Bettendorff L, Wins P, Schoffeniels E
Laboratory of General and Comparative Biochemistry, University of Liège, Belgium.
Biochem Biophys Res Commun. 1990 Sep 28;171(3):1137-44. doi: 10.1016/0006-291x(90)90803-u.
We examined the effects of thiamine derivatives on ion uptake in rat brain membrane vesicles. Thiamine triphosphate (1 mM) and pyrithiamine (0.1 mM) increase chloride uptake. Preincubation of crude homogenate with thiamine or pyrithiamine increases chloride uptake while oxythiamine has the reverse effect. Thiamine and oxythiamine also affect 22Na+ and 86Rb+ uptake in the same way as for 36Cl- but to a lesser extent. Thiamine-dependent 36Cl- uptake is activated by sodium bicarbonate (10 mM) and partially inhibited by bumetanide (0.1 mM) and 2,4-dinitrophenol (0.1 mM). Preincubation with thiamine increases the thiamine triphosphate content of the vesicles. The hypothesis that TTP is the activator of a particular chloride uptake mechanism is discussed.
我们研究了硫胺素衍生物对大鼠脑膜囊泡中离子摄取的影响。三磷酸硫胺素（1 mM）和吡硫胺（0.1 mM）可增加氯离子摄取。用硫胺素或吡硫胺对粗匀浆进行预孵育可增加氯离子摄取，而氧硫胺素则有相反作用。硫胺素和氧硫胺素对22Na+和86Rb+摄取的影响与对36Cl-的影响相同，但程度较小。依赖硫胺素的36Cl-摄取可被碳酸氢钠（10 mM）激活，并被布美他尼（0.1 mM）和2,4-二硝基苯酚（0.1 mM）部分抑制。用硫胺素预孵育可增加囊泡中三磷酸硫胺素的含量。文中讨论了三磷酸硫胺素是特定氯离子摄取机制激活剂的假说。
