Influence of oral contraceptive use on endothelial t-PA release in healthy premenopausal women.
We determined the influence of oral contraceptives (OC) on the capacity of the endothelium to release tissue-type plasminogen activator (t-PA). Twenty-three healthy premenopausal women were studied: 12 nonusers and 11 users of OC. Net endothelial release rates of t-PA were calculated as the product of the arteriovenous concentration gradient and forearm plasma flow in response to intra-arterial bradykinin (BK: 12.5-50 ng. 100 ml tissue(-1) x min(-1)) and sodium nitroprusside (SNP: 1.0-4.0 microg x 100 ml tissue(-1) x min(-1)). Net release of t-PA antigen and increment in t-PA activity across the forearm to BK increased (P < 0.01) in a dose-dependent fashion and to similar extents in the nonusers and users of OC. At the highest BK dose, net release of t-PA antigen was 64.5 +/- 8.2 and 66.2 +/- 15.4 ng x 100 ml tissue(-1) x min(-1) in the nonusers and users of OC, whereas the net increment in t-PA activity was 18.6 +/- 3.0 and 16.0 +/- 2.0 IU. 100 ml tissue(-1) x min(-1), respectively. There was no effect of SNP on t-PA release in either group. These results indicate that endothelial t-PA release is not altered in premenopausal women who use oral contraception.
Hoetzer
Greta L
GL
Integrative Vascular Biology Laboratory, Department of Kinesiology and Applied Physiology, University of Colorado, Boulder 80309, USA.
Stauffer
Brian L
BL
Greiner
Jared J
JJ
Casas
Yoli
Y
Smith
Derek T
DT
DeSouza
Christopher A
CA
D000328:Adult; D001920:Bradykinin / Q000494:pharmacology; D003276:Contraceptives, Oral / Q000009:adverse effects*; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000378:metabolism*; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects; D005542:Forearm / Q000098:blood supply; D006801:Humans; D009599:Nitroprusside / Q000494:pharmacology; D017395:Plasminogen Activator Inhibitor 1 / Q000097:blood / Q000378:metabolism; D017697:Premenopause; D010959:Tissue Plasminogen Activator / Q000097:blood / Q000378:metabolism*; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
D003276:Contraceptives, Oral; D017395:Plasminogen Activator Inhibitor 1; D014665:Vasodilator Agents; D009599:Nitroprusside; D010959:Tissue Plasminogen Activator; D001920:Bradykinin