Role of calcium in synaptosomal substrate oxidation.
Role of calcium in synaptosomal substrate oxidation.
复制标题
钙在突触体底物氧化中的作用。
DOI：
10.1016/0003-9861(88)90301-3
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发表时间：
1988
影响因子：
3.9
通讯作者：
Rashed,HM
中科院分区：
文献类型：
--
作者：
Patel,TB;Sambasivarao,D;Rashed,HM
研究了钙离子存在和不存在时，藜芦碱介导的去极化对大鼠脑突触体呼吸的影响。采用三种不同的预处理的突触体，试图耗尽内源性底物的呼吸进行研究。首先，在不存在任何底物的情况下，在含有或不含钙的培养基中预孵育突触体10分钟。第二，突触体预孵育15或60分钟的时间在存在和不存在的钙，和孵育介质的变化，通过离心和重新悬浮的突触体在各自的媒体。无论先前处理如何，仅当孵育培养基中存在钙时，才观察到藜芦碱（100 μm）引起去极化期间的最大呼吸刺激（400-600%）。在孵育中进行的情况下，钙，藜芦碱除了适度刺激（10和15分钟预孵育突触体）或不影响（60分钟预孵育突触体）的呼吸速率。然而，当钙被添加回这些孵育物中时，在藜芦定存在下的呼吸速率被刺激了五到六倍。同样，只有当突触体在充满钙的培养基中孵育时，[1- 14 C]-和[2- 14 C]-丙酮酸的14 CO2产生率才被藜芦碱增加。这些数据表明，钙起着强制性的作用，在去极化引起的刺激突触体氧化过程。
The effect of veratridine-mediated depolarization on rat brain synaptosomal respiration in the presence and absence of calcium was investigated. Studies on respiration were performed employing three different pretreatments of the synaptosomes which attempted to deplete endogenous substrates. First, synaptosomes were preincubated for 10 min in the absence of any substrates in medium either containing or devoid of calcium. Second, synaptosomes were preincubated for either 15 or 60-min periods in the presence and absence of calcium, and the incubation medium was changed by centrifugation and resuspension of synaptosomes in their respective media. Irrespective of the prior treatment, maximal stimulation of respiration (400–600%) during veratridine (100 μm) elicited depolarization was observed only when calcium was present in the incubation media. In incubations performed in the absence of calcium, veratridine addition either modestly stimulated (10- and 15-min preincubated synaptosomes) or did not affect (60-min preincubated synaptosomes) the rate of respiration. However, when calcium was added back to these incubations the rate of respiration in the presence of veratridine was stimulated by five- to six-fold. Similarly, the rates of14CO2production from [1-14C]- and [2-14C]pyruvate were increased by veratridine only when synaptosomes were incubated in calcium-replete medium. These data indicate that calcium plays an obligatory role in depolarization-elicited stimulation of synaptosomal oxidative processes.