Catechol, a structural requirement for (Na+ + K+)-ATPase stimulation in rat skeletal muscle membrane.

1. Catecholamines can nearly double (Na+ + K+)-ATPase acts effect is not mediated by cyclic AMP and is not beta-adrenergic. 3. Orthodihydroxybenzene compounds and their orthoquinone derivatives enhance (Na+ + K+)-ATPase activity. 4. Enhancement of (Na+ + K+)-ATPase activity by catechols is not due to increased availability of ATP. 5. It is suggested that catechols and their orthoquinones somehow alter or protect the configuration of the enzyme so that it becomes more active or so protect the configuration of the enzyme so that it becomes more active or so that its activity is maintained under conditions in which its activity is otherwise diminished.