【摘要】 以淡水白鲳(Colossoma brachypomum)鱼种为试验对象,养殖试验周期为60 d。平均试验水温(26.5±0.5)℃。基础饲料粗蛋白水平(质量分数)为41.03％,添加盐酸甜菜碱水平(质量分数)分别为0、0.1％、0.2％、0.4％、O.6％和0.8％。试验结束后,停饲24h取样测定。结果表明,盐酸甜菜碱使整鱼水分含量呈下降趋势(P>0.05),粗蛋白含量呈上升趋势,其中,0.6％甜菜碱组整鱼粗蛋白提高11.89％(P<0.05);鱼肌肉含水量下降,0.1％、O.6％和O.8％甜菜碱组分别降低1.29％(P<0.05)、1.42％(P<0.05)和2.45％(P<0.01),肌肉粗蛋白含量提高,0.4％甜菜碱组提高3.19％(P<0.05);肝脏粗蛋白含量提高,0.2％、0.4％、0.6％和0.8％组分别提高1.04％、O.74％、0.75％和0.87％(4组P<0.01);盐酸甜菜碱显著提高肌肉和肝脏中RNA和TNA含量及RNA与DNA比率;盐酸甜菜碱显著提高肝脏中甜菜碱-高半胱氨酸甲基转移酶和胱硫醚β-合成酶总活力和比活力。本试验结果提示,甜菜碱在肝脏BHMT和β-CYST的双重调控下作为甲基供体参与机体代谢活动,使肝脏和肌肉中甲基化产物(如:核酸)含量增加,从而实现其促进蛋白质合成的功能。更多还原

【Abstract】 This research was conducted to investigate methyl transfer function and protein synthesis mechanism of betaine hydrochloride in Colossoma brachypomum fingerlings (initial body weight 83.14-15. 36 g) from October to December 1997. One hundred and ninety eight individuals were divided into six groups, each of which included three replicates. The fish were fed with the same basal diet (crude protein content 41.03% ) supplemented with 0 ( control group) , 0.2% , 0.4% , 0.6% and 0. 8% betaine hydrochloride, respectively (test groups). The test period was 60 days under the conditions of circulation, filtration and controlled temperature. The results show that additive betaine hydrochloride can decrease the moisture and increase the content of crude protein in whole fish. In the 0.6% betaine hydrochloride group the crude protein content of whole fish increased by 11. 89% compared with the control (P<0.05) , and in the groups of 0. 1% , 0.6% and 0.8% betaine hydrochloride, the moisture in fish muscle decreased by 1.29% (P <0.05), 1.42% (P <0.05), and 2.45% (P < 0.01), respectively. In 0.4% betaine hydrochloride group the crude protein content in fish muscle increased by 3. 19% (P <0. 05). In the groups of 0. 2% , 0.4% , 0.6 and 0. 8% betaine hydrochloride, the content of crude protein in fish live increased by 1.04%(P<0.01), 0.74%(P<0.01), 0. 75% (P <0.01) and 0.87% (P<0.01). Also, betaine hydro-chloride can increase the contents of RNA, TNA and ratio of RNA content to DNA content in fish muscle and liver significantly, and can increase the total and specific activities of betaine-homocystein S-methyltransferase and cysta-thionine β-synthase, respectively. All these imply that betaine hydrochloride can act as the methyl group donator to participate the metabolism of organism under the double regulation of BHMT and β-CYST so that it can increase methylic products in fish liver and muscle (e. g. nucleic acids) and the protein synthesis is prompted.更多还原