AIM: To investigate the changes in plasminogen activity level during mesenteric ischemia. METHODS: We performed laparotomy in 90 female Wistar-Albino rats (average weight 230 g). In sham groups (SL) (GroupsⅠand Ⅱ) t...AIM: To investigate the changes in plasminogen activity level during mesenteric ischemia. METHODS: We performed laparotomy in 90 female Wistar-Albino rats (average weight 230 g). In sham groups (SL) (GroupsⅠand Ⅱ) the superior mesenteric artery (SMA) and vein (SMV) were explored, but not tied. In SMA groups (Groups Ⅲ and Ⅳ) the SMA was ligated, and in SMV groups (Groups Ⅴ and Ⅵ) the SMV was ligated. On re-laparatomy 2 mL of blood was drawn at 1 h in groupsⅠ, Ⅲ and Ⅴ, and at 3 h in groups Ⅱ, Ⅳ and Ⅵ. Plasminogen levels were assessed and comparisons were made between groups and within each group. RESULTS: The mean plasminogen activity in the SL group was significantly higher than SMA (25.1 ± 10.8 vs 11.8 ± 4.6, P < 0.001) or SMV (25.1 ± 10.8 vs 13.7 ± 4.4, P < 0.001) groups both at 1 h and at 3 h (29.8 ± 8.9 vs 15.1 ± 5.7, P < 0.0001; 29.8 ± 8.9 vs 14.2 ± 2.9, P < 0.0001). There were no significant differences between the values of SMA and SMV groups at 1 h (P = 0.28) and at 3 h (P = 0.71). In each group, plasminogen activity levels did not change significantly between the two measurements performed at 1 h and 3 h. CONCLUSION: We conclude that blood plasminogen activities decrease during early phases of both arterial and venous mesenteric ischemia which may be a useful marker for early diagnosis.展开更多
Objective. To measure the circulating levels of thrombomodulin (TM) and plasminogen activator inhibitor type- I (PAI- I) in women with pregnancy induced hypertension (PIH). Methods. Blood samples were drawn from 97 pr...Objective. To measure the circulating levels of thrombomodulin (TM) and plasminogen activator inhibitor type- I (PAI- I) in women with pregnancy induced hypertension (PIH). Methods. Blood samples were drawn from 97 pregnant women in their third trimester, grouped as 25 mild PIH,26 moderate PIH,22 severe PIH and 24 normotensive healthy pregnant women for determining levels of TM by ELISA,PAI- I by colorimetric assay methods, and creatinine (Cr) in serum by biochemical method. Results. Circulating levels of TM, PAI- I and TM/Cr ratio increased with increasing severity of PIH. There were no significant differences between mild and normotensive pregnant women. The parameters were significantly changed in the moderate and severe PIH groups. Conclusion. TM and PAI- I may serve as meaningful clinical markers for the assessment of the endothelial damage in PIH, which is very important in evaluating and following the development of PIH.展开更多
Objective To explore the potential mechanism of breakthrough bleeding associated with progestin with in vitro methods.Methods The isolation and culture of human endometrial endothelial cells(HEECs)was performed with t...Objective To explore the potential mechanism of breakthrough bleeding associated with progestin with in vitro methods.Methods The isolation and culture of human endometrial endothelial cells(HEECs)was performed with the method established in our laboratory.The content and activity of urokinase-type plasminogen activator(uPA)and the content of plasminogen activator inhibitor-1(PAI-1)in cell supernatants after incubated with different concentrations of progesterone(0-5 μmol/L)and 17β-estradiol(0,0.1,or 1 nmol/L)were measured by method of ELISA.Apoptosis rate of HEECs was measured by flow cytometry.Viable cell count was measured by MTT.Results The increased level of progesterone(0.5-5 μmol/L)combined with 17β-estradiol elevated content and activity of uPA while the production of PAI-1 remained unchanged.The apoptosis of HEECs was inhibited along with the increment of total viable cell counts at higher concentrations of progesterone with 17β-estradiol.Conclusion The inhibition of apoptosis and increased content and activity of uPA may contribute to the occurrence of irregular bleeding associated with progestin use to some extent.展开更多
