L-茶氨酸对断乳大鼠血清及肝脏氨基酸谱的影响

Effect of L-Theanine on Serum and Liver Amino Acid Compositions in Weaning Rats

以断乳大鼠为实验对象,通过灌胃L-茶氨酸溶液,分析大鼠血清及肝脏中氨基酸谱变化,探究L-茶氨酸对大鼠氨基酸吸收与代谢及生长发育的影响。实验使用64只断乳大鼠(雌雄各半),随机分为对照组、低剂量组、中剂量组和高剂量组,分别灌胃L-茶氨酸0、50、200、400 mg/(kg·d)(以体质量计,下同)。连续灌胃14 d后采集肝脏和血液,利用氨基酸分析仪检测样品中氨基酸和氨的含量。结果表明:L-茶氨酸显著增加了断乳大鼠的日增体质量、末体质量以及肝脏中生糖氨基酸(Gly、Ser、Ala、Met、His、Val、Pro、Asp、Asn、Glu、Gln)或兼性生糖氨基酸(Thr、Ile、Phe、Tyr)的含量。与对照组相比,肝脏中所有必需氨基酸及多数非必需氨基酸含量在200 mg/(kg·d)L-茶氨酸处理组显著提高(P<0.05)。血清中大多数氨基酸含量在400 mg/(kg·d)L-茶氨酸剂量处理组显著降低(P<0.05)。L-茶氨酸显著增加(P<0.05)血液及肝脏中Gln的含量,血氨含量随L-茶氨酸剂量增加呈线性降低(P<0.001)。由此说明,L-茶氨酸能够促进大鼠对日粮氨基酸的吸收,影响血清及肝脏中氨基酸含量,进而调节大鼠的生长发育。此外,L-茶氨酸通过增加Gln和Glu含量从而促进血氨的排出,减少氨对大鼠机体的毒害。

In order to investigate the effect of L-theanine on amino acid （AA） metabolism, growth and development of rats,weaning rats were administered with L-theanine solution to determine changes in AA compositions in serum and liver.Sixty-four healthy SD rats with half males and females were randomly divided into 4 groups, which were administered withL-theanine at the dosages of 0, 50, 200 and 400 mg/（kg·d）, respectively. On the 15th day of the experiment, all rats weresacrificed after 24 h fasting to collect serum and liver for measurement of free AA and ammonia by an AA analyzer. Theresults showed that L-theanine increased the daily weight gain, final body weight and glucogenic AAs （Gly, Ser, Ala, Met,His, Val, Pro, Asp, Asn, Glu and Gln） or facultative glucogenic AAs （Thr, Ile, Phe and Tyr） in the liver of rats. Comparedwith the control group, the contents of total essential AAs and some nonessential AAs in the liver of rats administered with200 mg/（kg·d） L-theanine were increased significantly, and the contents of most AAs in serum were decreased significantly.L-theanine significantly elevated the concentration of Glu in serum and liver, and the content of ammonia decreasedlinearly with L-theanine dose. All results indicated that L-theanine could promote the absorption of dietary AAs, affect AAconcentrations in serum and liver and regulate the growth and development of rats. Meanwhile, L-theanine could increaseGlu concentration and subsequently promote the emission of ammonia to alleviate its harm to the organism.