Faculty

Martin Kushmerick
Professor (Radiology)
M.D. University of Pennsylvania, 1963
Ph.D. Molecular Biology, University of Pennsylvania, 1966
Office phone: (206) 543-3762
kushmeri@u.washington.edu

Community of Science page

 

MUSCLE CONTRACTION AND METABOLISM

Our questions focus on energetics of cells and organs, with special attention to muscle. Our primary tools use magnetic resonance spectroscopy and imaging with which a wide variety of biophysical, biochemical and physiological methods are integrated. The overall theme is the signaling, regulation and interaction of molecular and cellular mechanisms in metabolism to sustain and restore energy balance in muscle. Regulation of mitochondrial oxidative phosphorylation and of creatine kinase activity in transient and steady-state perturbations of chemical and mechanical power are major topics. Does creatine kinase have a function beyond spatial and temporal buffering of ATP chemical potential in the cell? What are the cytoplasmic signals informing the mitochondria that some of the chemical potential in ATP has been altered by actomyosin activity? What are the kinetics of those processes? Are they the same in different muscle cell types? Is the regulation similar or different when the tissue adapts, as muscle readily does with a change in usage pattern? What are the signal molecules for changes in phenotype?

Our studies cover the range of organization from single isolated animal muscles to intact human limb muscle. Hence we are reductionists as well as systems physiologists. Part of the work entails constructing mathematical descriptions of each component and solving the system to compare with actual physiological performance measures. We often collaborate with faculty in Bioengineering, Biochemistry and Radiology so the learning environment for students and fellows can be broadly interdisciplinary. A part of our effort is directed to the study of human muscle function, and there are also opportunities to advance our understanding of the pathogenesis of selected disease processes while testing basic mechanisms.