Receptors for phorbol esters are primarily localized in neurons: comparison of neuronal and glial cultures.

Binding of [3H]PDB has been measured in the present study to determine the levels of protein kinase C in the neuronal and astrocytic glial cells in culture from rat brain. Binding of [3H]PDB to homogenates of cultured neuronal cells from the brains of normotensive and hypertensive rats was time-dependent and specific. The relative potency for competition by various phorbol esters to [3H]PDB binding was TPA greater than beta-PDD greater than POE greater than alpha-PDD greater than or equal to 4 alpha phorbol. Scatchard analysis showed that neuronal cultures from normotensive rat brains contained 2-3 fold more phorbol ester receptors compared with the glial cultures from the same brains. No differences in the Kd and Bmax were observed between neuronal cultures from normotensive and spontaneously hypertensive rat brains. These studies suggest that the phorbol ester receptors are primarily localized in neuronal cells.