LIPID MEDIATORS MODULATE NMDA RECEPTOR CURRENTS IN A XENOPUS OOCYTE EXPRESSION SYSTEM

We determined the modulatory effects of various lipid mediators on mou se N-methyl-D-aspartate (NMDA) receptor currents in the Xenopus oocyte expression system. Arachidonic acid, but not oleic acid potentiated N MDA receptor activity. The epsilon 1/zeta 1 heterodimer of the NMDA re ceptor was more sensitive to arachidonic acid than was the epsilon 2/z eta 1 heterodimer. Platelet-activating factor (PAF) and lysophosphatid ic acid (LPA) both activated the NMDA currents, and the effects were m ore evident in the epsilon 2/zeta 1 heterodimer than in epsilon 1/zeta 1. These activations were abolished by treatment with protein kinase inhibitors, suggesting a possible phosphorylation of the receptor. Thu s, lipid mediators do have modulatory effects on NMDA receptor current s, the potentiating effects of which differ depending on subtype of th e NMDA receptor. (C) 1997 Elsevier Science Ireland Ltd.