scholarly journals Ornithine decarboxylase activity in chick duodenum induced by 1 α, 25-dihydroxycholecalciferol

1981 ◽  
Vol 195 (3) ◽  
pp. 685-690 ◽  
Author(s):  
T Shinki ◽  
N Takahashi ◽  
C Miyaura ◽  
K Samejima ◽  
Y Nishii ◽  
...  
Keyword(s):  
Vitamin D ◽  
Enzyme Activity ◽  
Ornithine Decarboxylase ◽  
Calcium Absorption ◽  
Duodenal Mucosa ◽  
Decarboxylase Activity ◽  
Absorption Mechanism ◽  
Deficient Diet ◽  
Ornithine Decarboxylase Activity ◽  
Hormone Administration

The effect of cholecalciferol and its metabolites on ornithine decarboxylase activity was investigated in the duodenal mucosa of vitamin D-deficient chicks. The duodenal ornithine decarboxylase activity decreased in animals fed a vitamin D-deficient diet and its retarded activity was increased dose-dependently by a single injection of cholecalciferol. Among various metabolites of cholecalciferol tested, 1 alpha, 25-dihydroxycholecalciferol [ 1 alpha, 25 (OH)2D3] was the most potent stimulator. Stimulation of the enzyme activity was detected as early as 2h after intravenous administration of 1 alpha, 25 (OH)2D3 and a maximal value was attained at 6 h. The maximal value was 27 times higher than the control. In addition, treatment with 1 alpha 25 (OH)2D3 affected the duodenal content of polyamines. The content of putrescine increased to a value of three times that of the control 6 h after the hormone administration. The spermidine content did not change appreciably. The enhancement of duodenal ornithine decarboxylase activity by 1 alpha, 25 (OH)2D3 occurred in parallel with the enhancement of calcium absorption, which was first detected 3 h after the hormone administration. The enhancement appeared to be tissue-specific. It was observed in every intestinal segment, but was highest in the duodenum. Enzyme activity in other tissues was not influenced appreciably by 1 alpha, 25 (OH)2D3. These results clearly indicate that the duodenal biosynthesis of polyamines is regulated by 1 alpha, 25 (OH)2D3, suggesting the possibility that duodenal ornithine decarboxylase may be involved in the calcium absorption mechanism.

scholarly journals The effects of 24R,25-dihydroxycholecalciferol and of 1 α,25-dihydroxycholecalciferol on ornithine decarboxylase activity and on DNA synthesis in the epiphysis and diaphysis of rat bone and in the duodenum

1983 ◽  
Vol 214 (2) ◽  
pp. 293-298 ◽  
Author(s):  
D Sömjen ◽  
I Binderman ◽  
Y Weisman
Keyword(s):  
Vitamin D ◽  
Enzyme Activity ◽  
Ornithine Decarboxylase ◽  
Thymidine Incorporation ◽  
Single Injection ◽  
Fold Increase ◽  
Decarboxylase Activity ◽  
Long Bones ◽  
Vitamin D Metabolites ◽  
Ornithine Decarboxylase Activity

The effect of cholecalciferol metabolites on ornithine decarboxylase activity and on DNA synthesis in developing long bones was investigated in vitamin D-depleted rats. In the epiphysis there was a 6.4-fold increase in ornithine decarboxylase activity 5 h after a single injection of 24R,25-dihydroxycholecalciferol but not of 24S,25-dihydroxycholecalciferol or other vitamin D metabolites. In comparison, in the diaphysis and duodenum, 1 alpha,25-dihydroxycholecalciferol, but not other vitamin D metabolites, caused a 3-3.5-fold increase in the enzyme activity. The enzyme activity in the tissues examined attained a maximal value at 5 h after the injection of the metabolites. The activity of ornithine decarboxylase in the epiphysial region increased dose-dependently as the result of a single injection of 24R,25-dihydroxycholecalciferol and attained a maximal value at a dose between 30 and 3000 ng. In addition, administration of 24R,25-dihydroxycholecalciferol, but not 24S,25-dihydroxycholecalciferol or other metabolites, caused within 24 h a 1.7-2.0-fold increase in [3H]thymidine incorporation into DNA of the epiphyses of tibial bones. In comparison, 1 alpha,25-dihydroxycholecalciferol caused a 1.5-fold increase in [3H]thymidine incorporation into DNA of the diaphyses and of the duodenum. The present data indicate that 24R,25-dihydroxycholecalciferol is involved in the regulation of epiphyseal growth, whereas 1 alpha,25,dihydroxycholecalciferol stimulates the proliferation of cells in the diaphysis of long bones and in the intestinal mucosa.

