Dopamine D₁-like receptors play only a minor role in the increase of striatal dopamine induced by striatally applied SKF38393.
We studied the effects of the intra-striatal infusion of Ca(2+)-free medium on the intra-striatal injection of 0.5 μg SKF38393-induced striatal dopamine efflux. It is discussed that the amount of extracellular, striatal dopamine seen after striatally applied SKF38393, is the overall result of the (a) release of dopamine from the alpha-methyl-para-tyrosine-sensitive and Ca(2+)-insensitive pool of newly synthesised dopamine, (b) release of dopamine from the reserpine-sensitive and Ca(2+)-sensitive storage pool, (c) inhibition of uptake of dopamine into nerve terminals and glial cells, and (d) facilitation respectively of the inhibition of uptake into blood vessels: dopamine D₁-like receptors play only a very limited role in these processes. The present study underlines our previous notion that the effects of SKF38393 cannot simply be ascribed to the dopamine D₁-like receptor stimulation (Saigusa et al., 2009): in fact, the present study clearly reveals that SKF38393 is not at all selective in that respect.
Sekino
Reiko
R
Department of Anaesthesiology, Nihon University School of Dentistry, 1-8-13, Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
Saigusa
Tadashi
T
Aono
Yuri
Y
Uchida
Takuya
T
Takada
Koji
K
Oi
Yoshiyuki
Y
Koshikawa
Noriaki
N
Cools
Alexander R
AR
D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine / Q000008:administration & dosage* / Q000494:pharmacology*; D000818:Animals; D001160:Arterioles / Q000187:drug effects / Q000378:metabolism / Q000502:physiology; D001552:Benzazepines / Q000008:administration & dosage / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D005110:Extracellular Space / Q000187:drug effects / Q000378:metabolism; D005259:Felypressin / Q000494:pharmacology; D066298:In Vitro Techniques; D007267:Injections; D007552:Isotonic Solutions / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D017072:Neostriatum / Q000098:blood supply / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D010109:Oxymetazoline / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000378:metabolism*; D017483:Receptors, Vasopressin / Q000378:metabolism; D000077331:Ringer's Solution; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014699:Venules / Q000187:drug effects / Q000378:metabolism / Q000502:physiology
D001552:Benzazepines; D007552:Isotonic Solutions; D017447:Receptors, Dopamine D1; D017483:Receptors, Vasopressin; C534628:SCH 23390; D014662:Vasoconstrictor Agents; D005259:Felypressin; D015647:2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-benzazepine; D000077331:Ringer's Solution; D010109:Oxymetazoline; D004298:Dopamine