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This Article Full Text Full Text (PDF) All Versions of this Article: 297/1/H425    most recent 00689.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map 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 Google Scholar Articles by Donato, A. J. Articles by Seals, D. R. PubMed PubMed Citation Articles by Donato, A. J. Articles by Seals, D. R.

Vascular endothelial dysfunction with aging: endothelin-1 and endothelial nitric oxide synthase

Department of Integrative Physiology, University of Colorado, Boulder, Colorado

Submitted 2 July 2008 ; accepted in final form 19 May 2009

To determine whether impaired endothelium-dependent dilation (EDD) in older adults is associated with changes in the expression of major vasoconstrictor or vasodilator proteins in the vascular endothelium, endothelial cells (EC) were obtained from the brachial artery and peripheral veins of 56 healthy men, aged 18–78 yr. Brachial artery EC endothelin-1 (ET-1) [0.99 ± 0.10 vs. 0.57 ± 0.10 ET-1/human umbilical vein EC (HUVEC) intensity, P = 0.01] and serine 1177 phosphorylated endothelial nitric oxide synthase (PeNOS) (0.77 ± 0.09 vs. 0.44 ± 0.07 PeNOS/HUVEC intensity, P < 0.05) (quantitative immunofluorescence) were greater, and EDD (peak forearm blood flow to intrabrachial acetylcholine) was lower (10.2 ± 0.9 vs. 14.7 ± 1.7 ml·100 ml^–1·min^–1, P < 0.05) in older (n = 18, 62 ± 1 yr) vs. young (n = 15, 21 ± 1 yr) healthy men. EDD was inversely related to expression of ET-1 (r = –0.39, P < 0.05). Brachial artery EC eNOS expression did not differ significantly with age, but tended to be greater in the older men (young: 0.23 ± 0.03 vs. older: 0.33 ± 0.07 eNOS/HUVEC intensity, P = 0.08). In the sample with venous EC collections, EDD (brachial artery flow-mediated dilation) was lower (3.50 ± 0.44 vs. 7.68 ± 0.43%, P < 0.001), EC ET-1 and PeNOS were greater (P < 0.05), and EC eNOS was not different in older (n = 23, 62 ± 1 yr) vs. young (n = 27, 22 ± 1 yr) men. EDD was inversely related to venous EC ET-1 (r = –0.37, P < 0.05). ET-1 receptor A inhibition with BQ-123 restored 60% of the age-related impairment in carotid artery dilation to acetylcholine in B6D2F1 mice (5–7 mo, n = 8; 30 mo, n = 11; P < 0.05). ET-1 expression is increased in vascular EC of healthy older men and is related to reduced EDD, whereas ET-1 receptor A signaling tonically suppresses EDD in old mice. Neither eNOS nor PeNOS is reduced with aging. Changes in ET-1 expression and bioactivity, but not eNOS, contribute to vascular endothelial dysfunction with aging.

endothelium-dependent dilation; brachial artery flow-mediated dilation