The Force-Velocity Relation of Rat Fast- And Slow-Twitch Muscles Examined at Different Temperatures

J Physiol. 1984 Jun;351:517-29. doi: 10.1113/jphysiol.1984.sp015260.

Abstract

The steady-state force-velocity relation was examined at temperatures between 35 and 10 degrees C in rat fast-twitch (extensor digitorum longus, e.d.l.) and slow-twitch (soleus) muscle preparations in vitro, with direct stimulation, and employing the isotonic release technique. The curvature of the force-velocity relation increased with cooling in both muscles; the increase was more pronounced below 25 degrees C. The maximum shortening velocity of e.d.l. muscle decreased with a Q10 (temperature coefficient) of 1.8 in cooling from 35 to 25 degrees C; it decreased with a Q10 of 2.4 in cooling below 20 degrees C. The shortening velocity of slow muscle was more temperature sensitive. The Q10 values for soleus muscle were 2.0 at 35-25 degrees C and 3.5 below 20 degrees C. The maximum rate of isometric tetanic tension rise had a temperature sensitivity similar to the maximum velocity of shortening in each muscle type.

MeSH terms

  • Animals
  • Biomechanical Phenomena
  • Hindlimb
  • In Vitro Techniques
  • Isometric Contraction
  • Isotonic Contraction
  • Male
  • Muscle Contraction*
  • Muscles / physiology*
  • Rats
  • Temperature*