TY - JOUR
T1 - Further evidence against the coupling of dopamine receptors to phosphoinositide hydrolysis in rat striatum
AU - Rubinstein, Joan E.
AU - Hitzemann, Robert J.
N1 - Funding Information:
Acknowledgements-This work was supported by PHS PhysicianS cientistA ward Kll MH 00747(t o J. E. R.) and by PHS Grant MH 43385a nd the VeteransA dministration ResearchS ervice( to R. J. H.).
PY - 1990/6/15
Y1 - 1990/6/15
N2 - The effects of D1 and D2 dopamine receptor agonists on phosphoinositide hydrolysis were studied by measuring the accumulation of radioactive inositol phosphates in slices of rat corpus striatum prelabelled with [3H]inositol. All assays were performed in the presence of lithium. Neither the D1 receptor agonist SKF 38393 nor the D2 receptor agonist quinpirole, alone or in combination, had an effect on basal accumulation of inositol phosphates. The muscarinic receptor agonist carbachol produced a robust increase in the accumulation of inositol monophosphate and a smaller increase in the accumulation of inositol bisphosphate. These effects were not altered by the presence of quinpirole. Additionally, quinpirole also had no effect when assays were conducted in the presence of the muscarinic receptor antagonist scopolamine, the glutamic acid receptor antagonist kynurenic acid, and the antioxidant glutathione. These results are discussed in relation to recent contradictory reports and lend support to the position that D2 dopamine receptors are not coupled to phosphoinositide hydrolysis in rat striatum.
AB - The effects of D1 and D2 dopamine receptor agonists on phosphoinositide hydrolysis were studied by measuring the accumulation of radioactive inositol phosphates in slices of rat corpus striatum prelabelled with [3H]inositol. All assays were performed in the presence of lithium. Neither the D1 receptor agonist SKF 38393 nor the D2 receptor agonist quinpirole, alone or in combination, had an effect on basal accumulation of inositol phosphates. The muscarinic receptor agonist carbachol produced a robust increase in the accumulation of inositol monophosphate and a smaller increase in the accumulation of inositol bisphosphate. These effects were not altered by the presence of quinpirole. Additionally, quinpirole also had no effect when assays were conducted in the presence of the muscarinic receptor antagonist scopolamine, the glutamic acid receptor antagonist kynurenic acid, and the antioxidant glutathione. These results are discussed in relation to recent contradictory reports and lend support to the position that D2 dopamine receptors are not coupled to phosphoinositide hydrolysis in rat striatum.
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U2 - 10.1016/0006-2952(90)90616-S
DO - 10.1016/0006-2952(90)90616-S
M3 - Article
C2 - 1972328
AN - SCOPUS:0025370085
SN - 0006-2952
VL - 39
SP - 1965
EP - 1970
JO - Biochemical Pharmacology
JF - Biochemical Pharmacology
IS - 12
ER -