OCR Text |
Show 35 college of health Aging has been documented to reduce skeletal muscle blood flow. Increased local temperature due to me-tabolism is likely a mechanism contributing to functional sympatholysis. It is currently unknown whether aging impacts this response and if vascular function is a mediating factor. Therefore, we utilized an in vitro approach to determine if basal vascular function or the effect of temperature was different across age (<50, 50-65, >65yrs) or gender. METHODS: Human vessels (~500μM) supplying skeletal muscle were obtained during pre-scheduled surgeries (15 males, 11 females; 56 ± 15 yrs). Vessels were dissected into four 2-mm rings and mounted on a wire myograph. All vessels underwent a stepwise length tension procedure to determine LMAX (≤10% increase in vasocontraction in response to 100mM KCl). Vessel function was char-acterized using potassium chloride (KCl), phenylephrine (PE), acetylcholine (Ach), and sodium nitroprus-side (SNP) dose response curves to determine non-receptor and receptor mediated vasocontraction and vasorelaxation. To determine if temperature exerts a sympatholytic effect, PE (1mM) was given at 37°C and 39°C. Data are presented as mean±SE. RESULTS: Temperature reduced α1-mediated vasocontraction (37°C 76±17 vs 39°C 46±8 percent contraction; p< 0.05), however, this response was not influenced by age or gender. Although the absolute maximal PE-induced tension varied largely by gender (p< 0.05), the percent increases in PE-induced tension were similar. CONCLUSION: There seems to be no baseline differences in vascular function with regards to age or gender. Increasing temperature could be a contributing factor to functional sympatholysis, but gender and age appear not to influence this process. TEMPERATURE-INDUCED SYMPATHOLYSIS AND VASCULAR FUNCTION: THE ROLE OF ADVANCING AGE AND GENDER Cheyenne Schmid (Russell Richardson) Department of Exercise and Sport Science University of Utah UNDERGRADUATE RESEARCH ABSTRACTS Russell Richardson Cheyenne Schmid |