| Abstract: | Glycogen synthetase (I + D) and phosphorylase (á+b) activity was determined in human skeletal muscle biopsies with different muscle fibre composition and in dissected and pooled batches of the two main muscle fibre types: slow twitch (ST) and fast twitch (FT), respectively. Glycogen synthetase (I + D) activity remained unchanged as the per cent of FT fibres increased, but phosphorylase (á+b) activity was found to increase. A similar activity pattern was found in dissected and pooled FT fibres as compared to ST fibres, i.e. the same glycogen synthetase activity but heightened phosphorylase activity. |
