Acetylcholine stimulation on phosphatidylinositol inositol phosphohydrolase of rat brain cortex.

O. CANESSA DE SCARNATI ; G. RODRÍGUEZ DE LORES ARNAIZ

Biochem Biophys Acta

ELSEVIER

Año: 1972 vol. 270 p. 218 - 225

0006-3002

1. The aim of the present paper was to study if the known effect of acetylcholine on phosphatidylinositol turnover involved the stimulation of the enzymic hydrolysis of phosphatidylinositol.2. As a first step the distribution of phosphatidylinositol-inositol phosphohydrolase in subcellular fractions from the rat cerebral cortex was investigated. It was found that the enzyme was essentially particle bound with the higher concentration in the cholinergic nerve-ending membranes, following the distribution of acetylcholinesterase.3. A marked effect of acetylcholine on phosphatidylinositol-inositol phosphohydrolase activity was observed in the crude nerve-ending membrane and soluble fractions. The type of effect was dependent on the concentration: 10-7 to 10-5 M acetylcholine enhanced the activity while 10-3 M produced considerable inhibition.4. The results favour the hypothesis that acetylcholine affects the turnover of phosphatidylinositol during the transmission process.