The Effect Of Different Doses Of Branched-chain Amino Acids Supplemented On Serotonin And Its Precursors In Hypothalamic Of Exercise Rat

Objective: To observe the effects of BCAASupplementation on BCAA,f-Trp and5-HT in hypothalamic extracellular fluid in rats recoveringfrom, exhaustive swimming, to analyze whether BCAA Supplementationcan improve the exercise capacity of rats and compare the effect ofdifferent doses of BCAA supplement, explore the optimal dose ofsupplement BCAA.Methods:32rats were randomly divided into control group, small-dosesupplement group (1.25g/kg body weight), middle supplementary dosegroup (2.5g/kg body weight) and high-dose supplement group (5g/kgbody weight), each group including8rats. One rat was randomlyselected from each group to determine the exhaustive exerciseload. BCAA supplementation group was once a day in the morning andBCAA supplement six times a week expected Sunday, lasting supplementfor six weeks. After six weeks, the blood was collected from tail vein ofrats to test ammonia in the afternoon the day before exhaustedswimming. Rats were anesthesia with20%urethane1mL/200g weightsubcutaneous injection after exhaustive swimming positioning withstereotaxic instrument, the guide tube implanted the right side of thehypothalamus (AP:+0.03mm, ML:+0.08mm, DV:-0.67mm) and fixedmicrodialysis probes along the guide tube is inserted into the right side ofhypothalamus, infusion of artificial cerebrospinal fluid with the speed of 2μl/min to balance2h; and collecting microdialysis samples4h,5h,6h,8h and24h after exercise respectively. By capillary electrophoresis-laser induced to assay the concentration of BCAA f-Trp and5-HT inhypothalamic extracellular fluid。Results:1, BCAA supplementation for six weeks did not significantlyaffect the body weight growth of rats.2, BCAA supplementation for sixweeks, compared with the the blood ammonia of control group, thelow-dose group did not significantly changed, medium dose groupsignificantly increased（P <0.05）, high-dose group was significantlyhighe（rP <0.01）.3, The four groups of rats were exhausted swamming,the time of medium dose group was longest and high-dose group wasshortest.4, During the exhaustive swimming convalescence, theextracellular fluid f-Trp of hypothalamic significantly decreased withtime prolonged, and f-Trp was no significant difference at the same time.The ratio of plasma f-Trp/BCAA decreased with time prolonged.5,Compared with the control group, the extracellular fluid5-HT oflow-dose group and medium dose group peaked delay, and theconcentration of low-dose group down overall, and medium dose grouprise overall.Conclusion:1, The effect of BCAA supplementation onrotein synthesis and fat reduction are dynamic equilibrium.2, With the doses of BCAA supplementation increasing, the blood ammoniaincreased. Low-doses of BCAA supplementation had no effect on bloodammonia generation.3, BCAA supplementation can improve theexhaustive swimming ability of rats, however, the exercise ability wasnot increased accompanied with the doses of BCAA supplementedimproved.4, BCAA supplementation maybe improved theability of plasma BCAA and f-Trp competition through thethe blood-brain barrier, and BCAA supplementation maybe delay andreduce the production of5-HT in brain.5,Small dose (1.25g/kg· BW) of BCAA supplementation isthe best to improve the exercise capacity of rats.