Ornithine metabolism in normal subjects and patients with cancer.
The metabolism of L-(1-14C)ornithine monohydrochloride was monitored in patients with histologically proven cancer and in normal volunteers. Following i.v. injection of 8 microCi C-14 ornithine (160 nmoles), the decarboxylation of ornithine--yielding 14CO2--was monitored for a 2.5-hr period using the ionization chamber and vibrating-reed electrometer of Tolbert, as modified by Davidson and Schwabe. Twelve normal subjects exhaled 7.3-15.7% of the administered C-14 (mean 12.6% s.d. 3.11%). In ten patients tested before initiation of therapy, recovery ranged from 18.2-32.1% (mean 23.02%, s.d. 4.52%). A t-test indicates a confidence level of > 99.5% that a significant difference exists between the two means. Re-testing of two normal volunteers showed little or no change in ornithine metabolism over a 2-5-mo period. Results from testing three cancer patients before and after therapy correlate well with clinical evidence of the presence of tumor burden.
D000328:Adult; D002245:Carbon Dioxide / Q000378:metabolism*; D003653:Decarboxylation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000532:radiotherapy; D009952:Ornithine / Q000378:metabolism / Q000494:pharmacology*; D009955:Ornithine Decarboxylase / Q000378:metabolism; D011247:Pregnancy; D012119:Respiration
D002245:Carbon Dioxide; D009952:Ornithine; D009955:Ornithine Decarboxylase