Tamaki N, Funatsuka A, Fujimoto S, Hama T
J Nutr Sci Vitaminol (Tokyo). 1984 Dec;30(6):541-51. doi: 10.3177/jnsv.30.541.
Carnosine can support the growth of rats fed on a histidine-free diet. Rats fed on the histidine-free diet lost weight rapidly for a few days, then remained at a relatively constant weight for 2 weeks at least. However, rats fed on a 0.90% carnosine diet, which contains histidine equimolar to that in a 20% casein diet, increased their weight at the same rate as rats fed on a 20% amino acid diet simulated with casein. On the other hand, the growth of rats fed on a 5% carnosine diet was about 70% compared with that of control rats fed on the 20% amino acid diet for a 2-week experimental period. Carnosinase activity was not significantly affected in the kidney of rats fed on the histidine-free or the 5% carnosine diet. On the other hand, carnosinase activity in the small intestine of rats fed on the histidine-free diet was significantly increased. Histidine content of serum of rats fed on the histidine-free diet decreased to 1/3 of that of control rats, while that of rats fed on the 5% carnosine diet increased to about 14 times. Carnosine content of rat gastrocnemius muscle increased with carnosine content of diets, followed by an increase of histidine in the muscle. However, carnosinase activity of gastrocnemius muscle was not affected by carnosine in diets.
肌肽能够支持以无组氨酸饮食喂养的大鼠的生长。以无组氨酸饮食喂养的大鼠在最初几天体重迅速下降，随后至少两周体重维持相对稳定。然而，食用含0.90%肌肽饮食（其组氨酸含量与20%酪蛋白饮食中的组氨酸含量等摩尔）的大鼠，体重增加速度与食用经酪蛋白模拟的20%氨基酸饮食的大鼠相同。另一方面，在为期2周的实验期内，食用5%肌肽饮食的大鼠的生长量约为食用20%氨基酸饮食的对照大鼠的70%。食用无组氨酸或5%肌肽饮食的大鼠肾脏中的肌肽酶活性未受到显著影响。另一方面，食用无组氨酸饮食的大鼠小肠中的肌肽酶活性显著增加。食用无组氨酸饮食的大鼠血清中的组氨酸含量降至对照大鼠的1/3，而食用5%肌肽饮食的大鼠血清中的组氨酸含量增加至约14倍。大鼠腓肠肌中的肌肽含量随饮食中肌肽含量的增加而增加，随后肌肉中的组氨酸含量也增加。然而，腓肠肌中的肌肽酶活性不受饮食中肌肽的影响。
