Department

Biomedical and General Engineering Department

Degree Name

BS in Biomedical Engineering

Date

6-2014

Advisor(s)

Trevor Cardinal

Abstract/Summary

Peripheral arterial occlusive disease (PAOD) occurs due to the build up of atherosclerotic plaque and reduces blood flow to cause chronic ischemia. Patients with PAOD may experience intermittent claudication, or the pain in limb skeletal muscles due to a decease in blood flow. Collateral arteries can act as a natural bypass and improve blood flow to hypoxic tissue by creating an alternate route for blood to flow, but not all patients with PAOD have pre-existing collateral networks. Animal studies indicate that tissues without pre-existing collateral networks can form de novo collaterals from capillaries following occlusion of a feed artery. Unfortunately, theses de novo collaterals, termed arterialized collateral capillaries (ACCs) lack functional vasodilation at day-7 following feed artery occlusion. To induce the formation of ACCs, we ligated the lateral feed artery in the spinotrapzeius muscle in Balb/c mice. We evaluated the potential mechanism of impaired functional vasodilation in immature arterialized collateral capillaries (7 days following occlusion) by measuring endothelial-dependent vasodilation to bradykinin and endothelial-independent vasodilation to isoproterenol and sodium nitroprusside. Vasodilation to both the endothelial-dependent and endothelial-independent vasodilators was impaired in the immature ACCs as compared to the terminal arterioles on the unoperated sham side. Similar responses to the endothelial cell and smooth muscle cell-dependent vasodilations suggest that impaired functional vasodialtion is due to impaired vascular smooth muscle cell function, which is consistent with our preivous research. We speculate that the SMCs of the ACCs are immature and may still be remodeling, rearranging, or modulating phenotype in the newly formed collaterals. Determining factors to induce mature arterialized collateral capillaries in patients with PAOD lacking pre-existing collateral netoworks could reduce ischemia and improve prognosis.

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