ABNORMALITIES IN N15 EXCRETION RATES AFTER INGESTION OF TAGGED GLYCINE IN CUSHING'S SYNDROME AND FOLLOWING ACTH ADMINISTRATION 1

Abstract

The rate of N15 ex-cretion in the urine following ingestion of tagged glycine has been detd. on 7 healthy subjects in N equilibrium on a standard diet. In 4 patients with Cushing''s syndrome, the subject was in N equilibrium but the rate of excretion was increased; in 1 negative N balance, the degree of alteration was similar. In 1 case of Cushing''s syndrome an X-ray-induced partial remission and in another testosterone propionate produced a positive N balance and a fall in the rate of N15 excretion toward normal. Admn. of ACTH on 3 occasions to 2 healthy subjects increased the Nl5 excretion rate, but promoted negative N balance on 2 occasions only. These data support the concept that hyper-adrenocorticism may be characterized by an increased rate of degradation of ingested amino acid and decreased protein synthesis.