Prostaglandin E2 receptors on human peripheral blood monocytes

The prostaglandin E2 (PGE2) receptor on human peripheral blood monocytes is characterized. The receptor binding at physiological temperature and pH was saturable, specific, and reversible. Scatchard analysis of binding data revealed a linear plot giving a Kd = 1.1 X 10(-9) mol/l and Bmax = 4.1 fmol/10(7) cells, equal to 240 binding sites per cell. PGE2 increased intracellular cyclic adenosine 5'-monophosphate by a maximal factor of 3. PGF2 alpha and arachidonic acid had no stimulatory effects on adenyl cyclase, in accordance with their low binding to the cells. The characterization of the PGE2 receptor on human monocytes creates a basis for the study of the clinical significance of changes in PGE2-receptor binding in disease states involving PGE2-monocyte interactions such as various immunological disorders and bone resorption.