TY - JOUR
T1 - The iron component of sodium nitroprusside blocks NMDA-induced glutamate accumulation and intracellular Ca2+ elevation
AU - Oh, Seikwan
AU - McCaslin, Patrick P.
PY - 1995/7
Y1 - 1995/7
N2 - These studies were designed to compare the effects of nitric oxide (NO) generating compounds with those of several iron containing, compounds which do not generate NO on glutamate receptor function. Stimulation of primary cultures of cerebellar granule cells with N-methyl-D-aspartate (NMDA) or kainate results in the elevation of intracellular calcium ([Ca2+]i) and cGMP and the release of glutamate. The iron containing compounds, sodium nitroprusside (SNP), potassium ferrocyanide (K4Fe(CN)6) and potassium ferricyanide (K3Fe(CN)6) decrease the NMDA-induced release of glutamate. SNP is the only compound of the above 3 agents which generates NO. A non-iron, NO generating compound, S-nitroso-N-acetylpenicillamin (SNAP), has no effect on the NMDA-induced glutamate release. Potassium ferrocyanide (Fe II), but not potassium ferricyanide (Fe III), blocks NMDA-induced cGMP elevations after 3 min exposure times. This contrasts with the NO generating compounds (both SNP and SNAP) which elevate cGMP levels. Furthermore, both potassium ferrocyanide (Fe II) and SNP (Fe II) suppress the elevation of [Ca2+]i induced by NMDA but neither potassium ferricyanide (Fe III) nor SNAP are effective in this regard. These effects are also independent of cyanide as another Fe II compound, ferrous sulfate (FeSO4) is also able to suppress NMDA-induced elevations of [Ca2+]i SNP was unable to suppress kainate receptor functions. Collectively, these results indicate that Fe II, independently of NO, has effects on NMDA receptor function.
AB - These studies were designed to compare the effects of nitric oxide (NO) generating compounds with those of several iron containing, compounds which do not generate NO on glutamate receptor function. Stimulation of primary cultures of cerebellar granule cells with N-methyl-D-aspartate (NMDA) or kainate results in the elevation of intracellular calcium ([Ca2+]i) and cGMP and the release of glutamate. The iron containing compounds, sodium nitroprusside (SNP), potassium ferrocyanide (K4Fe(CN)6) and potassium ferricyanide (K3Fe(CN)6) decrease the NMDA-induced release of glutamate. SNP is the only compound of the above 3 agents which generates NO. A non-iron, NO generating compound, S-nitroso-N-acetylpenicillamin (SNAP), has no effect on the NMDA-induced glutamate release. Potassium ferrocyanide (Fe II), but not potassium ferricyanide (Fe III), blocks NMDA-induced cGMP elevations after 3 min exposure times. This contrasts with the NO generating compounds (both SNP and SNAP) which elevate cGMP levels. Furthermore, both potassium ferrocyanide (Fe II) and SNP (Fe II) suppress the elevation of [Ca2+]i induced by NMDA but neither potassium ferricyanide (Fe III) nor SNAP are effective in this regard. These effects are also independent of cyanide as another Fe II compound, ferrous sulfate (FeSO4) is also able to suppress NMDA-induced elevations of [Ca2+]i SNP was unable to suppress kainate receptor functions. Collectively, these results indicate that Fe II, independently of NO, has effects on NMDA receptor function.
KW - cerebellar granule cells
KW - Cyclic GMP
KW - kainate
KW - potassium ferricyanide
KW - potassium ferrocyanide
UR - http://www.scopus.com/inward/record.url?scp=0029123349&partnerID=8YFLogxK
U2 - 10.1007/BF00969689
DO - 10.1007/BF00969689
M3 - Article
C2 - 7477670
AN - SCOPUS:0029123349
SN - 0364-3190
VL - 20
SP - 779
EP - 784
JO - Neurochemical Research
JF - Neurochemical Research
IS - 7
ER -