Cubillán Lisbeth, Obregón Francisco, Lima Lucimey
Laboratorio de Neuroquímica, Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas, Venezuela.
Adv Exp Med Biol. 2009;643:225-31. doi: 10.1007/978-0-387-75681-3_23.
Taurine stimulates outgrowth of goldfish retinal explants in a concentration- and time-dependent manner, an effect related to calcium movement and protein phosphorylation. Since taurine is an osmoregulator in the central nervous system, and osmolality might influence regeneration, the purpose of this work was to evaluate the possible effect of hypo-osmolality on basal outgrowth and on the trophic action of the amino acid. Accordingly, goldfish retinal explants obtained after crushing the optic nerve were cultured in iso- and hypo-osmotic medium, the latter achieved by diluting the medium 10% 24 and 72 h after plating. The length and density of the neurites, measured after 5 days in culture, were significantly lower in the hypo- than in the iso-osmotic medium. Taurine stimulated the outgrowth under both conditions, but the percentage of increase was greater in iso-osmotic medium. Taurine concentration, determined by HPLC, did not significantly change in explants. Co-administration of beta-alanine and taurine impaired the trophic effect of taurine to a greater extent in the iso- than in hypo-osmotic medium, indicating a possible differential interaction with the taurine transporter which could be altered by osmotic stress. The exact mechanism of outgrowth regulation by hypotonicity requires further clarification, taking into considering possible modification of the taurine transporter.
牛磺酸以浓度和时间依赖性方式刺激金鱼视网膜外植体的生长，这种效应与钙转运和蛋白质磷酸化有关。由于牛磺酸是中枢神经系统中的一种渗透压调节剂，且渗透压可能影响再生，因此本研究的目的是评估低渗对基础生长以及该氨基酸营养作用的可能影响。相应地，将视神经挤压后获得的金鱼视网膜外植体在等渗和低渗培养基中培养，低渗培养基是通过在接种后24小时和72小时将培养基稀释10%来实现的。培养5天后测量的神经突长度和密度，在低渗培养基中显著低于等渗培养基。在两种条件下牛磺酸均刺激了生长，但在等渗培养基中增加的百分比更大。通过高效液相色谱法测定，外植体中的牛磺酸浓度没有显著变化。在等渗培养基中，β-丙氨酸和牛磺酸共同给药比在低渗培养基中更大程度地损害了牛磺酸的营养作用，这表明与牛磺酸转运体可能存在差异相互作用，而这种相互作用可能会因渗透压应激而改变。考虑到牛磺酸转运体可能的修饰，低渗调节生长的确切机制需要进一步阐明。
