Relationship between brachial and femoral artery endothelial vasomotor function/phenotype in pigs

Abstract

In humans, the measurement of brachial artery endothelial vasomotor function is used as a surrogate index of systemic endothelial health; however, the applicability of brachial artery findings to other vasculatures needs to be examined. The purpose of the present investigation was to test the following hypotheses: (1) brachial and femoral artery endothelium-dependent/independent relaxation is correlated; (2) endothelial expression of pro-/antiatherogenic proteins is correlated between brachial and femoral arteries; and (3) within vessel, there is a positive correlation between expression of antiatherogenic proteins and endothelium-dependent/independent relaxation, and an inverse correlation between expression of proatherogenic proteins and relaxation. In vitro endothelium-dependent (bradykinin [BK] and acetylcholine [Ach]) and -independent (sodium nitroprusside [SNP]) relaxation were evaluated in harvested brachial and femoral arteries of 96 Yucatan miniature swine. In a subset of pigs (n = 32), expression of 18 pro-/antiatherogenic proteins was measured from brachial and femoral artery endothelial cell scrapes using immunoblot analysis. Vascular sensitivity (half-maximal effective dose) to BK, Ach and SNP was highly correlated between brachial and femoral arteries (P < 0.01). A significant correlation was found between brachial and femoral arteries for content of six of the 18 measured proteins (P < 0.01). Furthermore, expression of two proteins (eNOS and COX-1) was correlated with vasorelaxation function in the brachial artery (P < 0.01). We provide the first evidence of a relationship between brachial and femoral artery endothelium-dependent relaxation. Our data also suggest that, in general terms, endothelial expression of several established pro-/antiatherogenic proteins is not robustly associated between brachial and femoral arteries, and does not link strongly to vasorelaxation function.