title: Ornithine decarboxylase in resting human mononuclear leucocytes: evidence for an endogenous inhibitor.
abstract: 1. Ornithine decarboxylase (ODC) was measured in human mononuclear leucocytes (HML) by retention of putrescine on cation exchange paper. 2. The method was validated with unstimulated HML, phytohemagglutinin-stimulated HML, and a commercial preparation of ODC. The average enzyme activity of unstimulated HML (50 samples) was 22.6 +/- 7.3 pmol/hr 10(7) cells, with 29 values less than 5 pmol/hr 107 cells. 3. The results show that an endogenous inhibitor or inactivator of ODC exists in unstimulated HML: enzyme activity in extracts of mitogen-stimulated cells were inhibited by extracts of unstimulated cells (37-55%) inhibition under the conditions used.
authors.affiliation: Preventive Medicine Institute Strang Clinic, New York, NY 10016.
authors.forename: D B
authors.initials: DB
authors.lastname: Johnson
authors.forename: R W
authors.initials: RW
authors.lastname: Pero
authors.forename: R
authors.initials: R
authors.lastname: Morgenstern
authors.forename: P E
authors.initials: PE
authors.lastname: Joseph
authors.forename: D G
authors.initials: DG
authors.lastname: Miller
mesh_terms: D002411:Cation Exchange Resins; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000201:enzymology*; D009955:Ornithine Decarboxylase / Q000097:blood*; D065108:Ornithine Decarboxylase Inhibitors; D011700:Putrescine / Q000096:biosynthesis; D013936:Thymidine
chemical_list: D002411:Cation Exchange Resins; D065108:Ornithine Decarboxylase Inhibitors; D009955:Ornithine Decarboxylase; D011700:Putrescine; D013936:Thymidine