed.Histopatholgic examination revealed that mammary gland had pathological changes at 6 h after infusion LPS,but alveolar structures were still discernible,numbers of polymorphonuclears（PMNs） were present in alveoli.The mammary gland had more severe pathological lesion at 24 h after infusion,the normal alveolar structures were lost and infiltrated with numerous PMNs.The affected mammary gland displayed self-regenerating at 48 h,returning to normal at 7 d.Concentration of HP before infusion LPS was lower than detected limit,increasing significantly at 6 h after infusion（P0.05）,peaking value at 24 h,decreasing significantly at 48 h（P0.05）.Concentration of CRP increased significantly 6-72 h after infusion（P0.05）,peaking value at 12 h,decreasing gradually at 72 h,returning to normal level at 5 d.Concentration of ALB decreased significantly 12-72 h after infusion（P0.05）,returning to normal level at 5 d.The results suggest that concentrations of HP,CRP,ALB displayed regular changes at different time before and after infusion LPS,in which concentrations of HP is more sensitive to acute bovine mastitis which induced by LPS,indicating that HP could be as a candidate indicator to value the severe degree of inflammation of mammary gland and for earlier diagnosis of mastitis.