Lewis R E, Childers S R, Phillips M I
Brain Res. 1985 Nov 4;346(2):263-72. doi: 10.1016/0006-8993(85)90859-5.
Kinins bind to specific, high affinity recognition sites in rat brain cell culture. Studies in these cultures minimize non-specific binding and degradation of the ligand. Binding of [125I]Tyr-bradykinin to intact cultured brain cells from neonatal rats was time- and pH-dependent. Scatchard analysis of saturation experiments yielded two affinity components with dissociation constant and maximum binding site concentration averaging 1 nM and 100 fmol/mg protein, and 16 nM and 1000 fmol/mg protein, respectively. The binding sites were specific for kinins and kinin analogues, and the order of potency in competing for [125I]Tyr-bradykinin binding was Lys-bradykinin greater than bradykinin greater than Tyr-bradykinin greater than Tyr8-bradykinin much much greater than Des-Arg9-bradykinin. Monovalent and divalent cations inhibited kinin binding. Comparison of competition curves performed in glial-enriched vs neuron-enriched cultures suggested that the kinin binding sites resided primarily on neurons. These data enhance the existing evidence suggesting kinins as neurotransmitters or neuromodulators.
激肽可与大鼠脑细胞培养物中的特异性高亲和力识别位点结合。在这些培养物中的研究将配体的非特异性结合和降解降至最低。[125I]酪氨酸缓激肽与新生大鼠完整培养脑细胞的结合具有时间和pH依赖性。饱和实验的Scatchard分析产生了两个亲和力成分，解离常数和最大结合位点浓度分别平均为1 nM和100 fmol/mg蛋白质，以及16 nM和1000 fmol/mg蛋白质。这些结合位点对激肽和激肽类似物具有特异性，竞争[125I]酪氨酸缓激肽结合的效力顺序为：赖氨酰缓激肽大于缓激肽大于酪氨酸缓激肽大于酪氨酸8-缓激肽远大于去精氨酸9-缓激肽。单价和二价阳离子抑制激肽结合。在富含胶质细胞与富含神经元的培养物中进行的竞争曲线比较表明，激肽结合位点主要位于神经元上。这些数据增强了现有证据，表明激肽可作为神经递质或神经调节剂。
