High density of prostaglandin E2 binding sites in the anterior wall of the 3rd ventricle: a possible site of its hyperthermic action.

Prostaglandin E2 (PGE2) exerts a potent hyperthermic action when injected into the preoptic-hypothalamic area (POHA) and is considered to be a central mediator of fever. To determine the exact functional sites of PGE2, we used in vitro quantitative autoradiography of [3H]PGE2 binding sites in the rat POHA. The highest density of [3H]PGE2 binding was found in the regions of the anterior wall of the 3rd ventricle (A3V). Within the A3V, binding density was especially high in regions closest to the third ventricle or surrounding the organum vasculosum laminae terminalis (OVLT) but was relatively low within the OVLT itself. It seems likely that the A3V PGE2 binding sites identified in this study are responsible for PGE2 mediation of fever.