Effects of various agents on synaptosomal adenylate cyclase activity in the absence and presence of the boiled supernatant.

A study was made of the effects of various agents on adenylate cyclase in synaptosomes in both the absence and presence of the boiled supernatant from rat cerebral cortex. The activity of adenylate cyclase in these preparations was inhibited by the sulfhydryl reactive agent p-chloromercuribenzoate. Sulfhydryl compounds such cysteine, glutathione and Coenzyme A stimulated the enzymic activity in both the absence and presence of the boiled supernatant. The chelating agent 1.2-bis-(2-dicarboxymethylaminoethoxy)ethane caused a stimulation of the enzymic activity with and without the presence of the boiled supernatant. Adenine nucleotide (adenine, adenosine, AMP and ADP), GTP, Pi and carbamylcholine seemed to have little effect. The stimulatory substance in the boiled supernatant was estimated to have a molecular weight in the range of 1,000-1,300.