Ethnicity affects vasodilation, but not endothelial tissue plasminogen activator release, in response to bradykinin

David A. Rosenbaum, Mias Pretorius, James V. Gainer, Daniel Byrne, Laine J. Murphey, Corrie A. Painter, Douglas E. Vaughan, Nancy J. Brown*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

36 Scopus citations

Abstract

Previous studies indicate that the vasodilator response to bradykinin (BK) and other endothelium-dependent and -independent agonists is decreased in black Americans compared with white Americans. The purpose of the present study was to determine the effect of ethnicity on fibrinolytic function in humans. Graded doses of BK (100, 200, and 400 ng/min), acetylcholine (15, 30, and 60 μg/min; N = 20), or methacholine (3.2, 6.4, 12.8 μg/min; N = 20), and sodium nitroprusside (0.8, 1.6, and 3.2 μg/min) were infused via brachial artery in 19 white and 21 black age-matched normotensive subjects. Forearm blood flow (FBF) was measured by plethysmography, and venous and arterial samples were collected for tissue plasminogen activator (tPA) antigen. Compared with whites (increase in FBF from 3.7±0.5 to 23.9±2.5 mL · min-1 · 100 mL-1), blacks (increase in FBF from 2.8±0.3 to 15.2±1.9 mL · 100 mL-1 · min-1) exhibited a blunted FBF response to BK (P=0.035). Responses to sodium nitroprusside and methacholine or acetylcholine were similarly decreased. In contrast, there was no effect of ethnicity on net tPA antigen release in response to BK (increase from -0.2±0.4 to 67.3±15.2 ng · min-1 · 100 mL-1 in blacks; from 0.04±0.9 to 65.9±13.6 ng · min-1 · min-1 100 mL-1 in whites). Thus, ethnicity significantly influenced the relationship between the flow and tPA release responses to BK (P=0.037). These data suggest that the BK-dependent alterations in vascular fibrinolytic function are preserved in black Americans compared with white Americans.

Original languageEnglish (US)
Pages (from-to)1023-1028
Number of pages6
JournalArteriosclerosis, thrombosis, and vascular biology
Volume22
Issue number6
DOIs
StatePublished - 2002

Keywords

  • Bradykinin
  • Endothelium
  • Ethnicity
  • Fibrinolysis
  • Vasodilator

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine

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