Vasodilation of lower leg arterioles is impaired in animal models of chronic peripheral ischemia. In addition to arterioles, feed arteries are a critical component of the vascular resistance network, accounting for as much as 50% of the pressure drop across the arterial circulation. Despite the critical importance of feed arteries in blood flow control, the impact of ischemia on feed artery vascular reactivity is unknown. At 14 days following unilateral resection of the femoral–saphenous artery–vein pair, functional vasodilation of the profunda femoris artery was severely impaired, 11 ± 9 versus 152 ± 22%. Although endothelial and smooth muscle-dependent vasodilation were both impaired in ischemic arteries compared to control arteries (Ach: 40 ± 14 versus 81 ± 11%, SNP: 43 ± 12 versus and 85 ± 11%), the responses to acetylcholine and sodium nitroprusside were similar, implicating impaired smooth muscle-dependent vasodilation. Conversely, vasoconstriction responses to norepinephrine were not different between ischemic and control arteries, −68 ± 3 versus −66 ± 3%, indicating that smooth muscle cells were functional following the ischemic insult. Finally, maximal dilation responses to acetylcholine, ex vivo, were significantly impaired in the ischemic artery compared to control, 71 ± 9 versus 97 ± 2%, despite a similar generation of myogenic tone to the same intravascular pressure (80 mmHg). These data indicate that ischemia impairs feed artery vasodilation by impairing the responsiveness of the vascular wall to vasodilating stimuli. Future studies to examine the mechanistic basis for the impact of ischemia on vascular reactivity or treatment strategies to improve vascular reactivity following ischemia could provide the foundation for an alternative therapeutic paradigm for peripheral arterial occlusive disease.
Keywords: vasodilation, reactivity, chronic ischemia, hindlimb, mouse
Citation: Cardinal TR, Struthers KR, Kesler TJ, Yocum MD, Kurjiaka DT and Hoying JB (2011) Chronic hindlimb ischemia impairs functional vasodilation and vascular reactivity in mouse feed arteries. Front. Physio. 2:91. doi: 10.3389/fphys.2011.00091
Received: 03 September 2011; Accepted: 14 November 2011;
Published online: 06 December 2011.
Edited by:John D. Imig, Medical College of Wisconsin, USA
Reviewed by:R. Dan Rudic, Medical College of Georgia, USA
Copyright: © 2011 Cardinal, Struthers, Kesler, Yocum, Kurjiaka and Hoying. This is an open-access article distributed under the terms of the Creative Commons Attribution Non Commercial License, which permits non-commercial use, distribution, and reproduction in other forums, provided the original authors and source are credited.
*Correspondence: Trevor R. Cardinal, Biomedical Engineering, California Polytechnic State University, 1 Grand Avenue, San Luis Obispo, CA 93407-0365, USA. e-mail: firstname.lastname@example.org
†Present address: David T. Kurjiaka, Biomedical Sciences Department, Grand Valley State University, Allendale, MI, USA; James B. Hoying, Cardiovascular Therapeutics, Cardiovascular Innovation Institute, Louisville, KY, USA