Oxidative enzymes and myosin-ATPase in the trunk musculature of the river lamprey (Lampetra fluviatilis).

The distribution and activities of several oxidative enzymes and of myosin-ATPase have been studied in the trunk musculature of the river lamprey. The strongest activity of oxidative enzymes and of myosin-ATPase was shown by the parietal fibre bundles of the myotomal subunits, whilst the central fibres reacted to a lesser extent. Pre-incubation of sections in media containing formaldehyde and glycine or with buffers of different pH, followed by incubation for myosin-ATPase, also differentiated the muscle fibres into a specific distribution pattern within the myotomes, resembling that of the oxidative enzymes to some extent. The parietal fibres were found to be of the slow type (type I) and the cental fibres to be fast (type II A).