[The effects of tea polyphenols on the injury of fibrinolytic functions induced by high-methionine dietary in rats].
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 and high-dose TP 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).


CONCLUSIONS
The results indicate that TP seems to have regulatory 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 fibrinolytic functions in rats induced by high-methionine dietary.
Department of Child Health, Wuxi Maternal and Child Health Hospital, Wuxi 214002, China.
Jing-jing
JJ
Pei
Shuai
S
Guo
Cui-li
CL
Zhang
Li-hua
LH
Yu
Zhen-ping
ZP
Zhu
Ke-qin
KQ
Xie
Xiu-lan
XL
Zhao
D000818:Animals; D004032:Diet; D005342:Fibrinolysis / Q000187:drug effects*; D008297:Male; D008715:Methionine / Q000009:adverse effects*; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood; D059808:Polyphenols / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D013662:Tea / Q000737:chemistry; D010959:Tissue Plasminogen Activator / Q000097:blood
D017395:Plasminogen Activator Inhibitor 1; D059808:Polyphenols; D013662:Tea; D008715:Methionine; D010959:Tissue Plasminogen Activator