Analysis of factors influencing the blood levels and activities of tissue‐type plasminogen activator (t‐PA)

Abstract

This study aimed to correlate plasmatic tissue‐type plasminogen activator (t‐PA) levels and activity with parameters of artery blood flow and vessel walls, nail fold microcirculation, hemorheology, serum glucose, and lipids. Thirty healthy volunteers (female/male 12/18) aged 40–60 (average 46) were included in the study. In citrate venous blood, the following parameters were determined: carotid mean velocity, carotid intimal‐medial‐thickness (IMT), capillary circulation parameters, hemorheology index, serum glucose, and lipids. Analysis of data showed that t‐PA concentration was positively and significantly correlated with total cholesterol, triglycerides, and serum glucose (P<0.05, P<0.05, and P<0.01), but t‐PA activity showed no correlation with them; among the hemorheology factors investigated, t‐PA concentration showed the strongest positive correlation with both whole blood viscosity and reduced blood viscosity at high and low shear rate separately (P<0.01), t‐PA activity showed no correlation with any hemorheology factors; t‐PA concentration showed no correlation with any investigated nail fold capillary parameters, whereas t‐PA activity was significantly and negatively associated with capillary loop number (P<0.05); t‐PA concentration and activity was not associated with values of carotid maximum intimal‐medial‐thickness (mIMT) and mean velocity or systolic, diastolic blood pressure (P>0.05). But subjects with mIMT 1.0 mm showed higher t‐PA levels compared with those with mIMT < 1.0 mm (P<0.05) and decreased carotid mean velocity (P<0.01). These findings suggest that multiple vascular disease risk factors would influence the t‐PA level; t‐PA concentration does not parallelize with t‐PA activity.