A System for Measuring Contractions of the Rat Ventricle Strip*

Abstract

A system is described for the quantitative measurement of the contractions of the electrically driven rat ventricle strip. The apparatus includes the components of the transducer-amplifier-recording system as well as a simplified muscle-holder and electrode assembly. As normally employed, the system accurately measures semi-isometric (>0.025 mm. displacement) muscle contractions at a stimulus frequency of four per second. It may also be employed at other frequencies and for moderate isotonic contractions as well as for gas displacement.