Vascular rarefaction in peripheral skeletal muscle after experimental heart failure.
A decrease in vascular density in peripheral skeletal muscle has been associated with exercise intolerance in humans with congestive heart failure (CHF). The purpose of this study was to determine whether CHF results in a reduction in vascular density in peripheral skeletal muscle. In this established model, CHF was induced by coronary artery ligation in New Zealand White rabbits and sham rabbits that underwent an identical surgical procedure without ligation of the coronary artery. At study termination, rabbits underwent hemodynamic testing and skeletal muscle analysis. The first series of rabbits was divided into sham (n = 6) and CHF (n = 6) 21 days postoperatively. Ten CHF rabbits were then examined 3 (n = 3), 7 (n = 3), and 14 days (n = 4) postoperatively. Vascular density in sham tibialis anterior muscle was 347 +/- 41 capillaries/mm2 or 1.20 +/- 0.11 capillaries/muscle fiber. In 21-day CHF rabbits, the capillary density was significantly lower, 236 +/- 14 capillaries/mm2 or 0.84 +/- 0.04 capillaries/muscle fiber (both P < 0.00001 vs. sham); PECAM protein was 2-fold lower (P < 0.0001) in muscle protein lysates; the fraction of apoptotic cells was greater, 3.8 +/- 2.2 vs. 0.69 +/- 0.56 (P < 0.02 vs. sham) with many TdT-mediated dUTP-biotin nick-end labeling-positive endothelial cells; and Bax protein was 2.8-fold greater (P < 0.0001). By regression analysis, vascular density tended to decrease over time (r2 = 0.572, P < 0.0001). Vascular rarefaction and endothelial apoptosis develop after experimental CHF and may contribute to the skeletal muscle abnormalities in this disease. Modulating vascular density may provide new approaches to treat exercise intolerance in CHF.
Nusz
David J
DJ
Department of Medicine, Durham Veternas Administration and Duke University Medical Center, 508 Fulton St., Durham, NC 277705, USA. annex001@mc.duke.edu
White
David C
DC
Dai
Qunsheng
Q
Pippen
Anne M
AM
Thompson
Michael A
MA
Walton
G Brant
GB
Parsa
Cyrus J
CJ
Koch
Walter J
WJ
Annex
Brian H
BH
D000818:Animals; D017209:Apoptosis; D002196:Capillaries / Q000473:pathology; D003285:Contractile Proteins / Q000378:metabolism; D004730:Endothelium, Vascular / Q000473:pathology; D006333:Heart Failure / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000098:blood supply* / Q000503:physiopathology; D011817:Rabbits; D013997:Time Factors
D003285:Contractile Proteins