Decreased fibrinolytic activity and increased platelet function in hypertension. Possible influence of calcium antagonism.
Twelve patients with mild hypertension were compared, after 14 days of placebo, with an age- and gender-matched group of 12 healthy volunteers for platelet aggregability and fibrinolytic activity. Following this, 10 of the 12 hypertensives were treated with the calcium antagonist isradipine for 12 months. Blood was drawn for determinations of platelet aggregation and fibrinolytic activity after two weeks and 12 months of treatment. Platelet aggregation tended to increase in the hypertensives compared with controls, indicated by a lowering of the adenosine diphosphate (ADP) threshold value for irreversible aggregation. Tissue-plasminogen activator (t-PA) activity was significantly decreased in hypertensives compared to controls (P less than .05). During therapy, platelet aggregation decreased and t-PA activity increased (P less than .05). The present data suggest that fibrinolytic activity is decreased and platelet aggregation increased in mild hypertension. Besides the blood pressure-lowering effect, isradipine may protect against thromboembolic diseases by modifying platelet function and fibrinolytic activity.
Gleerup
G
G
Medical Department B, Frederiksberg Hospital, Copenhagen.
Winther
K
K
D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000187:drug effects* / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology* / Q000627:therapeutic use; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects*; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy* / Q000503:physiopathology; D017275:Isradipine; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D011725:Pyridines / Q000494:pharmacology / Q000627:therapeutic use; D010959:Tissue Plasminogen Activator / Q000378:metabolism
D002121:Calcium Channel Blockers; D010975:Platelet Aggregation Inhibitors; D011725:Pyridines; D010959:Tissue Plasminogen Activator; D017275:Isradipine