HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 551/2/721    most recent jphysiol.2003.044107v1 Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Hoetzer, G. L. Articles by DeSouza, C. A. Search for Related Content PubMed PubMed Citation Articles by Hoetzer, G. L. Articles by DeSouza, C. A.

Acute and chronic effects of oestrogen on endothelial tissue-type plasminogen activator release in postmenopausal women

Greta L. Hoetzer *, Brian L. Stauffer *†, Heather M. Irmiger *, Marilyn Ng *, Derek T. Smith * and Christopher A. DeSouza *‡

The capacity of vascular endothelium to locally release tissue-type plasminogen activator (t-PA) represents an important endogenous defence mechanism against intravascular fibrin deposition and thrombosis. We determined the influence of chronic and acute oestrogen administration on endothelial t-PA release in postmenopausal women. Sixty-three healthy postmenopausal women were studied: 31 non-users (age 58 ± 1 years) and 32 users of hormone replacement therapy, including oestrogen alone (ORT: 62 ± 2 years; n = 15) and in combination with progesterone (HRT: 57 ± 1 years; n = 17). Net endothelial t-PA release was determined in vivo, in response to intrabrachial infusions of bradykinin and sodium nitroprusside. To examine the acute effects of oestrogen on endothelial t-PA release, bradykinin and sodium nitroprusside dose-response curves were repeated in the presence of 17 -oestradiol in 20 of the 31 non-users. Net endothelial release of t-PA was ~30 % higher (P < 0.01) in women taking ORT (from 2.0 ± 1.0 to 83.6 ± 9.2 ng (100 ml tissue)^-1 min^-1) compared with those taking HRT (from 1.4 ± 0.4 to 63.5 ± 5.6 ng (100 ml tissue)^-1 min^-1) and those not taking supplementation (1.0 ± 0.7 to 63.0 ± 4.7 ng (100 ml tissue)^-1 min^-1). Intra-arterial infusion of 17 -oestradiol significantly potentiated bradykinin-induced t-PA release. Net endothelial release of t-PA was ~45 % higher (P < 0.01) after (from 1.0 ± 0.8 to 87.4 ± 9.9 ng (100 ml tissue)^-1 min^-1) versus before (1.2 ± 0.6 to 60.8 ± 5.6 ng (100 ml tissue)^-1 min^-1) acute 17 -oestradiol administration. Our results suggest that oestrogen has a direct modulatory effect on the capacity of the endothelium to release t-PA in healthy postmenopausal women. However, progesterone appears to oppose the favourable influence of oestrogen on endothelial fibrinolytic capacity.

This article has been cited by other articles:

				D. R. Seals, C. A. DeSouza, A. J. Donato, and H. Tanaka Habitual exercise and arterial aging J Appl Physiol, October 1, 2008; 105(4): 1323 - 1332. [Abstract] [Full Text] [PDF]

				M. Pretorius, G. P. van Guilder, R. J. Guzman, J. M. Luther, and N. J. Brown 17{beta}-Estradiol Increases Basal but Not Bradykinin-Stimulated Release of Active t-PA in Young Postmenopausal Women Hypertension, April 1, 2008; 51(4): 1190 - 1196. [Abstract] [Full Text] [PDF]

				G. P. Van Guilder, M. Pretorius, J. M. Luther, J. B. Byrd, K. Hill, J. V. Gainer, and N. J. Brown Bradykinin Type 2 Receptor BE1 Genotype Influences Bradykinin-Dependent Vasodilation During Angiotensin-Converting Enzyme Inhibition Hypertension, February 1, 2008; 51(2): 454 - 459. [Abstract] [Full Text] [PDF]

				J. J. Oliver, D. J. Webb, and D. E. Newby Stimulated Tissue Plasminogen Activator Release as a Marker of Endothelial Function in Humans Arterioscler. Thromb. Vasc. Biol., December 1, 2005; 25(12): 2470 - 2479. [Abstract] [Full Text] [PDF]

				M. Pretorius, J. M. Luther, L. J. Murphey, D. E. Vaughan, and N. J. Brown Angiotensin-Converting Enzyme Inhibition Increases Basal Vascular Tissue Plasminogen Activator Release in Women But Not in Men Arterioscler. Thromb. Vasc. Biol., November 1, 2005; 25(11): 2435 - 2440. [Abstract] [Full Text] [PDF]

				G. P. Van Guilder, G. L. Hoetzer, D. T. Smith, H. M. Irmiger, J. J. Greiner, B. L. Stauffer, and C. A. DeSouza Endothelial t-PA release is impaired in overweight and obese adults but can be improved with regular aerobic exercise Am J Physiol Endocrinol Metab, November 1, 2005; 289(5): E807 - E813. [Abstract] [Full Text] [PDF]