EFFECTS OF RADIATION ON CUTANEOUS MICROVASCULAR FUNCTION IN THE INTACT HUMAN CIRCULATION

Abstract

Radiation is a commonly used treatment for various types of cancer, however it is often associated with an increased risk of cardiovascular disease (CVD). Previous animal studies have shown a significant decreased relaxation in irradiated arteries in response to Acetylcholine. However, there is a paucity of knowledge on the effects of radiation within the intact human circulation. Given that changes vascular function occurs early in the progression of numerous cardiovascular and metabolic diseases characterization of the microvascular responses to radiation treatment is critical. Therefore, the primary was to determine the effects of cancer treatment radiation on cutaneous microvascular reactivity in breast cancer patients.METHODSThe present study utilized a longitudinal study design in breast cancer patients receiving radiation therapy. Cutaneous microvascular reactivity to Acetylcholine (ACh) was evaluated following radiation exposure in breast cancer patients at the site of radiation treatment and at a control non‐irradiated site. Briefly, red blood cell flux was measured as an index of cutaneous blood flow via laser Doppler flowmetry with ACh mediated vasodilation determined by iontophoresis drug delivery. Data are expressed as cutaneous vascular conductance.RESULTSTo date, 4 patients have completed the study (planned enrollment of 15 patients). Cutaneous vascular conductance to ACh was significantly attenuated following a total cumulative dose of 1950 ± 719 cGy. Similarly, the total ACh response was decreased in the radiated tissue. The forth coming patients will provide additional insight into the effects of radiation exposure on microvascular reactivity. Furthermore, we will be able to provide insight into the role coexisting risk factors of metabolic syndrome and preexisting atherosclerosis on radiation‐induced vascular dysfunction.CONCLUSIONThis study demonstrates that low doses of radiation for cancer treatment attenuate cutaneous microvascular function, which may have long‐term implications for cardiovascular health in these patients.Support or Funding InformationN/AThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.