The relation of dietary protein consumption to N-15 excretion in normal subjects and in Cushing's syndrome utilizing N-15 glycine orally and intravenously.

In a previous paper (1) we have reported studies on the percentage of N-15 excreted over a twenty-four hour period following the oral administration of N-15 glycine to normal subjects and to patients with Cushing's syndrome in nitrogen equilibrium on diets containing approximately one gram of protein per kilogram of body weight. During this study it was noted that the level of protein intake influenced the percentage of N-15 excreted in the urine, an observation first reported by Sprinson (2) in animals and in a healthy volunteer. The present paper presents data on the influence of various levels of protein intake on the percentage of N-15 excreted in the urine over a twenty-four hour period following either oral or intravenous administration of N-15 glycine to healthy volunteers. Similar data from a patient with Cushing's syndrome given N-15 glycine orally are also presented.