Role of synaptophysin in exocytotic release of dopamine from Xenopus oocytes injected with rat brain mRNA.
1. The role of synaptophysin in the exocytotic release of dopamine (DA) was examined in Xenopus laevis oocytes injected with rat brain mRNA. 2. The mRNA-injected oocytes showed DA uptake which depended on the incubation time and external DA concentrations. 3. Stimulation with KCl (10-50 mM) of mRNA-injected oocytes preloaded with DA evoked external Ca2+ -dependent release of DA. The noninjected and water-injected oocytes did not produce uptake of DA and stimulation-evoked release of DA. 4. The high-KCl (50 mM)-stimulated release of DA decreased in the oocytes injected with rat brain mRNA together with antibody to synaptophysin. 5. Immunoblot analysis demonstrated that synaptophysin was expressed in the brain mRNA-injected oocytes but not in the noninjected and water-injected oocytes. 6. Thus, uptake and release machinery similar to native dopaminergic nerve terminals was expressed in Xenopus oocytes by injecting mRNA-extracted from the rat brain, and synaptophysin may play a role in the exocytotic release of DA.
Shibaguchi
H
H
Department of Pharmacology, Nagasaki University School of Medicine, Japan.
Takemura
K
K
Kan
S
S
Kataoka
Y
Y
Kaibara
M
M
Saito
N
N
Taniyama
K
K
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects / Q000502:physiology; D001923:Brain Chemistry / Q000235:genetics*; D004298:Dopamine / Q000493:pharmacokinetics*; D005089:Exocytosis / Q000187:drug effects / Q000502:physiology*; D008297:Male; D009865:Oocytes / Q000378:metabolism; D011189:Potassium Chloride / Q000494:pharmacology; D012333:RNA, Messenger / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D016708:Synaptophysin / Q000276:immunology / Q000378:metabolism*; D014316:Tritium; D014982:Xenopus laevis
D000906:Antibodies; D012333:RNA, Messenger; D016708:Synaptophysin; D014316:Tritium; D015102:3,4-Dihydroxyphenylacetic Acid; D011189:Potassium Chloride; D004298:Dopamine