Effects of exogenous inositol hexakisphosphate (InsP6) on the levels of InsP6 and of inositol trisphosphate (InsP3) in malignant cells, tissues and biological fluids
Effects of exogenous inositol hexakisphosphate (InsP6) on the levels of InsP6 and of inositol trisphosphate (InsP3) in malignant cells, tissues and biological fluids
复制标题
DOI：
10.1016/s0024-3205(02)01927-6
复制
发表时间：
2002-08-16
期刊：
影响因子：
6.1
通讯作者：
Shamsuddin, AM
中科院分区：
文献类型：
--
作者：
Grases, F;Simonet, BM;Shamsuddin, AM
InsP（6）在谷类和豆类中含量丰富。InsP（6）和低级肌醇磷酸，特别是InsP（3），参与重要的细胞内过程。此外，InsP（6）还具有显著的保健作用，如抗癌、预防肾结石、降低血清胆固醇等。由于现有的非放射性标记肌醇磷酸测定方法的不灵敏性，人们对天然存在的情况知之甚少，更不用说生物样品中InsP（6）和InsP（3）的浓度了。使用HPLC色谱组分的气相色谱-质谱检测分析，我们报告了未标记的总InsP（3）和InsP（6）的测量（a），因为它们存在于细胞培养物、组织和血浆中，以及（B）它们的变化取决于外源InsP（6）的存在。当大鼠喂食InsP（6）不可检测的纯化饮食（AIN-76 A）时，脑中InsP（6）的水平为3.35 +/- 0.57（SE）pmol.kg（-1），血浆中InsP（6）的水平为0.023 +/- 0.008（SE）μ mol.l（-1）。InsP（6）在饮食中的存在显著影响其在脑和血浆中的水平。当给大鼠提供足够InsP（6）的饮食时，（AIN-76 A +1%InsP（6）），InsP（6）在脑组织中的水平高约100倍（36.8 +/- 1.8（SE））（0.29 +/- 0.02（SE））; InsP（6）浓度是血浆（0.033 +/- 0.012（SE））和脑（4.21 +/- 0.55（SE））中总InsP（3）浓度的8.5倍。当动物被给予InsP（6）-贫乏的饮食（仅AIN-76 A）时，脑组织和血浆中的InsP（6）含量降低90%（p < 0.001）;然而，总InsP（3）水平没有变化。在未受刺激的恶性肿瘤细胞（MDA-MB 231和K562）中，InsP（6）含量分别为16.2 ± 9.1（SE）μ mol·kg（-1）和15.6 ± 2.7（SE）μ mol·kg（-1）。这些值约为InsP（3）的3倍（MDA-MB 231和K562细胞分别为4.8 ± 0.5 μ mol. kg（-1）和6.9 ± 0.1（SE）））。用InSP 6处理恶性细胞导致细胞内总InsP（3）浓度增加2倍（MDA-MB 231和K562细胞分别为9.5 ± 1.3（SE）和10.8 ± 1.0（SE）μ mol. kg（-1），p < 0.05），InsP（6）水平无变化。这些结果表明，外源性InsP（6）直接影响正常大鼠血浆和脑内InsP（3）的生理水平，而不影响总InsP（3）水平。虽然InsP（6）处理后在人恶性细胞系中未观察到InsP（6）浓度的类似波动，但清楚地观察到细胞内总InsP（3）水平的增加。(C)2002年爱思唯尔科技有限公司All rights reserved.
InsP(6) is abundant in cereals and legumes. InsP(6) and lower inositol phosphates, in particular InsP(3), participate in important intracellular processes. In addition, InsP(6) possess significant health benefits, such as anti-cancer effect, kidney stones prevention, lowering serum cholesterol. Because of the insensitivity of existing methods for determination of non-radiolabeled inositol phosphates, little is known about the natural occurrence, much less on the concentrations of InsP(6) and InsP(3) in biological samples. Using gas chromatography-mass detection analysis of HPLC chromatographic fractions, we report a measurement of unlabeled total InsP(3) and InsP(6) (a) as they occur within cells culture, tissues, and plasma, and (b) their changes depending on the presence of exogenous InsP(6). When rats were fed on a purified diet in which InsP(6) was undetectable (AIN-76A) the levels of InsP(6) in brain were 3.35 +/- 0.57 (SE) pmol.kg(-1) and in plasma 0.023 +/- 0.008 (SE) mumol.l(-1). The presence of InsP(6) in diet dramatically influenced its levels in brain and in plasma. When rats were given an InsP(6)-sufficient diet (AIN-76A + 1% InsP(6)), the levels of InsP(6) were about 100-fold higher in brain tissues (36.8 +/- 1.8 (SE)) than in plasma (0.29 +/- 0.02 (SE)); InsP(6) concentrations were 8.5-fold higher than total InsP(3) concentrations in either plasma (0.033 +/- 0.012 (SE)) and brain (4.21 +/- 0.55 (SE)). When animals were given an InsP(6)-poor diet (AIN-76A only), there was a 90% decrease in InsP(6) content in both brain tissue and plasma (p < 0.001); however, there was no change in the level of total InsP(3). In non-stimulated malignant cells (MDA-MB 231 and K562) the InsP(6) contents were 16.2 ± 9.1 (SE) μmol.kg(-1) for MDA-MB 231 cells and 15.6 ± 2.7 (SE) for K 562 cells. These values were around 3-fold higher than those of InsP(3) (4.8 ± 0.5 μmol.kg(-1) and 6.9 ± 0.1 (SE) for MDA-MB 231 and K562 cells respectively). Treatment of malignant cells with InSP6 resulted in a 2-fold increase in the intracellular concentrations of total InsP(3) (9.5 ± 1.3 (SE) and 10.8 ± 1.0 (SE) μmol.kg(-1) for MDA-MB 231 and K562 cells, respectively, p < 0.05), without changes in InsP(6) levels. These results indicate that exogenous InsP(6) directly affects its physiological levels in plasma and brain of normal rats without changes on the total InsP(3) levels. Although a similar fluctuation of InsP(6) concentration was not seen in human malignant cell lines following InsP(6) treatment, an increased intracellular level of total InsP(3) was clearly observed. (C) 2002 Elsevier Science Inc. All rights reserved.