Stan L. Lindstedt, PhD

Lindstedt

Regents' Professor 
Phone: 928-523-7524
Email: Stan.Lindstedt@nau.edu
Office: Chemistr, bldg. 20 room 426
Personal website 

Research/teaching interests

  • comparative physiology
  • muscle plasticity
  • body-size constraints on function

Academic highlights

The primary research interest in our laboratory is the adaptive plasticity of vertebrate skeletal muscle. How is it that muscle adapts to the nature and intensity of the demands placed upon it?

These changes involve shifts in metabolic properties such as the densities of capillaries and mitochondria as well as contractile properties such as the force, velocity and efficiency of contraction.

Skeletal muscle is remarkable in part because shifts in very few structural components result in outcomes as diverse as muscles designed for burst power, high frequency or posture, heat or sound production, to name just a few. To investigate these properties of muscle, our research involves a variety of techniques as well as animal and human models.

Techniques involve physiological investigation of work output and oxygen consumption; quantitative ultrastructure with the electron microscope and biochemical investigation of myosin isozymes and ATPase activity; and finally, we use NMR spectroscopy to investigate high energy phosphate regulation of aerobic muscle energetics. In addition to varing oxygen demand, we examine the impact of varying oxygen availability (i.e., altitude-induced hypoxia).

Our model systems include the rattlesnake tail-shaker muscle; chronic cold exposure in mammalian muscle (muscle as a heater organ) and investigation of respiratory and locomotor muscle adaptation in humans.

A shock absorber functions as a damper when a noncompressible fluid is driven past a piston, converting kinetic energy to heat. If the shock absorber is in series with a spring, then stretching the spring-shock results in tension on the spring or extension of the shock, depending on both the magnitude and time course of the force produced.

When an active muscle is lengthened during an eccentric contraction, it behaves like a shock absorber-spring complex. In hiking downhill, nearly all of the energy that stretches the active muscle is lost as heat (extension of the shock).

In contrast, running mammals store most of the energy required to stretch the muscle as elastic recoil potential energy (extension of the spring), which can be recovered on the subsequent stride.

The time course of stretch and recovery of elastic recoil energy are dependent on both the magnitude of the forces involved as well as the compliance (spring property) of the muscle. As both of these properties are body size dependent, small animals move with predictably higher stride frequencies than do large animals.

S. L. Lindstedt, P. C. LaStayo and T. E. Reich

News in Physiological Sciences 16: 256-261, 2001.

Selected publications

Moon, B.R., K.E. Conley, S.L. Lindstedt and M.R. Urquhart (2003) Minimal shortening in a high-frequency muscle. J. Expl. Biol. 206: 1291-1297.

LaStayo, P.C., G. Ewy, D. Pierotti, R. Johns, S.L. Lindstedt (2003) The Positive Effects of negative work: Increased muscle strength and decreased fall-risk in a frail-elderly population. J. Gerontology 58A: 419-424.

LaStayo, P.C., J. Woolf, M.D. Lewek, L. Snyder-Mackler, T. Reich, S.L. Lindstedt. (2003) Eccentric muscle contractions: Their contribution to injury prevention rehabilitation and sport. J Ortho Sport Phys Ther, 33: 557-571.

Schaeffer, P.C., J.J. Villarin and S.L. Lindstedt (2003) Chronic cold exposure increases skeletal muscle oxidative structure and function in Monodelphis domestica, a marsupial lacking brown adipose tissue. Physiological and Biochemical Zoology 76: 877-887.

Villarin, J.J., P.J. Schaeffer, R.A. Markle, S.L. Lindstedt (2003) Potential contribution of liver tissue to aerobic energy balance following chronic cold exposure in the marsupial, Monodelphis domestica. Comp. Biochem. Physiol. A 136: 621-630.