Bauer B, Ehinger B
Brain Res. 1977 Jan 28;120(3):447-57. doi: 10.1016/0006-8993(77)90398-5.
The efflux of [3H]beta-alanine from rabbit retina after intravitreal injection has been studied. The site of uptake of [3H]beta-alanine into retina was checked by autoradiography and was found mainly in the inner plexiform layer and in cells with the position of amacrines and in some ganglion cells. When the preloaded retina was stimulated by light flashes and release of radioactivity increased significantly. Chromatography of the superfusate demonstrated a single radioactive spot which cochromatographed with authentic beta-alanine. The efflux of [3H]beta-alanine was affected by raising the K+ concentration. The rate of efflux was also immediately increased when unlabelled beta-alanine or GABA was added to the superfusion medium. Glycine was much less effective. The present study shows that light stimulation releases [3H]beta-alanine from the retina and that beta-alanine may use the same transport system as GABA. This further supports the suggestion that beta-alanine may act as a "false transmitter" replacing GABA in the retina.
研究了玻璃体内注射[³H]β-丙氨酸后其从兔视网膜的流出情况。通过放射自显影检查了[³H]β-丙氨酸进入视网膜的摄取部位，发现主要位于内网状层以及无长突细胞位置的细胞和一些神经节细胞中。当预先加载放射性的视网膜受到闪光刺激时，放射性释放显著增加。对超滤液进行色谱分析显示有一个单一的放射性斑点，它与纯β-丙氨酸共色谱。提高钾离子浓度会影响[³H]β-丙氨酸的流出。当向超灌流培养基中加入未标记的β-丙氨酸或γ-氨基丁酸时，流出速率也会立即增加。甘氨酸的作用则小得多。本研究表明光刺激会使[³H]β-丙氨酸从视网膜释放，并且β-丙氨酸可能与γ-氨基丁酸使用相同的转运系统。这进一步支持了β-丙氨酸可能作为“假递质”在视网膜中替代γ-氨基丁酸的观点。
