Demonstration of competition between endogenous dopamine and [11C]raclopride binding in in vitro brain slices using a dynamic autoradiography technique
Demonstration of competition between endogenous dopamine and [11C]raclopride binding in in vitro brain slices using a dynamic autoradiography technique
复制标题
使用动态放射自显影技术演示体外脑切片中内源性多巴胺和[11C]雷氯必利结合之间的竞争
作者：
Toru Sasaki;K. Ishiwata;T. Murata;M. Senda
To elucidate the mechanism of in vivo binding competition between radioligand and endogenously released transmitter, we examined the influence of depolarization‐induced dopamine (DA) release on [11C]raclopride‐specific binding to D2 receptors in slices of living brain tissues using dynamic positron autoradiography. Rat brain slices were incubated in a chamber with [11C]raclopride in oxygenated medium at 34°C for 150 min. Two‐dimensional images of radioactivity in the slices were recorded on a storage phosphor screen and dynamic changes were measured. When the brain slices were exposed to the depolarization agents (25 mM K+, 50 mM K+, and 20 μM veratridine), the percentage inhibition of striatal [11C]raclopride‐specific binding was 22 ± 4%, 44 ± 8% and 54 ± 7% of the control, respectively. The percentage inhibition of [11C]raclopride‐specific binding during each depolarization treatment agreed proportionally with the amount of DA released into the medium. However, preexposure of brain slices to the same depolarization treatment (50 mM K+) did not affect the [11C]raclopride‐specific binding, suggesting that the reduction in receptor density and/or affinity was not involved in the decrease of [11C]raclopride‐specific binding. [11C]Raclopride‐specific binding decreased dose‐dependently in the presence of exogenously added DA (range 0.005–3mM). The synaptic DA concentration during each depolarization treatment estimated using three different methods.
未使用抗精神病药的精神分裂症患者的 D2 多巴胺受体。
影响因子：
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作者：
Farde,L;Wiesel,FA;Stone-Elander,S;Halldin,C;Nordström,AL;Hall,H;Sedvall,G
通讯作者：
Sedvall,G