Intermediary Metabolism of Histidine

The two optical isomers of β-4-imidazolelactic acid were prepared from the d-and l- histidine monohydrochlorides by means of silver nitrite. These were fed in diets containing casein hydrolysates from which the histidine had been removed by precipitation as the silver salt (Hydrolysate A) or as the mercuric sulfate complex (Hydrolysate B)