Abstract
Effects of the 105000g supernatant on adenyl cyclase of rat cerebral cortex have been investigated and following results were obtained. 1) The 105000g supernatant significantly stimulated the activity of the synaptosomal adenyl cyclase in rat cerebral cortex. As the concentration of the supernatant increased, the progressive stimulation was observed with a plateau at a concentration of about 200 μg of protein. 2) This stimulatory effect of the supernatant was completely abolished by a dialysis of the supernatant for 24 hours at 4°. 3) When the enzyme system was incubated with combination of the supernatant and norepinephrine (100 μM), no activation by norepinephrine was observed. 4) Studies on the combined effects of the supernatant and sodium fluoride (NaF) showed that the supernatant additively enhanced NaF stimulated adenyl cyclase activity. 5) Gel filtration indicated that this stimulatory substance (s) in the supernatant had a molecular weight of 1000-1300.
