Heuillet E, Ménager J, Fardin V, Flamand O, Bock M, Garret C, Crespo A, Fallourd A M, Doble A
Biology Department, Centre de Recherche de Vitry-Alfortville, Rhône-Poulenc Rorer, Vitry-sur-Seine, France.
J Neurochem. 1993 Mar;60(3):868-76. doi: 10.1111/j.1471-4159.1993.tb03231.x.
The human NK1 tachykinin receptor in the astrocytoma cell line U 373 MG was characterized using selective agonists and antagonists described for this receptor in the rat. Specific [3H]substance P binding sites were present on cell homogenates, whereas [3H]neurokinin A or [3H]-senktide binding sites were absent. The binding was saturable and reversible. The binding of [3H]substance P was inhibited by very low concentrations of [L-Pro9]substance P and [Sar9,Met(O2)11]substance P; septide was approximately 1,000-fold less potent. The most potent peptide antagonist was trans-4-hydroxy-1-(1H-indol-3-ylcarbonyl)-L-prolyl-N-methyl-N-(phe nylmethyl)-L- tyrosineamide. The rank order of potency for the nonpeptide antagonists was (S,S)-CP 96,345 > (+/-)-CP 96,345 > (+/-)-2-chlorobenzylquinuclidinone > (R,R)-CP 96,345 > RP 67580 > RP 68651. In [3H]-inositol-labeled cells, substance P stimulated phosphatidylinositol turnover. A good correlation was found when the abilities of NK1 receptor agonists for stimulating inositol phosphate production and for inhibiting [3H]substance P binding were compared. Similarly, the binding and functional assays were well correlated for the antagonists. As a result of its high sensitivity and selectivity, the U 373 MG cell line thus appears an excellent tool for investigating the pharmacology of the human NK1 receptor.
利用针对大鼠该受体描述的选择性激动剂和拮抗剂，对星形细胞瘤细胞系U 373 MG中的人NK1速激肽受体进行了表征。细胞匀浆中存在特异性的[3H]P物质结合位点，而不存在[3H]神经激肽A或[3H] - 速激肽结合位点。该结合是可饱和且可逆的。极低浓度的[L - Pro9]P物质和[Sar9,Met(O2)11]P物质可抑制[3H]P物质的结合；八肽的效力约低1000倍。最有效的肽拮抗剂是反式 - 4 - 羟基 - 1 - (1H - 吲哚 - 3 - 基羰基) - L - 脯氨酰 - N - 甲基 - N - (苯基甲基) - L - 酪氨酸酰胺。非肽拮抗剂的效力排序为(S,S) - CP 96,345 > (+/-) - CP 96,345 > (+/-) - 2 - 氯苄基奎宁环酮 > (R,R) - CP 96,345 > RP 67580 > RP 68651。在[3H] - 肌醇标记的细胞中，P物质刺激磷脂酰肌醇周转。比较NK1受体激动剂刺激肌醇磷酸生成和抑制[3H]P物质结合的能力时，发现两者具有良好的相关性。同样，拮抗剂的结合和功能测定也具有良好的相关性。由于其高灵敏度和选择性，U 373 MG细胞系因此似乎是研究人NK1受体药理学的极佳工具。
