Laboratorio de Neuroquímica, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
J Biomed Sci. 2010 Aug 24;17 Suppl 1(Suppl 1):S13. doi: 10.1186/1423-0127-17-S1-S13.
Taurine and zinc exert neurotrophic effects in the central nervous system. Current studies demonstrate that Na+/Cl- dependent neurotransmitter transporters, similar to that of taurine, are modulated by micromolar concentrations of zinc. This study examined the effect of zinc sulfate ex vivo on [3H]taurine transport in goldfish retina.
Isolated cells were incubated in Ringer with zinc (0.1-100 microM). Taurine transport was done with 50 nM [3H]taurine or by isotopic dilution with taurine (0.001-1 mM) and 50 nM [3H]taurine.
Zinc reduced the capacity of taurine transport without changes in affinity, and caused a noncompetitive inhibition of high affinity taurine transport, with an EC50= 0.072 microM. The mechanism by which zinc affects taurine transport is unknown at the present.
There may be a binding site of zinc in the transporter that affects union or translocation of taurine, or possibly the formation of taurine-zinc complexes, rather than free zinc, could affect the operation of the transporter.
牛磺酸和锌在中枢神经系统中发挥神经营养作用。目前的研究表明，类似于牛磺酸的 Na+/Cl- 依赖性神经递质转运体，其功能可被微摩尔浓度的锌调节。本研究检测了硫酸锌在体外对金鱼视网膜[3H]牛磺酸转运的影响。
将分离的细胞在含锌（0.1-100 μM）的 Ringer 液中孵育。用 50 nM [3H]牛磺酸或用牛磺酸（0.001-1 mM）和 50 nM [3H]牛磺酸进行同位素稀释进行牛磺酸转运。
锌降低了牛磺酸转运的能力，而对亲和力没有影响，并导致高亲和力牛磺酸转运的非竞争性抑制，EC50=0.072 μM。目前尚不清楚锌影响牛磺酸转运的机制。
转运体中可能存在锌的结合位点，影响牛磺酸的结合或易位，或者可能是牛磺酸-锌复合物的形成，而不是游离锌，影响转运体的运作。
