The formation of cyclic inositol 1,2-monophosphate, inositol 1-phosphate, and glucose 6-phosphate by brain preparations stimulated with deoxycholate and calcium: a gas chromatographic study

A gas chromatographic method has been developed for the separation and isolation of water-soluble phosphates as trimethylsilyl ethers. With this method cyclic inositol 1,2-monophosphate and inositol 1-phosphate, derived from endogenous phosphatidylinositol, have been shown to increase when a particulate portion of brain homogenate is stimulated with deoxycholate and Ca⁺⁺, confirming earlier observations of Lapetina and Michell (1). Concomitant with the appearance of inositol phosphates is the stimulated formation of glucose 6-phosphate in the whole homogenate. Although ATP can replace deoxycholate and Ca⁺⁺ in a dialyzed homogenate, glucose 6-phosphate apparently does not arise by any known metabolic pathway but from another unidentified source.