Effects of dexamethasone on the activity of histidine decarboxylase, ornithine decarboxylase, and DOPA decarboxylase in rat oxyntic mucosa

1991 ◽  
Vol 69 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Masataka Araki ◽  
Mitsuo Nakamura ◽  
Seiichi Takenoshita ◽  
Hirokazu Shoda ◽  
Yukio Nagamachi ◽  
...  
Keyword(s):  
Ornithine Decarboxylase ◽  
Histidine Decarboxylase ◽  
Serum Gastrin ◽  
Single Injection ◽  
Dopa Decarboxylase ◽  
Peptic Ulcers ◽  
Dexamethasone Treatment ◽  
Oxyntic Mucosa ◽  
Significant Change ◽  
Stimulation Of

Since accelerated turnover of histamine in oxyntic mucosa may be an important factor in the pathogenesis of peptic ulcers, the effect of dexamethasone and other glucocorticoids on the activity of gastric histidine decarboxylase (HDC) was studied in the rat. The activity of HDC in rat oxyntic mucosa increased significantly after dexamethasone was injected s.c. to rats at doses larger than 0.4 mg/kg body weight. The maximum response of the HDC activity to dexamethasone (4 mg/kg) was observed 8 h after the treatment. The activity of ornithine decarboxylase (ODC) increased at 4 h, while that of DOPA decarboxylase showed no significant change throughout the 16-h period following a single injection of dexamethasone. The mucosal levels of histamine, putrescine, and spermidine rose significantly after the steroid treatment, while the spermine levels remained nearly constant. There was no sex difference in these responses to dexamethasone. Betamethasone showed nearly the same effects as dexamethasone on the decarboxylase activities and the mucosal levels of diamines. Serum gastrin levels showed no significant change for the first 4 h and then rose significantly 8 and 16 h after dexamethasone treatment. Pentagastrin (0.5 mg/kg) increased the HDC activity, while it showed no significant effect on either the mucosal ODC activity or levels of polyamines and histamine. These data suggest that dexamethasone influences the metabolism of histamine and polyamines in rat oxyntic mucosa both directly and via stimulation of gastrin release.Key words: dexamethasone, betamethasone, oxyntic mucosa, histidine decarboxylase, ornithine decarboxylase, DOPA decarboxylase.

Comparison between activation of ornithine decarboxylase and histidine decarboxylase in rat stomach

1996 ◽  
Vol 270 (3) ◽  
pp. G476-G486 ◽  
Author(s):  
X. Q. Ding ◽  
D. Chen ◽  
E. Rosengren ◽  
L. Persson ◽  
R. Hakanson
Keyword(s):  
Food Intake ◽  
Ornithine Decarboxylase ◽  
Histidine Decarboxylase ◽  
Serum Gastrin ◽  
Oral Treatment ◽  
Somatostatin Analogue ◽  
Rat Stomach ◽  
Oxyntic Mucosa ◽  
Serum Gastrin Concentration ◽  
Fasted Rats

We compared the responses of rat stomach ornithine decarboxylase (ODC) and histidine decarboxylase (HDC) to food intake, oral treatment with antisecretagogues, NaHCO3, and hypertonic NaCl, antrectomy, intravenous infusion of gastrin-17, the selective cholecystokinin (CCK)-B/gastrin receptor antagonist L-365,260, and the somatostatin analogue RC-160. The serum gastrin concentration and oxyntic mucosal ODC and HDC activities were higher in freely fed rats than in fasted rats. Food intake in fasted rats raised the serum gastrin concentration and the ODC and HDC activities. Ranitidine, omeprazole, and NaHCO3 raised the serum gastrin concentration and activated ODC and HDC. Hypertonic NaCl raised the ODC activity 200-fold, whereas circulating gastrin and HDC activity were increased only moderately. Infusion of gastrin-17 activated HDC but not ODC. L-365,260 prevented the activation of HDC but not of ODC in response to food intake and treatment with omeprazole, NaHCO3, or hypertonic NaCl. Antrectomy prevented the food- and omeprazole-evoked rise in oxyntic mucosal HDC activity but not the rise in ODC activity. RC-160 suppressed HDC activity after food intake and treatment with omeprazole, NaHCO3, or NaCl. In contrast, RC-160 suppressed omeprazole- and NaHCO3-evoked ODC activation but not that evoked by food intake or NaCl. The results support the view that HDC in the oxyntic mucosa is activated by gastrin and suppressed by somatostatin. The induction of ODC is not mediated by gastrin; ODC activation appears to be related to acid inhibition per se or to mucosal maintenance and repair; somatostatin, or rather the lack of it, might contribute to the induction of ODC after acid blockade. The mechanism behind the activation of rat stomach ODC seems to differ depending on the type of stimulus.

