[Glycogen content and activities of phosphorylase and glucose-6-phosphatase in the fast and slow muscles of representatives of different classes of vertebrates].

Studies have been made on glycogen content as well as on the activity of phosphorylase and glucose-6-phosphatase in fast and slow muscles from representatives of 6 classes of vertebrates (Lampetra fluviatilis, Cyprinus carpio, Rana temporaria, Rana ridibunda, Emys orbicularis, hen, rat). Glycogen level and glucose-6-phosphatase activity are either higher in slow muscles, or practically identical in both types of muscles (glucose-6-phosphatase is absent from the fast muscles of hens and rats). On the contrary, phosphorylase activity is higher in fast muscles, this finding being true only for higher vertebrates and lampreys.