Hypoxia modulates nitric oxide-induced regulation of NMDA receptor currents and neuronal cell death


Journal Article

Nitric oxide (NO) released from a new chemical class of donors enhances N-methyl-D-aspartate (NMDA) channel activity. Using whole cell and single- channel patch-clamp techniques, we have shown that (Z)-1-[N(3-ammoniopropyl)- N-(n-propyl)amino]-NO (PAPA-NO) and diethylamine NO, commonly termed NONOates, potentiate the glutamate-mediated response of recombinant rat NMDA receptors(NR1/NR2A) expressed in HEK-293 cells. The overall effect is an increase in both peak and steady-state whole cell currents induced by glutamate. Single-channel studies demonstrate a significant increase in open probability but no change in the mean single-channel open time or mean channel conductance. Reduction in oxygen levels increased and prolonged the PAPA-NO-induced change in both peak and steady-state glutamate currents in transfected HEK cells. PAPA-NO also enhanced cell death in primary cultures of rodent cortical neurons deprived of oxygen and glucose. This potentiation of neuronal injury was blocked by MK-801, indicating a critical involvement of NMDA receptor activation. The NO-induced increase in NMDA channel activity as well as NMDA receptor-mediated cell death provide firm evidence that NO modulates the NMDA channel in a manner consistent with both a physiological role under normoxic conditions and a pathophysiological role under hypoxic conditions.

Duke Authors

Cited Authors

  • Gbadegesin, M; Vicini, S; Hewett, SJ; Wink, DA; Espey, M; Pluta, RM; Colton, CA

Published Date

  • November 19, 1999

Published In

Volume / Issue

  • 277 / 4 46-4

International Standard Serial Number (ISSN)

  • 0363-6143

Citation Source

  • Scopus