Changes of ovarian tPA,uPA and PA inhibitor activities were examined in PMSG-and hCG-treatedimmature mice during periovulatory periods.The results show that 15% of the gonadotropin-treatedanimals ovulated 8 hrs after ...Changes of ovarian tPA,uPA and PA inhibitor activities were examined in PMSG-and hCG-treatedimmature mice during periovulatory periods.The results show that 15% of the gonadotropin-treatedanimals ovulated 8 hrs after hCG administration,about 6-8 hrs earlier than in rat.It is also shownthat not only tPA activity,but also uPA activity,was regulated by gonadotropins in ovarianhomogenates and granulosa cells,and they reached maximum prior to ovulation.No measurableamount of PAI-1 activity could be detected in mouse granulosa cell conditioned medium andfollicular fluid,but considerable amount of α_2-antiplasmin,a specific inhibitor for plasmin,wasfound in follicular fluid.Cumulus-oocyte complexes contain mainly tPA.Since the ovulated eggsstill have high tPA activity,it is thought that the enzyme in the oocyte may play an important rolein implantation.展开更多
In this experiment, expression of tissue-type plasminogen activator (t-PA) in smooth muscle cells (SMCs) was measured at different intervals after the arterial injury. In the normal iliac arteries, only low levels of ...In this experiment, expression of tissue-type plasminogen activator (t-PA) in smooth muscle cells (SMCs) was measured at different intervals after the arterial injury. In the normal iliac arteries, only low levels of t-PA activity were estimated. t-PA activity in extracts of the iliac arteries increased significantlyat the 4th day after the injury, equivalent to the process that SMCs migrated from the media to the intima,and the t-PA activity was then decreased approximately to the normal level at the 7th day. Coexistent to the above data, results from in situ hybridization showed that the expression of t-PA mRNA in the intima as well as media increased also significantly at the 4th day after the arterial injury, and at the 7th day, tPA mRNA was detected only in those SMCs locating closely adjacent to the internal elastic lamina. These results suggest that t-PA might play an important role in SMC migration following endothelial injury, andantagonism of t-PA expression and/or activity within the vessel wall might be helpful in intervening the de velopment of restenosis following angioplasty.展开更多
Objective To study the expression and role of plasminogen system in the process of restenosis. Methods We established a double-injury model of atherosclerotic restenosis in rabbit iliac artery mimicking human arterial...Objective To study the expression and role of plasminogen system in the process of restenosis. Methods We established a double-injury model of atherosclerotic restenosis in rabbit iliac artery mimicking human arterial restenosis. The time course of tissue plaminogen activator (tPA), urokinase plasminogen activator (uPA), urokinase plasminogen activator receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) was investigated by immunohistochemistry. The mRNA expression of uPA and uPAR were detected after vascular procedures by in situ hybridization. Results In uninjured arteries, the weak expression of tPA and PAI-1 was detected in intimal and endothelial cells. The expression of tPA, uPA, uPAR and PAI-1 was significantly induced after double-injury, but after double-injury 14d, the expression of tPA restore to preinjury levels. The expression of uPA and uPAR in intimal was higher than that of media and maintain high levels in intimal within 42d and 56d. Conclusion Whereas t-PA is primarily involved in clot dissolution and play a limited role in the process of restenosis, in plasminogen system, uPA and uPAR play a prominent role in the process of restenosis.展开更多
文摘AIM: To investigate the changes in plasminogen activity level during mesenteric ischemia. METHODS: We performed laparotomy in 90 female Wistar-Albino rats (average weight 230 g). In sham groups (SL) (GroupsⅠand Ⅱ) the superior mesenteric artery (SMA) and vein (SMV) were explored, but not tied. In SMA groups (Groups Ⅲ and Ⅳ) the SMA was ligated, and in SMV groups (Groups Ⅴ and Ⅵ) the SMV was ligated. On re-laparatomy 2 mL of blood was drawn at 1 h in groupsⅠ, Ⅲ and Ⅴ, and at 3 h in groups Ⅱ, Ⅳ and Ⅵ. Plasminogen levels were assessed and comparisons were made between groups and within each group. RESULTS: The mean plasminogen activity in the SL group was significantly higher than SMA (25.1 ± 10.8 vs 11.8 ± 4.6, P < 0.001) or SMV (25.1 ± 10.8 vs 13.7 ± 4.4, P < 0.001) groups both at 1 h and at 3 h (29.8 ± 8.9 vs 15.1 ± 5.7, P < 0.0001; 29.8 ± 8.9 vs 14.2 ± 2.9, P < 0.0001). There were no significant differences between the values of SMA and SMV groups at 1 h (P = 0.28) and at 3 h (P = 0.71). In each group, plasminogen activity levels did not change significantly between the two measurements performed at 1 h and 3 h. CONCLUSION: We conclude that blood plasminogen activities decrease during early phases of both arterial and venous mesenteric ischemia which may be a useful marker for early diagnosis.
