Regulation on new regulation in photoreceptor signal transduction

(1)S-（1，2-二羧乙基）谷胱甘肽（DCE-GS）及其酯类对乙酰氨基酚所致大鼠肝毒性的保护作用DCE-GS三酯预处理可预防乙酰氨基酚所致的肝毒性。结果发现，DCE-GS三酯给药可抑制乙酰氨基酚引起的GSH耗竭，表明DCE-GS三酯对乙酰氨基酚诱导的肝毒性的保护作用是由于肝脏GSH水平的保留。(2)DCE-GS三酯对谷胱甘肽水平的升高作用研究了DCE-GS对大鼠肝匀浆GSH合成，特别是对G-谷氨酰半胱氨酸合成的影响。结论：DCE-GS通过激活谷氨酰半胱氨酸合成酶促进肝脏GSH合成。(3)酵母中的DCE-GS DCE-GS存在于酿酒酵母中。DCE-GS合成酶是从酵母中纯化得到的。该酶的分子量为49 kDa。(4)啤酒酵母在有氧和厌氧条件下培养时，半胱氨酸、谷胱甘肽及其相关化合物的含量和相关酶活性的变化。有氧培养的啤酒酵母提高了过氧化氢酶和超氧化物歧化酶等抗氧胁迫的防御酶的活性和保护性化合物半胱氨酸和谷胱甘肽的水平。谷胱甘肽合成的增加可能与半胱氨酸水平的增加有关，而半胱氨酸水平的增加又被发现是由胱硫醚b合成酶的氧依赖性激活控制的。

(1) Protective effect of S- (1,2-dicarboxyethyl) glutathione (DCE-GS) and its esters on acetoaminophen-induced hepatotoxicity in ratsThe pretreatment of DCE-GS triester prevented acetoaminophen-induced hepatotoxicity. It was found that the DCE-GS triester administration inhibited the GSH depletion caused by acetoaminophen, suggesting that the protective effect of DCE-GS triester on acetoaminophen-induced hepatotoxicity was due to the retention of hepatic GSH level.(2) Elevation effect of DCE-GS triester on glutathione levelThe effect of DCE-GS on GSH synthesis, especially g-glutamylcysteine synthetase, was studied in rat liver homogenate. In conclusion, DCE-GS promoted the hepatic GSH synthesis due to activation g-glutamylcysteine synthetase.(3) DCE-GS in YeastDCE-GS was found in Saccharomyces cerevisiae. The DCE-GS synthesizing enzyme was purified from yeast. The molecular mass of the enzyme was 49 kDa.(4) Contents of cysteine, glutathione and their related comounds as well as related enzyme activities in Saccharomyces serevisiae cultured under aerobic and anaerobic ocnditionsYeast grown aerobically increased activities of defensive enzymes against an oxygen stress like catalase and superoxide dismutase, and levels of the protective comounds cysteine and glutathione. The elevated synthesis of glutathione could be associated to the increased levels of cysteine which in its turn was found to be controlled by the oxygen dependent activation o cystathionie b-synthetase