Arutiunian Zh E, Gevorgian G A, Petrosian A M
Zh Evol Biokhim Fiziol. 1981 Nov-Dec;17(6):542-6.
Studies have been made of the effect of changes in illumination levels on 14C + GABA efflux in the isolated retina of the frog R. ridibunda. When the retina loaded with 14C-GABA is stimulated by darkness, the efflux of radioactivity immediately increases. After reaching a peak, the efflux of 14C-GABA slightly decreases attaining steady level which is higher than the level of spontaneous efflux observed during weak (approximately 0.05 lux) illumination. This high level is preserved as long as the retina remains in darkness. During illumination of the retina (transition from darkness to 60 lux), two types of response are observed. In some cases, insignificant increase of GABA efflux from the retina is followed by its rapid decrease up to the level which is observed during weak illumination. In other cases, immediately after illumination the decrease in GABA efflux takes place (in 6 experiments out of 10). In accordance with the data of Voaden [6], it is suggested that 14C + GABA is liberated from horizontal and amacrine cells. The data obtained in the present investigation are discussed in terms of Trifonov [14] and Byzov [15] hypothesis. These data confirm the idea that GABA acts as a retinal neurotransmitter in the frog.
已经对光照水平变化对泽蛙离体视网膜中14C + GABA流出的影响进行了研究。当用14C - GABA加载的视网膜受到黑暗刺激时，放射性流出立即增加。达到峰值后，14C - GABA的流出略有下降，达到稳定水平，该水平高于在弱光（约0.05勒克斯）照射期间观察到的自发流出水平。只要视网膜保持在黑暗中，这个高水平就会保持。在视网膜光照期间（从黑暗过渡到60勒克斯），观察到两种类型的反应。在某些情况下，视网膜中GABA流出量略有增加，随后迅速下降至弱光照射期间观察到的水平。在其他情况下，光照后立即发生GABA流出量的减少（10次实验中有6次）。根据沃登[6]的数据，有人提出14C + GABA是从水平细胞和无长突细胞中释放出来的。本研究中获得的数据根据特里福诺夫[14]和别佐夫[15]的假说进行了讨论。这些数据证实了GABA在青蛙中作为视网膜神经递质起作用的观点。
