Summary
The effects of the selective alpha-1-adrenoceptor antagonist doxazosin on metabolic
and fibrinolytic parameters were studied in hypertensive patients with various degrees
of fasting plasma insulin levels (Group A: 22.5 ± 3 μU/ml, Group B: 8.1 ± 1.5 μU/ml;
p <0.01) to disclose a potential link between a doxazosin-induced alteration of insulin
and/or lipid metabolism and possible changes of these parameters on the fibrinolytic
system. Doxazosin treatment resulted in a dose-dependent reduction of basal insulin
levels in group A to 16 ± 3 μU/ml; p <0.05. This finding was paralleled by a dose-dependent
increase in t-PAmass concentration in the same patient group (basal t-PAmass from 9.7 ± 1 to 15.5 ± 2 ng/ml; p <0.05). As PAI-1 “active” as well as total antigen
levels were not altered in parallel, the net effect on the endogenous fibrinolytic
system is an increase of the fibrinolytic potential.