Volume changes in frog muscle during contraction

Abstract

The variation in volume when a muscle contracts was the subject of much discussion towards the end of the 17th century, and more recently by Fulton (1926) and by Ernst (1958). Many scholars expected an increase in volume as the vital spirits moved from the nerve into the muscle and induced activation: but Swammerdam (ca. 1660) experimented with an isolated muscle contained in a jar with a fine-bore tube attached and in fact observed a slight decrease in volume. Ernst (1925) first demonstrated the decrease with certainty and set the stage for many investigations of volume change in frog striated muscle. Meyerhof & Hartmann (1934) showed that the volume decrease during tetanic contraction parallelled the development of tension, and that a further decrease accompanied maintenance of the tension. They also made precise studies of the slow changes in volume which occur following mechanical activity. These were related quantitatively to the formation of lactic acid under anaerobic conditions and to the break-down of creatine phosphate in an iodoacetate-poisoned muscle. Fischer (1941), on the other hand, reported the occurrence of a volume increase as well as a decrease during contraction, but this was not confirmed by Ernst. All the authors found a volume decrease of about 0-002 % of the muscle volume during a short tetanus, but the response of the apparatus was too slow to record the precise time relationships of the change during contraction. A tetanus was necessary in order to obtain a change large enough to record; the muscles used were almost always large gastrocnemii and usually several muscles were necessary. Hill (1948) has criticized this choice: the fibres in the gastrocnemius muscle do not run parallel through the length of the muscle but instead are arranged at an angle to the axis of the muscle, so that during contraction a portion of the muscle tension would be directed at right angles to the axis of the muscle, thus producing an internal pressure. This was demonstrated by Hill and can also be substantiated by the observation in mammals that during

The dependence of the latency relaxation on sarcomere length and other characteristics of isolated muscle fibres

“…The present finding that glycerol disruption abolishes the LR in single fibres or whole muscle makes it unlikely that the LR can arise in the sarcolemma as suggested by Hill (1951). Furthermore, his proposal that this structure might expand longitudinally is not supported by the present finding that Rmax is not corre-351 LOUIS A. MULIERI lated with Iref* The latter observation also argues against proposals attributing the LR to the early myoplasmic volume changes that occur during the latent period (Abbott & Baskin, 1962;Davies, 1963;Baskin & Paolini, 1966;Peachey, 1968). Since a fibre with more sarcomeres in series, i.e.…”

The length, width and volume of isolated rat and ferret ventricular myocytes during twitch contractions and changes in osmotic strength

“…During an isometric or isotonic tetanus all authors have observed a small decrease in the muscle volume of about 0-005 %. During an isometric twitch of skeletal muscle Abbott & Baskin (1962) observed a smaller decrease in volume of about 0-0005 %. The volume changes measured in this way can only be the result of compression or chemical reactions that result in a smaller volume, such as the break-down of creatine phosphate (Meyerhof, 1947); changes in volume as the result of a shift of water between the extracellular and intracellular spaces will not be detected.…”

“…The muscle volume was expected to increase, because the vital spirits were thought to move from the nerve into the muscle to induce activation (for references see Abbott & Baskin, 1962). In about 1660 Swammerdam experimented on an isolated muscle in a fluid-filled chamber and observed a small decrease in muscle volume as indicated by a drop in the level of solution.…”

Direct Evidence that Left Ventricular Myocardium Is Incompressible Throughout Systole and Diastole

“…However, whether myocardium is incompressible or not has not been well demonstrated. That skeletal muscle is practically incompressible during contraction has been accurately shown (Abott and Baskin 1962). Utilizing a sophisticated technique which permitted the measurement of small, rapid volume changes occurring in a muscle during a twitch, they reported in the sartorius muscle that the transient increase which commences at between 2 and 3 msec after the stimulus is about 2.5 x 10-6 and that the decrease during a twitch is about 5 x 10-6 ml/g.…”