scholarly journals Role of pyridoxal phosphate in mammalian polyamine biosynthesis. Lack of requirement for mammalian S-adenosylmethionine decarboxylase activity

1977 ◽  
Vol 166 (1) ◽  
pp. 81-88 ◽  
Author(s):  
A E Pegg
Keyword(s):  
Ornithine Decarboxylase ◽  
Pyridoxal Phosphate ◽  
Vitamin B ◽  
Decarboxylase Activity ◽  
Deficient Diet ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Ornithine Decarboxylase Activity

1. Polyamine concentrations were decreased in rats fed on a diet deficient in vitamin B-6. 2. Ornithine decarboxylase activity was decreased by vitamin B-6 deficiency when assayed in tissue extracts without addition of pyridoxal phosphate, but was greater than in control extracts when pyridoxal phosphate was present in saturating amounts. 3. In contrast, the activity of S-adenosylmethionine decarboxylase was not enhanced by pyridoxal phosphate addition even when dialysed extracts were prepared from tissues of young rats suckled by mothers fed on the vitamin B-6-deficient diet. 4. S-Adenosylmethionine decarboxylase activities were increased by administration of methylglyoxal bis(guanylhydrazone) (1,1′-[(methylethanediylidine)dinitrilo]diguanidine) to similar extents in both control and vitamin B-6-deficient animals. 5. The spectrum of highly purified liver S-adenosylmethionine decarboxylase did not indicate the presence of pyridoxal phosphate. After inactivation of the enzyme by reaction with NaB3H4, radioactivity was incorporated into the enzyme, but was not present as a reduced derivative of pyridoxal phosphate. 6. It is concluded that the decreased concentrations of polyamines in rats fed on a diet containing vitamin B-6 may be due to decreased activity or ornithine decarboxylase or may be caused by an unknown mechanism responding to growth retardation produced by the vitamin deficiency. In either case, measurements of S-adenosylmethionine decarboxylase and ornithine decarboxylase activity under optimum conditions in vitro do not correlate with the polyamine concentrations in vivo.

scholarly journals Diamine-induced inhibition of liver ornithine decarboxylase

1979 ◽  
Vol 177 (1) ◽  
pp. 63-69 ◽  
Author(s):  
Arja Kallio ◽  
Monica Löfman ◽  
Hannu Pösö ◽  
Juhani Jänne
Keyword(s):  
Enzyme Activity ◽  
Ornithine Decarboxylase ◽  
Enzyme Inhibitor ◽  
Decarboxylase Activity ◽  
Enzyme Protein ◽  
Intracellular Degradation ◽  
Ornithine Decarboxylase Activity ◽  
Normal Rat

Re!peated injections of 1,3-diaminopropane, a potent inhibitor of mammalian ornithine decarboxylase, induced protein-synthesis-dependent formation of macromolecular inhibitors or ‘antienzymes’ [Heller, Fong & Canellakis (1976) Proc. Natl. Acad. Sci. U.S.A.73, 1858–1862] to ornithine decarboxylase in normal rat liver. Addition of the macromolecular inhibitors, produced in response to repeated injections of diaminopropane, to active ornithine decarboxylase in vitro resulted in a profound loss of the enzyme activity, which, however, could be partly recovered after passage of the enzyme–inhibitor mixture through a Sephadex G-75 columin in the presence of 0.4m-NaCl. This treatment also resulted in the appearance of free inhibitor. In contrast with the separation of the enzyme and inhibitory activity after combination in vitro, it was not possible to re-activate, by using identical conditions of molecular sieving, any inhibited ornithine decarboxylase from cytosol fractions obtained from animals injected with diaminopropane. However, the idea that injection of various diamines, also in vivo, induces acute formation of macromolecular inhibitors, which reversibly combine with the enzyme, was supported by the finding that the ornithine decarboxylase activity remaining after diaminopropane injection appeared to be more stable to increased ionic strength than the enzyme activity obtained from somatotropin-treated rats. Incubation of the inhibitory cytosol fractions with antiserum to ornithine decarboxylase did not completely abolish the inhibitory action of either the cytosolic inhibitor or the antibody. A single injection of diaminopropane produced an extremely rapid decay of liver ornithine decarboxylase activity (half-life about 12min), which was comparable with, or swifter than, that induced by cycloheximide. However, although after cycloheximide treatment the amount of immunotitrable ornithine decarboxylase decreased only slightly more slowly than the enzyme activity, diaminopropane injection did not decrease the amount of the immunoreactive protein, but, on the contrary, invariably caused a marked increase in the apparent amount of antigen, after some lag period. The diamine-induced increase in the amount of the immunoreactive enzyme protein could be totally prevented by a simultaneous injection of cycloheximide. These results are in accord with the hypothesis that various diamines may result in rapid formation of macromolecular inhibitors to ornithine decarboxylase in vivo, which, after combination with the enzyme, abolish the catalytic activity but at the same time prevent the intracellular degradation of the enzyme protein.

