Sarcoplasmic Proteins in Pale, Exudative Pig Muscles

Abstract

AMONG the histological aspects of the so-called white muscle disease or ‘Muskeldegeneration’ (pale, exudative muscle)¹ is the presence of dark bands which cross the muscle fibres when these are seen in longitudinal section^2,3. Bendall and Wismer-Pedersen³ presented evidence that these bands consisted of denatured sarcoplasmic protein. The denatured proteins appeared to be precipitated on to the myofibrils under the conditions of relatively low pH and high temperature, which obtain during post-mortem glycolysis in this disorder. It has recently been shown, using starch-gel electrophoresis, that various glycolytic enzymes, including creatine kinase, are among the sarcoplasmic proteins which precipitate in exudative pork⁴. These proteins remain soluble if the temperature during post-mortem glycolysis is relatively low or, irrespective of temperatures up to 37° C, if the ultimate pH is high.