Basal phosphatidylinositol turnover controls aortic Na+/K+ ATPase activity.
Basal phosphatidylinositol turnover controls aortic Na+/K+ ATPase activity.
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基础磷脂酰肌醇周转控制主动脉 Na /K ATP 酶活性。
DOI：
10.1172/jci112330
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Martin,DB
中科院分区：
文献类型：
--
作者：
Simmons,DA;Kern,EF;Winegrad,AI;Martin,DB
为了确定在稳态条件下培养的静息兔主动脉内膜中，基础磷酸肌醇转换是否在代谢调节中发挥作用，我们利用剥夺细胞外肌醇作为抑制限制性位点基础磷脂酰肌醇（PI）合成和快速基础转换消耗小磷酸肌醇池的潜在手段。正常血浆水平的中等肌肌醇需要防止基础从头PI合成的特定成分的抑制，这是证明离散快速翻转[1,3- 14c]甘油标记PI池所必需的。用[1-14C]花生四烯酸（AA）标记离散PI池也需要中等肌醇。当用甘油或AA标记时，这个PI池的快速基础周转不是由于其用于多磷酸肌醇的形成，而是反映了基础PI水解。用中等脱脂白蛋白消耗内源性游离AA选择性地抑制基础从头合成PI的成分，该成分补充了快速周转的PI池。主动脉内膜-中膜正常静息能量利用的一个组成部分也特别需要正常血浆水平的中等肌醇和游离AA池；吲哚美辛、去甲双氢愈创木酸或无Ca2+培养基均不改变其强度。这种能量利用主要来自Na+/K+ atp酶活性（抑制性的氧消耗），在无Ca2+的培养基中，剥夺中肌醇或游离AA对静息Na+/K+ atp酶活性的抑制程度相似（60%,52%）。在主动脉内膜-中膜中，基础PI转换控制了静息Na+/K+ atp酶活性的主要部分。
To determine whether basal phosphoinositide turnover plays a role in metabolic regulation in resting rabbit aortic intima-media incubated under steady state conditions, we used deprivation of extracellular myo-inositol as a potential means of inhibiting basal phosphatidylinositol (PI) synthesis at restricted sites and of depleting small phosphoinositide pools with a rapid basal turnover. Medium myo-inositol in a normal plasma level was required to prevent inhibition of a specific component of basal de novo PI synthesis that is necessary to demonstrate a discrete rapidly turning-over [1,3-14C]glycerol-labeled PI pool. Medium myo-inositol was also required to label the discrete PI pool with [1-14C]arachidonic acid (AA). The rapid basal turnover of this PI pool, when labeled with glycerol or AA, was not attributable to its utilization for polyphosphoinositide formation, and it seems to reflect basal PI hydrolysis. Depleting endogenous free AA with medium defatted albumin selectively inhibits the component of basal de novo PI synthesis that replenishes the rapidly turning-over PI pool. A component of normal resting energy utilization in aortic intima-media also specifically requires medium myo-inositol in a normal plasma level and a free AA pool; its magnitude is unaltered by indomethacin, nordihydroguaiaretic acid, or Ca2+-free medium. This energy utilization results primarily from Na+/K+ ATPase activity (ouabain-inhibitable O2 consumption), and in Ca2+-free medium deprivation of medium myo-inositol or of free AA inhibits resting Na+/K+ ATPase activity to a similar degree (60%, 52%). In aortic intima-media basal PI turnover controls a major fraction of resting Na+/K+ ATPase activity.