INTERRELATION OF PHOSPHOINOSITIDE METABOLISM AND ION TRANSPORT IN CRAB NERVE FIBRES¹

Abstract

Abstract— The effects of acetylcholine (ACh) on phosphoinositide metabolism and associated changes in nerve fibre membranes of Carcinus maenas and Eriphia spinifrons were studied. It was shown that as the content of triphosphoinositide in ACh‐treated crab nerve fibre decreased, the permeability of the fibres to K + increased, which led to nerve fibre depolarization. Proserini protected nerve fibres against the effect of ACh. These observations appear to implicate the participation of acetylcholinesterase in triphosphoinositide hydrolysis. Our results indicate that phosphoinositides participate in the control of the permeability of crab nerve fibres to potassium ions.