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Sulphur-containing excitatory amino acid-stimulated inositol phosphate formation in primary cultures of cerebellar granule cells is mediated predominantly by N-methyl-d-aspartate receptors
| Content Provider | Semantic Scholar |
|---|---|
| Author | Gorman, Adrienne M. Griffiths, Roger |
| Copyright Year | 1994 |
| Abstract | The stimulatory effect of excitatory sulphur-containing amino acids on inositol phosphate formation was investigated in primary cultures of cerebellar granule cells. L-Cysteine sulphinate (CSA), L-cysteate (CA), L-homocysteine sulphinate (HCSA), L-homocysteate (HCA) and S-sulpho-L-cysteine (SSC) dose-dependently stimulated the formation of [3H]inositol phosphates exhibiting EC50 values in the range 60-200 microM and maximal effects of six- to 17-fold that of basal [3H]inositol phosphate levels. Endogenous L-glutamate spontaneously released into the extracellular medium or following exposure of cells to HCSA, HCA or SSC did not contribute significantly to formation of [3H]inositol phosphates, whereas 10% of the total [3H]inositol phosphates accumulated following exposure to CSA and CA was due to released L-glutamate. The selective N-methyl-D-aspartate receptor antagonist, D,L-2-amino-5-phosphonopentanoic acid (APV, 500 microM) attenuated by 20% (HCSA) to between 80 and 100% (CSA, CA, SSC, HCA) the formation of [3H]inositol phosphates induced by 1 mM sulphur-containing amino acids. When, however, HCSA was used at 100 microM (a concentration near to its EC50 for phosphoinositide hydrolysis), APV inhibited induced responses by 70%. Sulphur-containing amino acid-stimulated [3H]inositol phosphate formation was unaffected by the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX, 10 microM). Inhibition of sulphur-containing amino acid-stimulated [3H]inositol phosphate formation by co-administration of APV and CNQX was similar to that obtained in the presence of APV alone. CSA-, CA-, SSC- and HCA-stimulated [3H]inositol phosphate formation was markedly reduced by removal of Ca2+ from the extracellular medium whereas that stimulated by HCSA was less affected. A similar inhibitory profile was observed when the levels of sulphur-containing amino acid-induced increases in intracellular free calcium ([Ca2+]i) were measured in the presence of 500 microM APV; 1 mM HCSA-induced responses being inhibited by only 30% whereas responses to the remaining sulphur-containing amino acid (also at 1 mM) were inhibited by > 45%. When the sulphur-containing amino acids were used at concentrations approximating their EC50 values for phosphoinositide hydrolysis, APV inhibited the induced increases in [Ca2+]i by 70-100%. HCA and SSC co-administered with the less efficacious but selective metabotropic glutamate receptor agonist, (+-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD) at maximally effective concentrations (1 mM) of each agonist stimulated [3H]inositol phosphate formation in an additive manner.(ABSTRACT TRUNCATED AT 400 WORDS) |
| Starting Page | 299 |
| Ending Page | 308 |
| Page Count | 10 |
| File Format | PDF HTM / HTML |
| PubMed reference number | 8008194 |
| Journal | Medline |
| Volume Number | 59 |
| Alternate Webpage(s) | https://api.elsevier.com/content/article/pii/0306452294905983 |
| Alternate Webpage(s) | https://www.sciencedirect.com/science/article/pii/0306452294905983?dgcid=api_sd_search-api-endpoint |
| Alternate Webpage(s) | https://doi.org/10.1016/0306-4522%2894%2990598-3 |
| Journal | Neuroscience |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
