PDF(Pubmed)
Abstract：
Retinal sensitivity to a variety of artificial sweeteners was tested by monitoring changes in internal free calcium in isolated retinal neurons using Fluo3. Several ligands, including aspartame and saccharin elevated internal free calcium. The effects of these ligands were mediated by both ligand-gated membrane channels and G-protein coupled receptors. We explored the receptors responsible for this phenomenon. Surprisingly, mRNA for subunits of the sweet taste receptor dimer (T1R2 and T1R3) were found in retina. Interestingly, knockdown of T1R2 reduced the response to saccharin but not aspartame. But TRPV1 channel antagonists suppressed the responses to aspartame. The results indicate that artificial sweeteners can increase internal free calcium in the retinal neurons through multiple pathways. Furthermore, aspartame reduced the b-wave, but not the a-wave, of the electroretinogram, indicating disruption of communication between photoreceptors and second order neurons.
摘要：
通过使用Fluo3监测分离的视网膜神经元中内部游离钙的变化来测试视网膜对多种人工甜味剂的敏感性。几个配体，包括阿斯巴甜和糖精在内的体内游离钙升高。这些配体的作用是由配体门控膜通道和G蛋白偶联受体介导的。我们探索了导致这种现象的受体。令人惊讶的是,在视网膜中发现了甜味受体二聚体（T1R2和T1R3）亚基的mRNA。有趣的是,T1R2的敲除降低了对糖精的反应，但对阿斯巴甜没有影响。但是TRPV1通道拮抗剂抑制了对阿斯巴甜的反应。结果表明，人工甜味剂可以通过多种途径增加视网膜神经元的内部游离钙。此外，阿斯巴甜减少了b波，但不是a波，视网膜电图，表明光感受器和二阶神经元之间的通讯中断。
