[酸中毒对大鼠脑突触体膜电位及钙转运的影响]

[Effect of acidosis on membrane potential and calcium transport in rat brain synaptosomes].

作者信息

Fedorovich S V, Aksentsev S L, Lyskova T I, Kaler G V, Fedulov A S, Konev S V

出版信息

Biofizika. 1997 Mar-Apr;42(2):412-6.

Abstract

The influence of acidosis on the transmembrane potential, sodium pump and membranous systems of calcium transport was studied on isolated presynaptic nerve terminals (synaptosomes) from rat brain. It is established that acidic shift causes a decrease of membrane potential, a large inhibition of the sodium pump (by three times at pH 6.0). All the systems controlling both inward- and outward-directed calcium fluxes are partially blocked by low pH. At pH 6.0 the basal influx and calcium pump are reduced two-fold while the voltage-sensitive calcium channels and Na+/Ca2+ exchanger are inhibited by three and four to five times, respectively. We have no found any evidence of acidosis-induced net flux of calcium directed inwards.

摘要

在大鼠脑分离的突触前神经末梢（突触体）上研究了酸中毒对跨膜电位、钠泵和钙转运膜系统的影响。已确定酸性转变会导致膜电位降低，钠泵受到极大抑制（在pH 6.0时抑制三倍）。所有控制内向和外向钙通量的系统都被低pH值部分阻断。在pH 6.0时，基础内流和钙泵减少两倍，而电压敏感性钙通道和Na+/Ca2+交换器分别被抑制三到四到五倍。我们没有发现酸中毒诱导钙向内净通量的任何证据。