[In vitro formation of glycogenolytic enzyme complexes with the sarcoplasmic reticulum in the skeletal muscles of skates and the frog].

Experimental evidence is presented concerning the existence of complexes of glycogenolytic enzymes with sarcoplasmic reticulum (SR) in skeletal muscles of the skates Dasyatis pastinaca and Raja clavata and frog Rana temporaria. At various stages of preparation of kinase of glycogen phosphorylase (KGP) from ectothermic animals, in contrast to rabbit, association of KGP with the SR and glycogen granules persisted in calcium-free medium. Complex of KGP with glycogen phosphorylase and ATPase could be fractionated only during chromatographic procedure on Sepharose 4B, chromatographic pictures being distinctly different from those obtained for rabbit. It may be suggested that activation of KGP by Ca2+ in a multienzyme SR--glycogenolytic complex plays an important role in regulation of glycogenolysis in muscle tissue of skates, since hormonal stimulation of glycogen phosphorylation had not yet been described for these fishes.