Über chemische und biologische Veränderungen der Muskulatur nach öfters wiederholter faradischer Reizung. 2. Mitteilung.

Abstract

When preserved at freezing and also at somewhat higher constant temp., inorganic phosphoric acid is split off much more slowly from trained muscle than from untrained. Under the same conditions, the decrease of the power of synthesizing of hexosediphosphoric acid under the influence of NaF in glycogen-containing NaHCO3 solutions starts much later in the mash made from the trained biceps than in that made from the untrained muscle of the opposite side. Rigor mortis occurs later in trained muscle than in untrained. This could be observed in isolated muscles, and was also reflected in a characteristic, visible and palpable change in the physical condition of the muscle mash. The course of lactic acid production in the muscle mash was tried only 3 times and the observed differences are not yet sufficient for the recognition of a definite rule. In accord with the phosphoric acid production the NH3 production in the mash from trained muscle was very greatly delayed. Phosphoric acid cleavage from lactacidogen, NH3 cleavage from adenosinphosphoric acid[long dash]the latter being the only ammonia forming substance yet recognized[long dash]as well as decrease in power to synthesize hexosephosphoric acid under certain ionic conditions are processes which occur in fatigue and death of muscle. The close relationship between fatigue and death appears in the experiments of the previous research in that the difficultly fatiguable trained muscle dies more slowly than untrained. Delayed onset of rigor, delayed cleavages of inorganic phosphoric acid and NH3, and much later onset of the loss of power to synthesize hexosephosphoric acid are certainly to be considered as signs of a greater viability of the mash from trained muscle.