Influence of diet on cystathionine ketimine and lanthionine ketimine content in human urine.

A simple HPLC procedure for the routine analyses of Cystathionine ketimine (CK) and Lanthionine ketimine (LK) content in human urine has been developed. The values obtained in morning urine of fifteen healthy subjects (both sexes, 25-45 years old) on a common mixed diet are 330-2480 micrograms/g creatinine (mean 1110) of CK and 100-420 micrograms/g creatinine (mean 200) of LK. Quantitation of the two ketimines in urine of subjects on strictly vegetarian diet indicate that while the excretion of LK is independent of the diet, the excretion of CK is significantly decreased in conditions of vegetarian diet.