Stimulatory signals from the central nervous system for ornithine decarboxylase activity in the rat duodenal mucosa

1995 ◽  
Vol 2 (1) ◽  
pp. 25-28 ◽  
Author(s):  
Kazuma Fujimoto ◽  
Hidesuke Morita ◽  
Chika Matsunaga ◽  
Shin-ichi Ogata ◽  
Noriaki Furukawa ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Ornithine Decarboxylase ◽  
Duodenal Mucosa ◽  
Decarboxylase Activity ◽  
Ornithine Decarboxylase Activity ◽  
The Central Nervous System

scholarly journals Ornithine decarboxylase induction in cells stimulated to proliferate differs from that in continuously dividing cells

1980 ◽  
Vol 188 (2) ◽  
pp. 375-380 ◽  
Author(s):  
Anne E. Cress ◽  
Eugene W. Gerner
Keyword(s):  
Enzyme Activity ◽  
Dna Synthesis ◽  
Ornithine Decarboxylase ◽  
Chinese Hamster Ovary Cells ◽  
Time Interval ◽  
Decarboxylase Activity ◽  
Quiescent Cells ◽  
Ornithine Decarboxylase Activity ◽  
Dividing Cells ◽  
In Cells

Ornithine decarboxylase activity increases at least 4–5-fold before DNA synthesis both in synchronous cycling cells and in quiescent cells stimulated to proliferate. The purpose of our experiments was to test whether the transient peaks of ornithine decarboxylase activity in both growth situations were biochemically regulated in a similar manner. We found that the regulation of this particular enzyme activity is distinct in two ways. Firstly, the addition of 2mm-hydroxyurea will block the induction of ornithine decarboxylase in continuously dividing Chinese-hamster ovary cells, while having no effect on ornithine decarboxylase induction in stimulated quiescent cells. Hydroxyurea added after the induction occurs has no effect on the enzyme activity. The apparent half-life of the enzyme is not altered in cells treated with hydroxyurea. Hydroxyurea does not affect the enzyme directly, since incubation of cell homogenates with this drug results in no loss of measurable ornithine decarboxylase activity and hydroxyurea does not markedly alter general RNA- or protein-synthesis rates. The inactivation of ornithine decarboxylase activity by hydroxyurea does not resemble the loss of activity observed with a 90min treatment with spermidine. Thiourea, a less potent inhibitor of ribonucleoside diphosphate reductase, will also inhibit ornithine decarboxylase activity, but to a lesser extent. Secondly, the expression of ornithine decarboxylase in quiescent cells stimulated to proliferate is biphasic as these cells traverse G1 and enter S phase, whereas only one peak of activity is apparent in synchronous cycling G1-phase cells. The time interval between the first peak of ornithine decarboxylase activity and the onset of DNA synthesis is approx. 5h longer in non-dividing cells stimulated to proliferate than in continuously dividing cells. The results suggest that the regulation of ornithine decarboxylase activity is different in the two growth systems in that the induction of ornithine decarboxylase in continuously dividing cells occurs closer in time to DNA synthesis and is dependent on deoxyribonucleoside triphosphates.

scholarly journals Regulation of l-ornithine decarboxylase and S-adenosyl-l-methionine decarboxylase in rat ventral prostate and seminal vesicle