文摘Objective. To measure the circulating levels of thrombomodulin (TM) and plasminogen activator inhibitor type- I (PAI- I) in women with pregnancy induced hypertension (PIH). Methods. Blood samples were drawn from 97 pregnant women in their third trimester, grouped as 25 mild PIH,26 moderate PIH,22 severe PIH and 24 normotensive healthy pregnant women for determining levels of TM by ELISA,PAI- I by colorimetric assay methods, and creatinine (Cr) in serum by biochemical method. Results. Circulating levels of TM, PAI- I and TM/Cr ratio increased with increasing severity of PIH. There were no significant differences between mild and normotensive pregnant women. The parameters were significantly changed in the moderate and severe PIH groups. Conclusion. TM and PAI- I may serve as meaningful clinical markers for the assessment of the endothelial damage in PIH, which is very important in evaluating and following the development of PIH.
文摘Objective To explore the potential mechanism of breakthrough bleeding associated with progestin with in vitro methods.Methods The isolation and culture of human endometrial endothelial cells(HEECs)was performed with the method established in our laboratory.The content and activity of urokinase-type plasminogen activator(uPA)and the content of plasminogen activator inhibitor-1(PAI-1)in cell supernatants after incubated with different concentrations of progesterone(0-5 μmol/L)and 17β-estradiol(0,0.1,or 1 nmol/L)were measured by method of ELISA.Apoptosis rate of HEECs was measured by flow cytometry.Viable cell count was measured by MTT.Results The increased level of progesterone(0.5-5 μmol/L)combined with 17β-estradiol elevated content and activity of uPA while the production of PAI-1 remained unchanged.The apoptosis of HEECs was inhibited along with the increment of total viable cell counts at higher concentrations of progesterone with 17β-estradiol.Conclusion The inhibition of apoptosis and increased content and activity of uPA may contribute to the occurrence of irregular bleeding associated with progestin use to some extent.
基金This work was supported by National Natural Science Foundation,the"Eighth Five"Scientific Development Program,research fund for State Key Laboratories and Rockefeller Foundation,New York,USA.
文摘Changes of ovarian tPA,uPA and PA inhibitor activities were examined in PMSG-and hCG-treatedimmature mice during periovulatory periods.The results show that 15% of the gonadotropin-treatedanimals ovulated 8 hrs after hCG administration,about 6-8 hrs earlier than in rat.It is also shownthat not only tPA activity,but also uPA activity,was regulated by gonadotropins in ovarianhomogenates and granulosa cells,and they reached maximum prior to ovulation.No measurableamount of PAI-1 activity could be detected in mouse granulosa cell conditioned medium andfollicular fluid,but considerable amount of α_2-antiplasmin,a specific inhibitor for plasmin,wasfound in follicular fluid.Cumulus-oocyte complexes contain mainly tPA.Since the ovulated eggsstill have high tPA activity,it is thought that the enzyme in the oocyte may play an important rolein implantation.
文摘In this experiment, expression of tissue-type plasminogen activator (t-PA) in smooth muscle cells (SMCs) was measured at different intervals after the arterial injury. In the normal iliac arteries, only low levels of t-PA activity were estimated. t-PA activity in extracts of the iliac arteries increased significantlyat the 4th day after the injury, equivalent to the process that SMCs migrated from the media to the intima,and the t-PA activity was then decreased approximately to the normal level at the 7th day. Coexistent to the above data, results from in situ hybridization showed that the expression of t-PA mRNA in the intima as well as media increased also significantly at the 4th day after the arterial injury, and at the 7th day, tPA mRNA was detected only in those SMCs locating closely adjacent to the internal elastic lamina. These results suggest that t-PA might play an important role in SMC migration following endothelial injury, andantagonism of t-PA expression and/or activity within the vessel wall might be helpful in intervening the de velopment of restenosis following angioplasty.
文摘Objective To study the expression and role of plasminogen system in the process of restenosis. Methods We established a double-injury model of atherosclerotic restenosis in rabbit iliac artery mimicking human arterial restenosis. The time course of tissue plaminogen activator (tPA), urokinase plasminogen activator (uPA), urokinase plasminogen activator receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) was investigated by immunohistochemistry. The mRNA expression of uPA and uPAR were detected after vascular procedures by in situ hybridization. Results In uninjured arteries, the weak expression of tPA and PAI-1 was detected in intimal and endothelial cells. The expression of tPA, uPA, uPAR and PAI-1 was significantly induced after double-injury, but after double-injury 14d, the expression of tPA restore to preinjury levels. The expression of uPA and uPAR in intimal was higher than that of media and maintain high levels in intimal within 42d and 56d. Conclusion Whereas t-PA is primarily involved in clot dissolution and play a limited role in the process of restenosis, in plasminogen system, uPA and uPAR play a prominent role in the process of restenosis.
