Changes in protein kinase C and adenylate cyclase in the temporal lobe from subjects with schizophrenia.

Changes in G-protein linked neurotransmitter receptors have been reported in a number of regions of the brain of schizophrenic subjects. These changes, if functional, could cause a change in proteins such as protein kinase C (PKC) and adenylate cyclase (AC) which are important components of the G-protein linked second messenger cascades. We therefore used autoradiography to measure the distribution and density of [3H]phorbol ester binding to PKC and [3H]forskolin binding to AC in tissue obtained at autopsy from schizophrenic and non-schizophrenic subjects (Controls). There were significant decreases in the density of PKC in the parahippocampal gyrus (687 +/- 60 vs. 885 +/- 51 fmol/mg TE; mean +/- SEM; p < 0.01) and in AC in the dentate gyrus (75 +/- 4.9 vs. 92 +/- 6.5, p < 0.05) from the schizophrenic subjects. These data could indicate that changes in neurotransmitter receptors in the hippocampus from subjects with schizophrenia could have resulted in a change in their associated second messenger systems.