R H Fitts

Summary

Affiliation: Marquette University
Country: USA

Publications

  1. ncbi request reprint Physiology of a microgravity environment invited review: microgravity and skeletal muscle
    R H Fitts
    Department of Biology, Marquette University, Milwaukee, WI 53201, USA
    J Appl Physiol (1985) 89:823-39. 2000
  2. ncbi request reprint Spaceflight effects on single skeletal muscle fiber function in the rhesus monkey
    R H Fitts
    Department of Biology, Marquette University, Milwaukee, Wisconsin 53201, USA
    Am J Physiol Regul Integr Comp Physiol 279:R1546-57. 2000
  3. pmc Prolonged space flight-induced alterations in the structure and function of human skeletal muscle fibres
    R H Fitts
    Marquette University, Department of Biological Sciences, PO Box 1881, Milwaukee, WI 53201 1881, USA
    J Physiol 588:3567-92. 2010
  4. ncbi request reprint Functional properties of slow and fast gastrocnemius muscle fibers after a 17-day spaceflight
    J J Widrick
    Department of Biology, Marquette University, Milwaukee 53201, Wisconsin, USA
    J Appl Physiol 90:2203-11. 2001
  5. ncbi request reprint Unilateral lower limb suspension does not mimic bed rest or spaceflight effects on human muscle fiber function
    J J Widrick
    Department of Biology, Marquette University, Milwaukee, Wisconsin 53201, USA
    J Appl Physiol 93:354-60. 2002
  6. ncbi request reprint Functional and structural adaptations of skeletal muscle to microgravity
    R H Fitts
    Department of Biology, Marquette University, Milwaukee, WI 53201, USA
    J Exp Biol 204:3201-8. 2001
  7. ncbi request reprint The deleterious effects of bed rest on human skeletal muscle fibers are exacerbated by hypercortisolemia and ameliorated by dietary supplementation
    R H Fitts
    Dept of Biology, Marquette University, Wehr Life Sciences Bldg, PO Box 1881, Milwaukee, WI 53201 1881, USA
    Am J Physiol Cell Physiol 293:C313-20. 2007
  8. pmc Low cell pH depresses peak power in rat skeletal muscle fibres at both 30 degrees C and 15 degrees C: implications for muscle fatigue
    S T Knuth
    Marquette University, Department of Biological Sciences, PO Box 1881, Milwaukee, WI 53201 1881, USA
    J Physiol 575:887-99. 2006
  9. ncbi request reprint Skeletal muscle fiber atrophy: altered thin filament density changes slow fiber force and shortening velocity
    D A Riley
    Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 0509, USA
    Am J Physiol Cell Physiol 288:C360-5. 2005
  10. ncbi request reprint The depressive effect of Pi on the force-pCa relationship in skinned single muscle fibers is temperature dependent
    E P Debold
    Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
    Am J Physiol Cell Physiol 290:C1041-50. 2006

