nonspecific nitrogen was either a ) a mixture of six dispensable amino acids and arginine ( diet 1 ) or arginine and histidine ( diet 2 ) in casein proportions , or b ) an isonitrogenous mixture of glycine and diammonium citrate alone ( diet 3 ) , with histidine ( diet 4 ) , arginine ( diet 5 ) , or histidine and arginine ( diet 6 ) .
C0002520
amino
C0017890
glycine