Effects Of 10-days Bed-rest On Nitric Oxide Metabolites And Microvascular Function Assessed By Near-infrared Spectroscopy: 2819 Board# 280 May 29 10: 30 AM-12: 00 PM

PURPOSE: Prolonged periods of bed-rest (BR), experimental simulation of microgravity, greatly affect oxidative metabolism by acting at several levels of the O 2 pathway. Short duration (10 days) of horizontal BR negatively affects in-vivo functional biomarkers related to skeletal muscle oxidative metabolism without affecting mitochondrial respiration ex-vivo. The impairment of muscle oxidative metabolism can partially derive from reduced O 2 delivery, altered peripheral O 2 diffusion and a mismatch between O 2 delivery and O 2 consumption, likely related to an altered nitric oxide signaling. Aim of this study was to evaluate the effects of 10 days of BR on microvascular reactivity indexes determined at skeletal muscle level by near infrared spectroscopy and nitric oxide metabolites.