Izenwasser S, Rosenberger J G, Cox B M
Department of Pharmacology, Uniformed Services University, Bethesda, MD 20814-4799.
Life Sci. 1992;50(8):541-7. doi: 10.1016/0024-3205(92)90365-v.
Cocaine inhibits both [3H]dopamine and [3H]serotonin uptake in rat striatum and nucleus accumbens. In a chopped tissue slice preparation, the inhibition curve for [3H]dopamine uptake is biphasic, suggesting two components of uptake, whereas the curve for [3H]serotonin uptake is steep and apparently monophasic. In synaptosomal preparations, both curves are monophasic. Monensin, a sodium ionophore, inhibits uptake but does not change the shape of the cocaine inhibition curve in synaptosomes, suggesting that the biphasic inhibition curves in slices are not likely due to differential sodium gradients across the slices. In tissue slices, only the component which is more sensitive to inhibition by cocaine and related drugs is inhibitable by nicotine. This suggests that the two components of dopamine uptake in tissue slices may be differentially regulated.
可卡因可抑制大鼠纹状体和伏隔核中[3H]多巴胺和[3H]5-羟色胺的摄取。在切碎组织切片制备中，[3H]多巴胺摄取的抑制曲线呈双相，提示存在两种摄取成分，而[3H]5-羟色胺摄取的曲线陡峭且明显呈单相。在突触体制备中，两条曲线均为单相。莫能菌素，一种钠离子载体，可抑制摄取，但不改变突触体中可卡因抑制曲线的形状，提示切片中的双相抑制曲线不太可能是由于切片两侧钠梯度差异所致。在组织切片中，只有对可卡因及相关药物抑制更敏感的成分可被尼古丁抑制。这表明组织切片中多巴胺摄取的两种成分可能受到不同调节。
