Involvement of D1 dopamine receptor mechanism in ischemia-induced impairment of CA1 presynaptic fiber spikes in rat hippocampal slices.
The effect of dopamine (DA) receptor agonists and antagonists on hypoxia/hypoglycemia (ischemia)-induced decrease in CA1 presynaptic fiber spikes elicited by the stimulation of Schaffer collateral were investigated using hippocampal slices. Treatment with D1 dopamine receptor antagonist, SCH23390 produced a concentration-dependent attenuation of the ischemia-induced decrease of presynaptic potentials. The magnitude of recovery of the CA1 presynaptic potential in SCH233390-treated slices at 10 and 100 microM was 28 and 54%, respectively. Whereas, treatment with D1 dopamine receptor agonist, SKF38393 exacerbated the ischemia-induced decrease in the CA1 presynaptic potential. The decrease of CA1 presynaptic potential by ischemia was affected by neither D2 dopamine receptor agonist, bromocriptin and quinpirole nor D2 dopamine receptor antagonist, sulpiride. The neuroprotective effect of SCH23390 was completely blocked by cotreatment with SKF38393. The present results demonstrated that the blockade of D1 dopamine receptor function played a neuroprotective role in ischemic damage, suggesting a facilitatory role of D1 dopamine receptor-operated function in ischemia-induced neuronal deficits.
Yamamoto
Y
Y
Department of Pharmacology, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan.
Tanaka
T
T
Shibata
S
S
Watanabe
S
S
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000494:pharmacology; D000200:Action Potentials / Q000502:physiology; D000704:Analysis of Variance; D000818:Animals; D001552:Benzazepines / Q000494:pharmacology; D002545:Brain Ischemia / Q000503:physiopathology*; D001971:Bromocriptine / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D004873:Ergolines / Q000494:pharmacology; D006624:Hippocampus / Q000098:blood supply / Q000503:physiopathology*; D066298:In Vitro Techniques; D008297:Male; D009412:Nerve Fibers; D017729:Presynaptic Terminals / Q000502:physiology*; D019257:Quinpirole; D051381:Rats; D017208:Rats, Wistar; D017447:Receptors, Dopamine D1 / Q000187:drug effects / Q000502:physiology*; D013469:Sulpiride / Q000494:pharmacology
D001552:Benzazepines; D018491:Dopamine Agonists; D004873:Ergolines; D017447:Receptors, Dopamine D1; D019257:Quinpirole; D001971:Bromocriptine; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D013469:Sulpiride