Objective   To investigate the effects of taurine on the contents of amino acid neurotransmitter: glutamate Glu, γ-aminobutyric acidGABA, and taurine in rat blood or retina in light and dark adaptation.

  Methods   Weanling rats were allocated randomly to three experimental groups: control group, lower dosage taurine-treated group, higher dosage taurine-treated group.After supplementation of taurine in rat diet for four weeks, the contents of Glu, GABA, taurine in blood or retina under the conditions of light and dark adaptation were measured with Amion Acid Analyzer.

  Results   After long time dark adaptation, the contents of retinal taurine decreased significantly, the contents of retinal Glu increased, but the contents of retinal GABA didn't change.When taurine was supplemented in rat diet, the levels of taurine in blood and retina increased significantly, but the levels of retinal Gluincreased in light adaptation and reduced in dark adaptation.The levels of retinal GABA increased in both conditions of light and dark adaptation.

  Conclusion   Taurine and Glu are involved in dark adaptation.Taurine probably modulated signal transmission in rat retina through regulating the contents of Glu and GABA in retina.