[Efffect of plasminogen activator inhibitor-1 and endothelin-1 on the atherosclerosis in the maintenance hemodialysis patients].

OBJECTIVE

To investigate the effect of plasminogen activator inhibitor-1 (PAI-1), tissue type plasminogen activator (t-PA), and endothelin-1 (ET-1) on the atherosclerosis progress in the maintenance hemodialysis patients.

METHODS

We enrolled 19 patients with maintenance hemodialysis (MHD) and 11 healthy people as control. Patients were divided into 2 groups according to their age above or below 40 years old (11 and 8 in each, respectively), whereas the subjects in control group were below 40 years old. All the clinical information of the research subjects was collected: including age, gender, time of hemodialysis, blood pressure, blood urea nitrogen (BUN), and serum creatinine (SCr). Immunohistochemistry and pathological image analysis were used to investigate the pathological changes, calcification and the expression of PAI-1, t-PA, and ET-1 on the blood vessel.

RESULTS

Compared with the age-matched healthy control group, there were higher blood vascular media thickness, blood vascular media thickness/diagmeter ratio, blood vascular media thickness area/vascular inter-wall area ratio (P<0.05) and more calcification (P<0.05) in the the internal iliac artery in the chronic renal failure MHD patients. All the results were similar when compared the above 40 years old group with the below 40 years old one in the chronic renal failure MHD patients. There were positive correlation of blood vascular media thickness with age and blood pressure (P<0.05). Expression of PAI-1, ET-1, t-PA on the internal iliac artery vessel was elevated in the chronic renal failure MHD patients compared with the health control (P<0.05). The level of PAI-1 or ET-1 was much higher in the above 40 years old group than the below 40 years old one in the chronic renal failure MHD patients, whereas there was no significant difference in the t-PA expression between the 2 groups (P<0.05). There were positive correlation of PAI-1 or ET-1 expression with age and blood pressure (P<0.05). There were positive correlation of PAI-1 or ET-1 expression with blood vascular media thickness and calcification (P<0.05 or P<0.01). There was no correlation of hemodialysis time with blood vascular media thickness, calcification, PAI-1, t-PA, or ET-1 expressions.

CONCLUSION

MHD patients accompany with atherosclerosis which is severer in the patients above 40 years old than the patients below 40 years old. The higher of the blood pressure, the severer of the atherosclerosis. Abnormal expression of PAI-1 plays an important role in the progress of the atherosclerosis in the chronic renal failure MHD patients, whereas t-PA has no function in this process. The level of PAI-1 and ET-1 would be helpful to evaluating the degree of atherosclerosis in the chronic renal failure MHD patients. Hemodialysis time may not be a potential accelerator for atherosclerosis progression.