Palma C, Goso C, Manzini S
Menarini Ricerche Sud, Pharmacology Department, Pomezia, Roma, Italy.
Neurosci Lett. 1994 Apr 25;171(1-2):221-4. doi: 10.1016/0304-3940(94)90644-0.
In a human astrocytoma cell line U373 MG, the activation of the neurokinin 1 (NK1) receptor by substance P (SP) increase, in a concentration-related manner (1 nM to 10 microM), the basal release of interleukin-6 (IL-6) as assayed by an ELISA method, in cell supernatants after 18 h of incubation. Septide, a selective NK1 receptor agonist, is equipotent to SP in inducing the IL-6 release showing similar Emax (2644 +/- 285 and 2830 +/- 271 pg/ml) and EC50 (15.6 +/- 3.6 and 13.8 +/- 3.2 nM). However, in binding assays on intact cells, septide was an about 50-fold weaker displacer of the binding of [3H][Sar9,Met(O2)11]SP than SP (Ki's were 0.28 +/- 0.1 nM and 14.2 +/- 5.0 nM for SP and septide, respectively). NK2- and NK3-selective agonists (up to 1 microM) had no binding or functional effect. Highly selective non-peptide (CP96,345) or peptide (GR82,334) NK1 receptor antagonists were more effective in antagonizing septide-(IC50's 0.2 +/- 0.06 nM and 70 +/- 18 nM) than SP-(IC50's 6.7 +/- 1.3 nM and 1.95 +/- 0.4 microM) induced IL-6 secretion. These data support the existence, also in human U373 MG cells, of a septide-sensitive NK1 receptor subtype(s) and/or epitope(s) blocked with high affinity by NK1 antagonist.
在人星形细胞瘤细胞系U373 MG中，P物质（SP）对神经激肽1（NK1）受体的激活以浓度相关方式（1 nM至10 μM）增加了白细胞介素-6（IL-6）的基础释放，这是通过酶联免疫吸附测定法（ELISA）在孵育18小时后的细胞上清液中检测到的。Septide是一种选择性NK1受体激动剂，在诱导IL-6释放方面与SP等效，显示出相似的最大效应（Emax）（分别为2644±285和2830±271 pg/ml）和半数有效浓度（EC50）（分别为15.6±3.6和13.8±3.2 nM）。然而，在完整细胞的结合试验中，Septide对[3H][Sar9,Met(O2)11]SP结合的置换能力比SP弱约50倍（SP和Septide的解离常数Ki分别为0.28±0.1 nM和14.2±5.0 nM）。NK2和NK3选择性激动剂（浓度高达1 μM）没有结合作用或功能效应。高选择性非肽（CP96,345）或肽（GR82,334）NK1受体拮抗剂在拮抗Septide诱导的IL-6分泌（IC50分别为0.2±0.06 nM和70±18 nM）方面比拮抗SP诱导的IL-6分泌（IC50分别为6.7±1.3 nM和1.95±0.4 μM）更有效。这些数据支持在人U373 MG细胞中也存在对Septide敏感的NK1受体亚型和/或表位，它们被NK1拮抗剂以高亲和力阻断。
