Desensitization of PGE1 receptors in neuroblastoma-glioma hybrid cells

Prostaglandin E₁ receptor sites were measured in homogenates of NG108-15 neuroblastoma-glioma hybrid cells after exposure of intact cells to PGE₁. Scatchard analysis of competitive binding studies showed that incubation of NG108-15 cells in the presence of 2.5 μM PGE₁ for 16 h resulted in a loss of PGE₁ receptors and an increase in the dissociation constant of the remaining receptors. Thus, cells challenged with PGE₁ not only lose adenylate cyclase activity, but also lose PGE₁ receptors and decreased the affinity of the remaining receptors for PGE₁.