Abstract
Rats were paired fed the diet containing 10% complete amino acid mixture and each essential amino acid devoid diets for 8 days. Enough amounts of thiamine, riboflavin, vitamin B_6,and niacin were intraperitoneally injected. Excretion of thiamine and vitamin B_6 from urine of the control and test diets groups was not much different, but those of riboflavin and N'-methylnicotinamide (MNA) in urine of the amino acid devoid group were fairly higher than those of the control group. It was presumed from the result that tryptophan normally used for protein synthesis was limited by the omission of one essential amino acid, then took a passway to NAD and excreted in urine as MNA more than that of the control group. Liver riboflavin content of rats fed the essential amino acid-devoid diet was generally lower than that of the control group. The tendency was greater in rats fed threonine or methionine devoid diet.
