Kw. Kim et al., CA2-DEPENDENT AND CA2+-INDEPENDENT MECHANISMS OF ISCHEMIA-EVOKED RELEASE OF [H-3] DOPAMINE FROM RAT STRIATAL SLICES(), Clinical and experimental pharmacology and physiology, 22(4), 1995, pp. 301-302
1. Ischaemia was induced by 5 min of deprivation of glucose and an add
itional 5 min of deprivation of glucose and oxygen from Mg2+-free arti
ficial cerebrospinal fluid in vitro. 2. During the ischaemic period, 1
1 +/- 1.5% of the total [H-3]-dopamine ([H-3]-DA) was released into th
e incubation medium. 3. Ischaemia-evoked release of [H-3]-DA from stri
atal slices was attenuated by tetrodotoxin (TTX), MgSO4, dizocilpine,
ketamine, 6,7-dinitroquinoxaline-2,3-dione (DNQX), or carbetapentane.
4. Release of PHI-DA was attenuated by verapamil, omega-conotoxin GVIA
and dantrolene. 5. Nomifensin inhibited the ischaemia-induced release
of [H-3]-DA. 6. Omission of Ca2+ from incubation media potentiated is
chaemia-evoked [H-3]-DA release. The inhibitory effect of nomifensin w
as potentiated in Ca2+-free incubation media. 7. These results suggest
that ischaemia induces release of [H-3]-DA by dual mechanisms; one is
Ca2+-dependent exocytosis and the other is reversal of transporter.