Collaborators

Detail Information

Publications16

  1. ncbi request reprint Physiology of a microgravity environment invited review: microgravity and skeletal muscle
    R H Fitts
    Department of Biology, Marquette University, Milwaukee, WI 53201, USA
    J Appl Physiol (1985) 89:823-39. 2000
    ..Future studies will be required to establish the cellular and molecular mechanisms of the SF-induced muscle atrophy and functional loss and to develop effective exercise countermeasures...
  2. ncbi request reprint Spaceflight effects on single skeletal muscle fiber function in the rhesus monkey
    R H Fitts
    Department of Biology, Marquette University, Milwaukee, Wisconsin 53201, USA
    Am J Physiol Regul Integr Comp Physiol 279:R1546-57. 2000
    ..However, only SF elicited atrophy and reduced force (mN) in the MG type I fiber and a decline in relative force (kN/m(2)) in the Sol type I and MG type II fibers...
  3. pmc Prolonged space flight-induced alterations in the structure and function of human skeletal muscle fibres
    R H Fitts
    Marquette University, Department of Biological Sciences, PO Box 1881, Milwaukee, WI 53201 1881, USA
    J Physiol 588:3567-92. 2010
    ..Our results highlight the need to study new exercise programmes on the ISS that employ high resistance and contractions over a wide range of motion to mimic the range occurring in Earth's 1 g environment...
  4. ncbi request reprint Functional properties of slow and fast gastrocnemius muscle fibers after a 17-day spaceflight
    J J Widrick
    Department of Biology, Marquette University, Milwaukee 53201, Wisconsin, USA
    J Appl Physiol 90:2203-11. 2001
    ..J. Widrick, S. K. Knuth, K. M. Norenberg, J. G. Romatowski, J. L. W. Bain, D. A. Riley, M. Karhanek, S. W. Trappe, T. A. Trappe, D. L. Costill, and R. H. Fitts. J Physiol (Lond) 516: 915-930, 1999]...
  5. ncbi request reprint Unilateral lower limb suspension does not mimic bed rest or spaceflight effects on human muscle fiber function
    J J Widrick
    Department of Biology, Marquette University, Milwaukee, Wisconsin 53201, USA
    J Appl Physiol 93:354-60. 2002
    ..However, in contrast to these other models, slow soleus fibers obtained after ULLS showed a decrease in unloaded shortening velocity and a greater reduction in specific force...
  6. ncbi request reprint Functional and structural adaptations of skeletal muscle to microgravity
    R H Fitts
    Department of Biology, Marquette University, Milwaukee, WI 53201, USA
    J Exp Biol 204:3201-8. 2001
    ..The damage occurs with re-loading and not in-flight, but the etiology has not been established...
  7. ncbi request reprint The deleterious effects of bed rest on human skeletal muscle fibers are exacerbated by hypercortisolemia and ameliorated by dietary supplementation
    R H Fitts
    Dept of Biology, Marquette University, Wehr Life Sciences Bldg, PO Box 1881, Milwaukee, WI 53201 1881, USA
    Am J Physiol Cell Physiol 293:C313-20. 2007
    ..These results provide evidence that an AA/CHO supplement might serve as a successful countermeasure to help preserve muscle function during periods of relative inactivity...
  8. pmc Low cell pH depresses peak power in rat skeletal muscle fibres at both 30 degrees C and 15 degrees C: implications for muscle fatigue
    S T Knuth
    Marquette University, Department of Biological Sciences, PO Box 1881, Milwaukee, WI 53201 1881, USA
    J Physiol 575:887-99. 2006
    ....
  9. ncbi request reprint Skeletal muscle fiber atrophy: altered thin filament density changes slow fiber force and shortening velocity
    D A Riley
    Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 0509, USA
    Am J Physiol Cell Physiol 288:C360-5. 2005
    ..Osmotically compacting myofilaments with 5% dextran returned density, spacing, and specific tension and slowed V0 to near-control levels and provided evidence for myofilament spacing modulating tension and V0...
  10. ncbi request reprint The depressive effect of Pi on the force-pCa relationship in skinned single muscle fibers is temperature dependent
    E P Debold
    Department of Biological Sciences, Marquette University, Milwaukee, Wisconsin, USA
    Am J Physiol Cell Physiol 290:C1041-50. 2006
    ..Consequently, the combined changes in these ions likely account for a greater portion of fatigue than previously predicted based on studies at lower temperatures or high temperatures at saturating Ca(2+) levels...
  11. ncbi request reprint Passive stretch inhibits central corelike lesion formation in the soleus muscles of hindlimb-suspended unloaded rats
    D V Baewer
    Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, Wisconsin 53226 3548, USA
    J Appl Physiol 97:930-4. 2004
    ..05). Soleus muscle wet weight and fiber area were unaltered by stretch alone. Loaded contractions during splinting are necessary to prevent muscle fiber atrophy. Passive muscle stretch acts to maintain myofibril structural integrity...
  12. ncbi request reprint Contractile responses of the rat gastrocnemius and soleus muscles to isotonic resistance exercise
    K M Norenberg
    Dept of Biological Sciences, Marquette University, P O Box 1881, Milwaukee, WI 53201 1881, USA
    J Appl Physiol 97:2322-32. 2004
    ..These results indicate that isotonic resistance exercise of the calf targets the Gast (type I and type IIa fibers) and has little effect on the Sol...
  13. doi request reprint Effects of prolonged space flight on human skeletal muscle enzyme and substrate profiles
    R H Fitts
    Marquette University, Milwaukee, Wisconsin
    J Appl Physiol (1985) 115:667-79. 2013
    ..It is apparent that crew members performing adequate treadmill running can maintain calf muscle enzymes, which suggests that increased fatigue with weightlessness cannot be directly caused by a decline in muscle enzyme capacity. ..
  14. ncbi request reprint Fiber type and temperature dependence of inorganic phosphate: implications for fatigue
    E P Debold
    Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA
    Am J Physiol Cell Physiol 287:C673-81. 2004
    ..These data suggest that near physiological temperatures and at saturating levels of intracellular Ca(2+), elevated levels of P(i) contribute less to fatigue than might be inferred from data obtained at lower temperatures...
  15. ncbi request reprint Hindlimb unloading-induced muscle atrophy and loss of function: protective effect of isometric exercise
    J E Hurst
    Dept of Biology, Marquette Univ, Wehr Life Sciences Bldg P O Box 1881, Milwaukee, WI 53201 1881, USA
    J Appl Physiol 95:1405-17. 2003
    ..In summary, IE resulted in greater protection from HU-induced atrophy in the slow soleus than in the fast gastrocnemius or plantaris...
  16. ncbi request reprint Effects of depolarization and low intracellular pH on charge movement currents of frog skeletal muscle fibers
    E M Balog
    Department of Biology, Marquette University, Milwaukee, Wisconsin 53210, USA
    J Appl Physiol 90:228-34. 2001
    ..However, if t-tubular Ca(2+) increases, some of the charge may be stabilized in the active state and remain available to initiate sarcoplasmic reticulum Ca(2+) release...