用放射配体受体结合法测定表明:克塞平对多巴胺D_1受体的亲和力较异戊塞平高近20倍。两药对其它各受体的亲和力差別不大。慢性给药后,异戊塞平和克塞平均能使大鼠脑皮层5-HT_2受体的密度显著下降,而亲和力变化不明显。这种下调5-HT_2受体的作用发生在给异戊塞平后1～2周之间,给克塞平后的2～3周之间。慢性给药3周,异戊塞平和克塞平均未使大鼠脑皮层的β受体密度及亲和力产生显著变化。 Radioligand receptor binding assay showed that the affinity of paclitaxel for dopamine D_1 receptor was 20-fold higher than that of isoprenaline. The affinity of the two drugs for other receptors is not very different. After chronic administration, isopenten and paclitaxel could obviously decrease the density of 5-HT 2 receptor in cerebral cortex of rats, but the change of affinity was insignificant. This down-regulation of the 5-HT2 receptor takes place between 1 and 2 weeks after isopenterpine and between 2 and 3 weeks after paclitaxel. After 3 weeks of chronic administration, isopenten / paclitaxel did not significantly change the β receptor density and affinity of the rat cortex.