CAJ | 학술논문

研究重组大肠杆菌不耐热肠毒素B亚单位( rLTB)在鸭体内的吸收代谢及组织分布,为rLTB的临床应用安全性提供依据。试验鸭分别肌注1,50,100 mg/kg rLTB后,以神经节苷脂GM1酶联免疫吸附法( GM1-ELISA)测定注射后不同时间点鸭血清中的rLTB含量；连续3次肌注rLTB后,观察临床症状和剖检病理变化,并采集心脏、肝脏、脾脏、肺脏、肾脏和大脑制备组织切片,HE染色观察组织病理学变化,免疫酶组织化学染色观察rLTB在各脏器内的分布及含量变化。结果表明：鸭血清中的rLTB含量变化及维持时间与rLTB注射剂量呈正相关。1 mg/kg注射组2 h达到峰值,维持至6 h开始下降,24 h后基本检测不到；50,100 mg/kg注射组分别于2 h和1 h达到峰值,并均维持至12 h才开始下降,48 h后基本检测不到。 HE染色切片显示50 mg/kg注射组肝细胞轻度浊肿变性,肺脏轻微炎症；100 mg/kg注射组肝细胞浊肿变性明显、肺脏重度炎症、脑组织出现局灶性坏死。免疫组化染色结果显示,在被检脏器中均检出rLTB,以大脑含量最高,脾脏和肝脏次之,心脏和肺脏检出量低。 rLTB大剂量肌肉注射可引起鸭一定的组织学病变,对鸭的安全使用剂量应不超过50 mg/kg。
연구중조대장간균불내열장독소B아단위( rLTB)재압체내적흡수대사급조직분포,위rLTB적림상응용안전성제공의거。시험압분별기주1,50,100 mg/kg rLTB후,이신경절감지GM1매련면역흡부법( GM1-ELISA)측정주사후불동시간점압혈청중적rLTB함량；련속3차기주rLTB후,관찰림상증상화부검병리변화,병채집심장、간장、비장、폐장、신장화대뇌제비조직절편,HE염색관찰조직병이학변화,면역매조직화학염색관찰rLTB재각장기내적분포급함량변화。결과표명：압혈청중적rLTB함량변화급유지시간여rLTB주사제량정정상관。1 mg/kg주사조2 h체도봉치,유지지6 h개시하강,24 h후기본검측불도；50,100 mg/kg주사조분별우2 h화1 h체도봉치,병균유지지12 h재개시하강,48 h후기본검측불도。 HE염색절편현시50 mg/kg주사조간세포경도탁종변성,폐장경미염증；100 mg/kg주사조간세포탁종변성명현、폐장중도염증、뇌조직출현국조성배사。면역조화염색결과현시,재피검장기중균검출rLTB,이대뇌함량최고,비장화간장차지,심장화폐장검출량저。 rLTB대제량기육주사가인기압일정적조직학병변,대압적안전사용제량응불초과50 mg/kg。
E. coli heat-labile enterotoxin B subunit ( rLTB) exerts most effective adjuvant effects on mucosal immune responses. In order to elucidate the dynamic and the safety of rLTB for clinical use in duck,the concentra-tions of rLTB in sera,histopathological changes and tissue distribution of rLTB were examined. Ducks were bled pri-or to injection and at different time intervals post-intramuscular injection (IM) with 1,50,100 mg/kg rLTB,respec-tively. GM1-ELISA was applied for the determination of rLTB concentration in sera. The autopsy of ducks was con-ducted at different time points after IM of rLTB once a day,3 times in a row. Samples of heart,liver,spleen,lung, kidney and brain were fixed in 10% paraformaldehyde and the tissue sections were examined after coloration with haematoxylin and eosin(HE) or immunohistochemical(IHC) staining. The result showed that there was positive correlation between concentration and duration of rLTB in sera and the dosages of application. In 1 mg/kg group the amount of rLTB peaked at 2 hour post injection ( HPI) ,and started to decline at 6 HPI,and could not be detected at 24 HPI. In 50 mg/kg group and 100 mg/kg group the peak were achieved at 2 HPI and 1 HPI,respectively and began to decrease at 12 HPI,and beyond the detection limit at 48 HPI. The slight cloudy swelling and degeneration of hepa-tocellular,inflammatory cell infiltration in lung were observed in 50 mg/kg group ducks. Obvious cloudy swelling and degeneration of hepatocellular,severe inflammatory cell infiltration in lung and focal necrosis in brain tissue were ob-served in 100 mg/kg group. IHC staining results showed that rLTB was deteceted in all 6 kinds of examined organs and the highest amount rLTB was observed in brain. The conclusion is that the high dosage of rLTB may cause histo-logical lesions and the rLTB should be used under 50 mg/kg for safe in duck.