Influences of cholecystokinin octapeptide on phosphoinositide turnover in neonatal-rat brain cells.
Influences of cholecystokinin octapeptide on phosphoinositide turnover in neonatal-rat brain cells.
复制标题
胆囊收缩素八肽对新生大鼠脑细胞磷酸肌醇周转的影响。
DOI：
10.1042/bj2850847
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Han,JS
中科院分区：
文献类型：
--
作者：
Zhang,LJ;Lu,XY;Han,JS
八肽胆囊收缩素（CCK-8）在胰腺腺泡、神经母细胞瘤细胞和人胚胎细胞系中与磷脂酰肌醇转换有关。然而，人们对它与大脑中磷脂酰肌醇分解的联系知之甚少。取1-2日龄新生大鼠的脑（小脑除外），酶促分离成单细胞。通过与肌-[3 H]肌醇孵育3小时预标记完整细胞，然后在10 mM-LiCl存在下用激动剂刺激。1 mM卡巴胆碱诱导脑细胞中InsP 3标记的增加（在30 min达到峰值，然后逐渐降低），以及InsP随时间的静态积累，而InsP 2的标记基本保持不变。10 nM-CCK-8在刺激磷酸肌醇周转中获得了非常相似的时间响应曲线。孵育脑细胞的剂量-反应曲线显示，当CCK-8的浓度从0.1增加到10 nM时，InsP 3的形成增加。CCK-8浓度进一步增加至100-1000 nM导致InsP 3形成逐渐减少。InsP和InsP 2水平保持相对稳定。在1-10 nM浓度范围内，CCK-A拮抗剂Devazepide剂量依赖性地抑制10 nM-CCK-8刺激的InsP 3产生;当浓度进一步增加至100-1000 nM时，该效应下降。相比之下，CCK-B拮抗剂L365，260在高于0.1 nM的浓度下，即在1-1000 nM的范围内，显示出对InsP 3产生的持续抑制。结果提供的证据表明，CCK-8刺激营业额的磷脂酰肌醇和增加InsP 3标记在分离的大鼠脑细胞，其中CCK-A和CCK-B受体似乎参与。
Cholecystokinin octapeptide (CCK-8) has been shown to be coupled to phosphoinositide turnover in pancreatic acini as well as in a kind of neuroblastoma cell and a human embryonic cell line. Little is known, however, about its link with phosphatidylinositol breakdown in the brain. The brains (minus cerebella) from 1-2-day-old neonatal rats were enzymically dissociated into single cells. The intact cells were prelabelled by incubation with myo-[3H]inositol for 3 h, and were then stimulated with agonists in the presence of 10 mM-LiCl. Carbachol at 1 mM induced an increase in InsP3 labelling in brain cells (peak at 30 min, and then a gradual decrease), and a static accumulation of InsP with time, whereas the labelling of InsP2 remained essentially unchanged. A very similar time-response curve was obtained for 10 nM-CCK-8 in stimulating phosphoinositide turnover. The dose-response curve for incubated brain cells revealed that the formation of InsP3 increased when the concentration of CCK-8 was increased from 0.1 to 10 nM. A further increase in CCK-8 concentration to 100-1000 nM resulted in a gradual decrease in InsP3 formation. InsP and InsP2 levels stayed relatively stable. The production of InsP3 stimulated by 10 nM-CCK-8 was dose-dependently suppressed by the CCK-A antagonist Devazepide in the concentration range 1-10 nM; the effect declined when the concentration was further increased to 100-1000 nM. In contrast, the CCK-B antagonist L365,260 showed a sustained suppression of InsP3 production at concentrations above 0.1 nM, i.e. in the range 1-1000 nM. The results provide evidence that CCK-8 stimulates the turnover of phosphoinositide and increases InsP3 labelling in dissociated neonatal-rat brain cells, in which both CCK-A and CCK-B receptors seem to be involved.