Wakabayashi Y, Yamada E, Yoshida T, Takahashi N
Department of Biochemistry, Kyoto Prefectural University of Medicine, Japan.
Am J Physiol. 1995 Aug;269(2 Pt 1):G313-8. doi: 10.1152/ajpgi.1995.269.2.G313.
The small intestine has been presumed to release citrulline as a precursor for the endogenous arginine synthesis. We studied the effect of intestinal resection and arginine-free diet on rat physiology. We maintained rats with massively resected small intestine (R rats) and those with transected intestines (T rats) on either control or an arginine-free diet. After 4 wk, R rats fed deficient diet [R(-)] lost weight by a mean of 46 g, whereas R rats fed control diet [R(+)] and T rats fed control [T(+)] and deficient diet [T(-)] gained 30-96 g. Average nitrogen balance was 150, 60, 110, and -33 mg/day for T(+), T(-), R(+), and R(-), respectively. The concentrations of arginine in skeletal muscle were 654, 163, 230, and 84 nmol/g, respectively, and those in plasma were 133, 50, 103, and 54 microM, respectively. The concentrations of citrulline in R rats were halved compared with T rats irrespective of diet. We conclude that arginine is synthesized in a small intestine-dependent manner in the rat.
小肠被认为可释放瓜氨酸作为内源性精氨酸合成的前体。我们研究了肠切除和无精氨酸饮食对大鼠生理的影响。我们将小肠大量切除的大鼠（R大鼠）和肠横断的大鼠（T大鼠）分别维持在对照饮食或无精氨酸饮食状态。4周后，喂食缺乏饮食的R大鼠[R(-)]平均体重减轻46克，而喂食对照饮食的R大鼠[R(+)]以及喂食对照饮食[T(+)]和缺乏饮食[T(-)]的T大鼠体重增加了30 - 96克。T(+)、T(-)、R(+)和R(-)的平均氮平衡分别为150、60、110和 -33毫克/天。骨骼肌中精氨酸的浓度分别为654、163、230和84纳摩尔/克，血浆中精氨酸的浓度分别为133、50、103和54微摩尔/升。无论饮食如何，R大鼠中瓜氨酸的浓度与T大鼠相比减半。我们得出结论，大鼠体内精氨酸是以小肠依赖的方式合成的。
