McLean House, Class of 2015
NIDDK Medical Student Research Training Program
Molecular Physiology and Biophysics, Vanderbilt School of Medicine, Owen P. McGuinness, Ph.D
Time spent: 35-50 hours/week, for 1 year
I had the opportunity to study glucose homeostasis in critically-ill patients from a basic science perspective. Using conscious, catheterized mice we perform hyperinsulinemic-euglycemic clamps to measure insulin action during experimental endotoxemia. We tested the hypothesis that excess nitric oxide generation impairs glucose uptake in skeletal muscle through a deficit of substrate delivery and tissue perfusion.
We analyze protein content and gene expression in a variety of tissues to determine changes in insulin signaling, cytokine expression, and endothelin-1 regulation. Using tracer methods, we determined tissue-specific glucose uptake, whole body glucose turnover, and hepatic glucose production. We found that hypotension alone causes insulin resistance. Furthermore, mice who do not express inducible nitric oxide synthase are partially protected from endotoxin-mediated impairments in glucose uptake.
Working in a metabolism laboratory has enhanced my knowledge of critical pathways and underscored the importance of how the body handles metabolites under stress.