茶多酚对高蛋氨酸饮食诱导大鼠纤维蛋白溶解功能损伤的影响

The effects of tea polyphenols on the injury of fibrinolytic functions induced by high-methionine dietary in rats

目的研究茶多酚（teapolyphenols，TP）对蛋氨酸诱导大鼠纤维蛋白溶解功能损伤的保护作用。方法取成年雄性Wistar大鼠50只，按体重分层随机分为对照组、模型组，以及TP低、中和高剂量组。对照组喂饲正常基础饲料，模型组及TP组均喂饲3％高蛋氨酸饲料，同时TP低、中、高剂量组每天经灌胃分别给予50、100和200rag／kg的TP，灌胃体积均为0．5ml／100g，对照组和模型组给予等体积蒸馏水。8周后断头处死大鼠，采用免疫组织化学链霉亲和素．生物素．过氧化物酶复合物（strept—avidin—biotincomplex，SABC）法测定大鼠主动脉弓组织型纤溶酶原激活物（tissue．typeplasminogenactivator，t-PA）和纤溶酶原激活物抑制剂-1（type-1plasminogenactivatorinhibitor，PAI-1）蛋白表达结果；ELISA法测定血浆中t-PA和PAI-1含量；RT—PCR法测定胸主动脉t-PA和PAI-1mRNA水平。结果实验结束后，对照组、模型组及TP低、中、高剂量组主动脉弓中t-PA蛋白表达量分别为133．03±10．14、95．46±11．08、111．97±11．91、130．23±10．80、139．39±9．41（F=14．15，P〈0．01），PAI-1蛋白表达量分别为90．91±8．67、166．76±12．18、139．63±12．71、134．66±13．19、109．49±10．82（F=31．44，P〈0．01）；血浆中tPA含量分别为（10．69±1．26）、（6．13±0．92）、（8．56±1．19）、（9．69±0．92）、（11．97±1．08）ng/ml（F=41．98，P〈0．01），PAI-1含量分别为（6．31±0．81）、（16．98±1．27）、（11．39±0．82）、（8．46±0．67）、（8．08±0．91）rig／ml（F=207．74，P〈0．01）；t-PAmRNA水平分别为1．12±0．02、0．75±0．14、1．01±0．09、0．95±0．08、1．05±0．13（F=5．77，P〈0．05）；PAl-1mRNA水平分别为1．25±0．11、1．74±0．06、1．23±0．05、1．09±0．14、1．23±0．04（F=23．56，P〈0．01）。结论TP能够调节t-PA和PAI-1的转录及蛋白水平，维持t-PA和PAI-1的平衡状态，修复高蛋氨酸饮食诱导的大鼠纤维蛋白溶解功能损伤。

Objective To study the protective impact of tea polyphenols （TP） on the injury of fibrinolytic functions induced by high-methionine dietary in rats. Methods 50 male Wistar rats were divided by stratified based on body weight into 5 groups with 10 in each group： namely control group, model group,low-dose TP group, medium-dose TP group and high-dose TP group. The rats in model group and TP groups were fed with 3% methionine dietary, control group rats with routine diet. In addition, rats in low- dose,medium-dose and high-dose TP groups were treated with TP at 50,100 and 200 mg/kg dosage respectively by gavages every day, control group and model group rats were given with same amount distilled water. The animals were sacrificed after 8 weeks. The levels of tissue-type plasminogen activator （t-PA） and type-1 plasminogen activator inhibitor（PAI-1） in plasma were determined by ELISA assays,mRNA levels of t-PA and PAI-1 in aortic arch were detected by RT-PCR, t-PA and PAI-1 expression in aortic arch were detected by immunohistochemistry strept-avidin-biotin complex （SABC）. Results After experiment, the t-PA expression of aortic arch in control group, model group,low-dose TP group, medium-dose TP group andhigh-dose rip group were 133.03 ± 10. 14,95.46 ± 11.08,111.97 ± 11.91,130. 23 ± 10. 80,139.39 ± 9. 41 （F = 14. 15, P 〈 0. 01 ）, respectively, and the PAI-1 expression were 90. 91 ± 8.67,166. 76 ± 12. 18, 139. 63 -＋ 12. 71,134. 66 ± 13.19,109. 49 ± 10. 82 （F = 31.44 ,P 〈 0.01 ）. The t-PA concentration of plasma were （ 10. 69 ± 1.26）, （6. 13± 0. 92）, （ 8.56 ± 1.19）, （ 9. 69 ± 0. 92）, （ 11.97 ± 1.08 ） ng/ml, respectively （ F = 41.98, P 〈 0. 01 ）, and the PAI-1 concentration of plasma were （6. 31 ＋ 0. 81 ）, （ 16. 98 ± 1.27 ）, （ 11.39 ± 0. 82）, （ 8.46 ± 0. 67 ）, （ 8.08±0. 91 ） ng/ml, respectively （ F =207. 74, P 〈 0. 01 ）. The mRNA levels of t-PA in aortic arch were 1.12 ±0.02,0.75 ±0. 14,1.01 ＋0.09,0.95 -＋0. 08,1.05 ＋0. 13（F= 5.77, P 〈 0. 05 ）, and the mRNA levels of PAI-1 in aortic arch were 1.25 ± 0. 11,1.74± 0. 06,1.23 ± 0. 05, 1.09± 0. 14,1.23 ± 0. 04 （ F = 23.56, P 〈 0. 01 ）. Conclusion The results indicate that TP seems to have regulatary function on transcription and protein levels of t-PA and PAI-1, in addition to maintaining the balance between PAI-1 and t-PA and healing the injury of fibrinolytie functions in rats induced by high- methionine dietary.