Platelet activation during angiotensin II infusion in healthy volunteers.
The present study was undertaken to evaluate the effects of an intravenous infusion of angiotensin II (10 ng/kg per min) on platelet function and coagulation in vivo in 18 healthy males. The infusion increased mean arterial pressure by 23+/-2 mm Hg. Plasma beta-thromboglobulin levels, reflecting platelet secretion, increased by 66+/-24% during the infusion, as did also platelet surface expression of P-selectin as measured by flow cytometry. Platelet fibrinogen binding increased, whereas platelet aggregability, assessed by ex vivo filtragometry, was unaltered. Angiotensin II caused mild activation of the coagulation cascade with increases in plasma levels of thrombin-antithrombin complex and prothrombin fragment F1 + 2. In conclusion, angiotensin II has mild platelet-activating effects in vivo and also enhances coagulation. Markers of platelet secretion are significantly increased, whereas markers of platelet aggregability are less affected. The clinical relevance of these findings remains to be clarified.
Larsson
P T
PT
Department of Clinical Physiology, Karolinska Institutet, Södersjukhuset, Stockholm, Sweden. thomas.larsson@fys.sos.sll.se
Schwieler
J H
JH
Wallén
N H
NH
D000328:Adult; D000804:Angiotensin II / Q000008:administration & dosage* / Q000494:pharmacology; D000990:Antithrombin III / Q000032:analysis; D001772:Blood Cell Count / Q000187:drug effects; D001777:Blood Coagulation / Q000187:drug effects; D001792:Blood Platelets / Q000737:chemistry / Q000166:cytology / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002395:Catecholamines / Q000097:blood; D004305:Dose-Response Relationship, Drug; D005069:Evaluation Studies as Topic; D005434:Flow Cytometry; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000032:analysis; D010446:Peptide Fragments / Q000187:drug effects / Q000378:metabolism; D010447:Peptide Hydrolases / Q000032:analysis; D015539:Platelet Activation / Q000187:drug effects*; D010974:Platelet Aggregation / Q000187:drug effects; D011498:Protein Precursors / Q000187:drug effects / Q000378:metabolism; D011516:Prothrombin / Q000187:drug effects / Q000378:metabolism; D013917:Thrombin / Q000096:biosynthesis; D001620:beta-Thromboglobulin / Q000187:drug effects; D014841:von Willebrand Factor / Q000187:drug effects
D002395:Catecholamines; D019007:P-Selectin; D010446:Peptide Fragments; D011498:Protein Precursors; C046193:antithrombin III-protease complex; D001620:beta-Thromboglobulin; D014841:von Willebrand Factor; D000804:Angiotensin II; C029733:prothrombin fragment 1; C044183:prothrombin fragment 2; D000990:Antithrombin III; D011516:Prothrombin; D010447:Peptide Hydrolases; D013917:Thrombin