Regional cyclic GMP content in incubated tissue slices of rat brain.

Incubated tissue slices from different regions of the rat brain contained cyclic guanosine 3',5'-monophosphate (cyclic GMP) in the following descending order of content: cerebellum greater than hypothalamus greater than striatum greater than thalamusmidbrain greater than brain stem greater that hippocampus greater than cerebral cortex. Cholinomimetic agents at 10(-5) M (carbamylcholine, pilocarpine, acetylcholine and eserine) and papavering at 14(-4) M significantly elevated cyclic GMP accumulation in the cerebral cortex. Three min incubation with carbamylcholine (10(-5) M) did not increase cyclic nucleotide accumulation in the remaining brain regions.