1977 ◽  
Vol 168 (3) ◽  
pp. 379-385 ◽  
Author(s):  
Kirsti Piik ◽  
Pirkko Rajamäki ◽  
Sujit K. Guha ◽  
Juhani Jänne
Keyword(s):  
Enzyme Activity ◽  
Seminal Vesicle ◽  
Ornithine Decarboxylase ◽  
Prostate Gland ◽  
Ventral Prostate ◽  
Rat Tissues ◽  
Decarboxylase Activity ◽  
Testosterone Treatment ◽  
Ornithine Decarboxylase Activity ◽  
Stimulation Of

1. The activities of l-ornithine decarboxylase (EC 4.1.1.17) and S-adenosyl-l-methionine decarboxylase (EC 4.1.1.50) were dramatically enhanced in both the ventral prostate and the seminal vesicle of castrated rats in response to androgenic stimulation. The time course of the stimulation of ornithine decarboxylase together with the quantitatively different response of adenosylmethionine decarboxylase to testosterone treatment in the prostate gland and seminal vesicle indicated that the enhancement in polyamine synthesis in the ventral prostate may reflect both cellular proliferation and the restoration of the secretory functions of the organ. In the seminal vesicle, however, the stimulation of the polyamine-biosynthetic pathway more closely resembled the pattern found in other rat tissues, such as regenerating liver, undergoing compensatory growth. 2. Ornithine decarboxylase activity in the ventral prostate and especially in the seminal vesicle of sexually mature rat was diminished in vivo by various short-chain diamines such as 1,2-diaminoethane, 1,3-diaminopropane and putrescine (1,4-diaminobutane). These diamines had no direct effect on the enzyme activity in vitro. 3. In contrast with the marginal decrease in ornithine decarboxylase activity produced by diaminoethane in the ventral prostate of non-castrated animals, repeated injections of the latter amine completely prevented the intense stimulation of the enzyme activity in the ventral prostate and seminal vesicle of castrated rats at 24h after the commencement of testosterone treatment. 4. The decrease in ornithine decarboxylase activity observed after injections of diamines (putrescine) in the ventral prostate was apparently associated with a similar decrease in the amount of immunoreactive protein as revealed by immunotitration of the enzyme with antiserum to rat ornithine decarboxylase.

scholarly journals Regulation of the expression of human ornithine decarboxylase gene and ornithine decarboxylase promoter-driven reporter gene in transgenic mice

1993 ◽  
Vol 292 (3) ◽  
pp. 927-932 ◽  
Author(s):  
M Halmekytö ◽  
J M Hyttinen ◽  
R Sinervirta ◽  
P Leppänen ◽  
J Jänne ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Transgenic Mice ◽  
Ornithine Decarboxylase ◽  
Reporter Gene ◽  
Phorbol Ester ◽  
Chloramphenicol Acetyltransferase ◽  
Decarboxylase Activity ◽  
Mrna Levels ◽  
Regenerating Liver ◽  
Ornithine Decarboxylase Activity

We have studied the regulation of the expression of ornithine decarboxylase with the aid of transgenic mice harbouring either functional human ornithine decarboxylase genes or the mouse ornithine decarboxylase promoter-driven chloramphenicol acetyltransferase fusion gene in their genome. We used three different stimuli which are well known to enhance ornithine decarboxylase activity in their appropriate target tissues: (i) testosterone in female kidney, (ii) a phorbol ester in epidermis and (iii) partial hepatectomy in liver. Endogenous mouse ornithine decarboxylase activity was strikingly stimulated in response to these treatments. Even though containing the 5′ flanking region of the mouse ornithine decarboxylase gene, known to possess full promoter activity, the chloramphenicol acetyltransferase reporter gene was entirely insensitive to any of these stimuli. The human transgene-derived ornithine decarboxylase activity in kidney was unaffected by testosterone treatment, but responded in skin to application of the phorbol ester and likewise was clearly enhanced in regenerating liver. Although mouse endogenous ornithine decarboxylase mRNA levels were distinctly elevated after testosterone, this treatment did not influence the accumulation of the human transgene-derived mRNA. The phorbol ester enhanced the accumulation of mouse endogenous ornithine decarboxylase mRNA and also that derived from the human transgene; however, the enzyme activity was stimulated in regenerating liver without appreciable changes in the levels of endogenous or transgene-derived message. Our present results strongly emphasize the central role of the coding sequence or ornithine decarboxylase gene in the induction of the enzyme activity.

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