Phospholipid labelling by ( 32 P)-orthophosphate and ( 3 H)-myo-inositol in the stimulated goldfish brain in vivo.

THE RAPID turnover of phosphatidate (PhA) and phosphatidyl inositol (PhI) in neural tissue has been related to synaptic function by a number of observations. Increased incorporation of labelled phosphate into these lipids has been reported when cholinergic agents are added to incubated slices of brain (BROSSARD and QUASTEL, 1963; HOKIN and HOKIN, 1955), to homogenates (REDMAN and HOKIN, 1964; DURELL and SODD, 1964), and to synaptic nerve-ending preparations (SCHACHT and AGKANOFF, 1972). Stimulation of labelling of PhI and PhA has also been reported in brain slices (PUMPHREY, 1969) and in excised sympathetic ganglia (LARRABEE and LEICHT, 1965) that have been stimulated electrically. Although these findings suggest that functional activity in the intact brain could affect phospholipid turnover, there have been few studies in vivo. In the present paper, we report the effect of pentylenetetrazol and electrically-produced convulsions on incorporation of [32P]-orthophosphate and [3H]-nz.yo-inositol into brain phospholipids at various times following injection of isotope.