Tews J K, Colosi N W, Harper A E
Am J Physiol. 1975 May;228(5):1606-14. doi: 10.1152/ajplegacy.1975.228.5.1606.
Within 1.5 h after force-feeding rats one meal of enzymatic hydrolysates of casein, gelatin, lactalbumin, or yeast, alpha-aminoisobutyric acid (AIB) transport in liver slices was stimulated two- to threefold. A complete amino acid mixture also increased AIB transport. Of the 15 amino acids or derivatives tested individually, the dispensable amino acids, especially glycine and alanine, were more stimulatory than the essential amino acids; feeding a mixture of amino acids lacking glycine and alanine increased AIB uptake only slightly. The effects were significantly greater in meal-fed than in ad libitum-fed rats. Increased hepatic concentrations of cyclic AM were usually associated with the increase in AIB transport. Feeding glucose inhibited the increases in transport and cyclic AMP concentration induced by casein hydrolysate or in the stimulation of AIB transport by dietary amino acids. The increases in AIB uptake appeared unrelated to the exchange of endogenous amino acids with medium AIB.
给大鼠强制喂食一顿酪蛋白、明胶、乳白蛋白或酵母的酶水解产物后1.5小时内，肝切片中α-氨基异丁酸（AIB）的转运被刺激了两到三倍。完整的氨基酸混合物也增加了AIB的转运。在单独测试的15种氨基酸或衍生物中，非必需氨基酸，尤其是甘氨酸和丙氨酸，比必需氨基酸的刺激作用更强；喂食缺乏甘氨酸和丙氨酸的氨基酸混合物只会略微增加AIB的摄取。与自由采食的大鼠相比，在强制喂食的大鼠中这些作用明显更强。肝中环磷酸腺苷（cAMP）浓度的升高通常与AIB转运的增加相关。喂食葡萄糖可抑制酪蛋白水解产物诱导的转运增加和环磷酸腺苷浓度升高，或抑制膳食氨基酸对AIB转运的刺激作用。AIB摄取的增加似乎与内源性氨基酸与培养基中AIB的交换无关。
