Open AccessInduction of Ornithine Decarboxylase in Guinea Pig Lymphocytes by the Divalent Cation Ionophore A23187
Author(s) -
OTANI Shuzo,
KURAMOTO Ayako,
MATSUI Isao,
MORISAWA Seiji
Publication year - 1982
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1982.tb06647.x
Subject(s) - ornithine decarboxylase , dna synthesis , divalent , stimulation , thymidine , ionophore , ornithine , medicine , endocrinology , biology , biochemistry , chemistry , microbiology and biotechnology , in vitro , enzyme , arginine , amino acid , organic chemistry , membrane
The divalent cation ionophore, A23187, at a concentration of 0.25 μg/ml, enhanced influx of Ca 2+ . activity of ornithine decarboxylase and incorporation of [ 3 H]thymidine into DNA of guinea pig lymphocytes. Combined treatment of cells with A23187 and dibutyryladenosine 3′. 5′‐monophosphate (Bt 2 cAMP) augmented these three events. A23187 at a concentration of 0.06 μg/ml which was insufficient for induction of ornithine decarboxylase stimulated neither Ca 2+ influx nor [ 3 H]thymidine incorporation, but stimulated Ca 2+ efflux. A23 187 (0.06 μg/ml) in combination with Bt 2 cAMP caused a marked induction of ornithine decarboxylase and stimulation of [ 3 H]thymidine incorporation into DNA. When the time of Bt 2 cAMP addition was delayed after A23187, the stimulation of ornithine decarboxylase activity decreased. Washout of Bt 2 cAMP from cell culture earlier than 4 h of incubation caused a reduction in the stimulatory effect of Bt 2 cAMP. These results suggest that raising concentrations of cytoplasmic Ca 2+ and cellular cAMP are important to some initial events leading to induction of ornithine decarboxylase and these biochemical changes are obligatory sequential steps for stimulation of DNA synthesis.