The Formation of Glycogen in Muscle

It would appear from theoretical considerations that muscle tissue should be incapable of forming glycogen from a disaccharid. As has been shown by a number of observers,’ the amount of inverting substance present in muscle or blood is small, or is entirely absent. The injection experiments with saccharose,2 and perfusion experiments with the liver3 also tend to show that saccharose is quite incapable of being used by the organism as a direct glycogen former. Moreover, the direct transformation of a disaccharid to a polysaccharid without the preliminary inversion to a simple hexose has not, as far as we are aware, been shown to take place. Nevertheless E. Ki,il~,~ in a series of experiments undertaken to decide this question some years ago, obtained results which in effect showed that saccharose was indeed a direct former of glycogen in muscle. It seems that the work of Kiilz, has never been repeated, although the anomalous character of the findings as recognized by him, and he asked that his observation be tested by other observers. On his authority the statement that saccharose is a direct former of glycogen has passed into the text-books, and Hammarsten, among others, mentions saccharose as an immediate antecedent in the formation of glycogen. On reference to Kiilz’s original experiments, it will be seen that the results on which he bases his statement are by no means unequivocal. Three experiments ’ Tebb: Journ. of Physiol., xv, p. 421, 1893. 2 Bernard: Lqons stir le diabkte. 3 Pfliiger: Das Glykogen, p. zag ; see also Jappelli and D’Errico: Atti Real. Accad. di Med. di Napoli, 1903, cited by Moscati, Zeitschr. f. physiol. Chem., 1, p. go, rgo6. These authors believe that saccharose is transformed into glycogen by injection into the portal vein. 4E. Ktilz: Zeitschr. f. Biol., xxvii, p. 237, 1890.