Effects of N- and C-terminal fragments of substance P on ATPase and monoamine oxidase activities in rat brain

Abstract

The in vitro influence of substance P (SP) C- and N-terminal fragments on the Na +,K +-ATPase and Ca 2+,Mg 2+-ATPase and monoamine oxidase (MAO) from synaptosomal membrane and extra-synaptosomal mitochondria were studied. The obtained results indicate: 1. C-terminal fragment of SP (SP 6–11) in 10 μM concentration stimulates the Ca 2+,Mg 2+-ATPase activities from cerebral cortex and hippocampus. Na +,K +-ATPase from cerebral cortex is hardly sensitive to the action of this fragment. 2. N-terminal fragment of SP (SP 1–5) in 10 μM concentration increases Na +,K +-ATPase activity from cerebral cortex and hippocampus. 3. N-terminal tetrapeptide (SP 1–4) exerts no influence on ATPases independently from their brain localization. 4. The activity of monoamine oxidase after use of C- and N-terminal fragments is unchanged.