Aakerlund L, Gether U, Fuhlendorff J, Schwartz T W, Thastrup O
University Department of Clinical Chemistry's Rigshospitalet, Copenhagen, Denmark.
FEBS Lett. 1990 Jan 15;260(1):73-8. doi: 10.1016/0014-5793(90)80069-u.
Two types of binding sites have previously been described for neuropeptide Y (NPY), called Y1 and Y2 receptors. The intracellular events following Y1 receptor activation was studied in the human neuroblastoma cell line SK-N-MC. Both NPY and the specific Y1 receptor ligand, [Leu31,Pro34]-NPY, caused a rapid and transient increase in the concentration of free calcium in the cytoplasm as measured by the fluorescent probe, Fura-2. The effect of both peptides was independent of extracellular calcium as addition of EGTA or manganese neither changed the size nor the shape of the calcium response. The calcium response to NPY was abolished by pretreatment with thapsigargin, which can selectively deplete a calcium store in the endoplasmic reticulum. Y1 receptor stimulation, by both NPY and [Leu31,Pro34]NPY, also inhibited the forskolin-stimulated cAMP production with an EC50 of 3.5 nM. There was a close relation between the receptor binding and the cellular effects as half-maximal displacement of [125I-Tyr36]monoiodoNPY from the receptor was obtained with 2.1 nM NPY. The Y2-specific ligand NPY(16-36)peptide had no effect on either intracellular calcium or cAMP levels in the SK-N-MC cells. It is concluded that Y1 receptor stimulation is associated with both mobilization of intracellular calcium and inhibition of adenylate cyclase activity.
先前已描述了神经肽Y（NPY）的两种结合位点，称为Y1和Y2受体。在人神经母细胞瘤细胞系SK-N-MC中研究了Y1受体激活后的细胞内事件。通过荧光探针Fura-2测量，NPY和特异性Y1受体配体[Leu31，Pro34]-NPY均导致细胞质中游离钙浓度迅速且短暂地升高。两种肽的作用均与细胞外钙无关，因为添加EGTA或锰既未改变钙反应的大小也未改变其形状。用毒胡萝卜素预处理可消除对NPY的钙反应，毒胡萝卜素可选择性耗尽内质网中的钙储存。NPY和[Leu31，Pro34]NPY对Y1受体的刺激也抑制了福斯高林刺激的cAMP产生，EC50为3.5 nM。受体结合与细胞效应之间存在密切关系，用2.1 nM NPY可使[125I-Tyr36]单碘NPY从受体上半最大位移。Y2特异性配体NPY(16-36)肽对SK-N-MC细胞中的细胞内钙或cAMP水平均无影响。结论是Y1受体刺激与细胞内钙的动员和腺苷酸环化酶活性的抑制均有关。
