scholarly journals Studies on sex-organ development. Effect of hormones on ornithine decarboxylase activity in the developing chick ovary

1980 ◽  
Vol 188 (2) ◽  
pp. 313-319 ◽  
Author(s):  
Ching Sung Teng ◽  
Christina T. Teng
Keyword(s):  
Enzyme Activity ◽  
Ornithine Decarboxylase ◽  
Early Stage ◽  
Optimal Dose ◽  
Embryonic Stage ◽  
Early Developmental Stage ◽  
Decarboxylase Activity ◽  
Culture Techniques ◽  
Ornithine Decarboxylase Activity

The response of ornithine decarboxylase activity to hormones in the embryonic left ovary was measured throughout the stages of development. During the early stage of ovarian development (9th day of incubation), the ornithine decarboxylase activity (in terms of pmol CO2/30min per mg of protein) was high (766); it decreased from the 10th to the 12th day (575–239), increased slightly from the 13th to the 15th day (306) and finally fell to a low value (192–20) from the 18th day of development to birth. Administration of an optimal dose of oestrogen to the 9–10-day embryo stimulated the ovarian ornithine decarboxylase activity by 48–53%. If the same dose of oestrogen was administered to the 15–18-day embryo, the ovarian enzyme activity was suppressed by 32–43%. This biphasic response to oestrogen for enzyme induction is characteristic of the developing ovary and is not observed in other genital organs of the chick. In the early developmental stage (9–10th day) testosterone has no effect on ovarian ornithine decarboxylase activity, but in the late stage testosterone inhibits the activity by 41%. Organ culture techniques have been used to test the ovarian response to lutropin (luteinizing hormone). Lutropin stimulated ornithine decarboxylase activity by approx. 99–155% in the ovary of the early embryonic stage (10–13th day), and by 175–200% in the ovary of the late embryonic stage (15–18th day). The alteration in enzyme activity in the ovary as assayed in vitro during development is not due to the effect of the size of the endogenous ornithine pool. The relationship of ornithine decarboxylase activity to the morphological and biochemical changes in the developing ovary is discussed.

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.

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 Studies on sex-organ development. Oestrogenic effect on ornithine decarboxylase activity in the differentiating Müllerian ducts and other organs of the chick embryo

1978 ◽  
Vol 176 (1) ◽  
pp. 143-149 ◽  
Author(s):  
C S Teng ◽  
C T Teng
Keyword(s):  
Enzyme Activity ◽  
Ornithine Decarboxylase ◽  
Decarboxylase Activity ◽  
Mullerian Duct ◽  
Stages Of Development ◽  
Müllerian Duct ◽  
Mullerian Ducts ◽  
The Right ◽  
The Brain

The activity of ornithine decarboxylase in the differentiating left and right Müllerian ducts was assayed and compared with that in other embryonic organs, i.e. the liver and the brain throughout the stages of development. In general the enzyme activity was high in the early stages and decreased extensively in the late stages of development. Specifically, in the left and righ Müllerian ducts, the enzyme activity was high from day 8 to day 9 of incubation. In the right duct the enzyme activity started to decline on day 9 and then continuously decreased to an almost undetectable value on day 18 of incubation. In the left duct the enzyme activity also decreased slightly from day 9 to day 12; however, it increased from day 13 to day 15 and finally decreased to a constant value from day 18 until hatching. The alteration in enzyme activity in the Müllerian duct as assayed in vitro during development is not due to the effect of the size of the endogenous ornithine pool. When the enzyme activity was subjected to oestrogen stimulation, an increase of 5–10-fold for the left duct and of 5–3-fold for the right duct was observed during the course of development. No such stimulation was observed with the treatment of progesterone. Testosterone consistently caused a 25–30% inhibition of the enzyme activity in the Müllerian duct. Oestrogen slightly stimulated the enzyme activity in the developing liver but inhibited that of the brain. The concentration of the three polyamines measured in the Müllerian duct corresponds to the activity of the enzyme determined.

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 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.

Stimulation of rat ovarian ornithine decarboxylase in vitro by hCG, amino acids and bovine serum albumin

1980 ◽  
Vol 94 (4) ◽  
pp. 571-576 ◽  
Author(s):  
Kirsti Käpyaho
Keyword(s):  
Amino Acids ◽  
Bovine Serum Albumin ◽  
Cyclic Amp ◽  
Serum Albumin ◽  
Ornithine Decarboxylase ◽  
Bovine Serum ◽  
Defined Medium ◽  
Decarboxylase Activity ◽  
Ornithine Decarboxylase Activity

Abstract. Rat ovarian ornithine decarboxylase activity could be stimulated in vitro by a variety of factors, which apparently have different modes of action. Ovarian cells prepared from pre-pubertal rats by collagenase dispersion exhibited a low but detectable ornithine decarboxylase activity after a 6-h incubation in a defined medium. The enzyme activity was markedly enhanced in vitro by hCG, which also produced increased accumulation of cyclic AMP and stimulated the secretion of progesterone. In addition to the gonadotrophin, ovarian ornithine decarboxylase activity was strikingly stimulated by some non-essential amino acids, and especially by bovine serum albumin. While markedly enhancing ornithine decarboxylase activity, none of the latter additions increased the accumulation of cyclic AMP or enhanced the secretion of progesterone. Bovine serum albumin enhanced powerfully ornithine decarboxylase activity in vitro at very small concentrations (from 0.75 μm). The half-life of the enzyme remained unchanged (26—28 min) upon stimulation indicating that the stimulation mechanism did not involve any stabilization of the enzyme.

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