Effects of phorbol ester and dexamethasone treatment on histidine decarboxylase and ornithine decarboxylase in basophilic cells

2001 ◽  
Vol 61 (9) ◽  
pp. 1101-1106 ◽  
Author(s):  
Ignacio Fajardo ◽  
Jose L Urdiales ◽  
Miguel A Medina ◽  
Francisca Sanchez-Jimenez
Keyword(s):  
Ornithine Decarboxylase ◽  
Phorbol Ester ◽  
Histidine Decarboxylase ◽  
Dexamethasone Treatment

Gastrin regulates histidine decarboxylase activity and mRNA abundance in rat oxyntic mucosa

1994 ◽  
Vol 267 (2) ◽  
pp. G254-G258 ◽  
Author(s):  
A. K. Sandvik ◽  
R. Dimaline ◽  
R. Marvik ◽  
E. Brenna ◽  
H. L. Waldum
Keyword(s):  
Enzymatic Activity ◽  
Histidine Decarboxylase ◽  
Serum Gastrin ◽  
Mrna Abundance ◽  
Decarboxylase Activity ◽  
Oxyntic Mucosa ◽  
Trophic Effect ◽  
Ecl Cell ◽  
Release Histamine ◽  
Different Doses

Gastrin release histamine from the oxyntic mucosa, stimulates the enzymatic activity of histidine decarboxylase (HDC), increases HDC mRNA abundance, and has a trophic effect on the enterochromaffin-like (ECL) cell. In the present study, we examined the effect of exogenous gastrin on HDC activity and mRNA and the time scale of increase and decline of HDC activity and mRNA. Rats received intravenous infusion of gastrin-(1-17) in different doses or periods of time. Oxyntic mucosal HDC activity and mRNA abundance increased significantly with serum gastrin concentrations in the physiological range. The onset of response was rapid and maximal for both parameters after 2 h. Poststimulatory decrease was maximal 2 h after cessation of gastrin infusion. Those observations suggest that HDC enzymatic activity and mRNA abundance are important in meal-to-meal regulation of gastric secretion. Furthermore, HDC enzymatic activity and mRNA abundance varied in parallel, indicating that HDC mRNA abundance is important in the overall regulation of gastric mucosal HDC activity.

scholarly journals Contamination of erythropoietin by endotoxin: in vivo and in vitro effects on murine erythropoiesis

Blood ◽  
1979 ◽  
Vol 54 (1) ◽  
pp. 146-158 ◽  
Author(s):  
KS Zuckerman ◽  
PJ Quesenberry ◽  
J Levin ◽  
R Sullivan
Keyword(s):  
Significant Inhibition ◽  
Erythropoietic Activity ◽  
Limulus Amebocyte Lysate ◽  
Endogenous Erythropoietin ◽  
Significant Change ◽  
In Vitro Effects ◽  
Stimulation Of

Abstract Endotoxin was detected in all erythropoietin preparations tested and was removed from four lots, without loss of erythropoietic activity, by adsorption with limulus amebocyte lysate. Comparison of adsorbed (endotoxin-depleted) and nonadsorbed (endotoxin-containing) erythropoietin preparations demonstrated significant inhibition of CFU- e and BFU-e in vitro by nonadsorbed erythropoietin at concentrations higher than 0.25 U/ml and 2.0 U/ml, respectively. CFU-e and BFU-e were inhibited significantly by readdition in vitro of 10(-5)-10(-3) mug of endotoxin per unit of limulus-adsorbed erythropoietin. Administration of saline or 6 U of nonadsorbed or adsorbed erythropoietin twice a day for 4 days of CF1 mice resulted in reticulocyte counts of 2.1%, 9.9%, and 15.9%, respectively. Nonadsorbed erythropoietin resulted in a 29% decrease in erythropoiesis, a 42% decrease in CFU-e, and a 16% increase in granulopoiesis in the marrow, whereas adsorbed erythropoietin caused a 28% increase in erythropoiesis, no significant change in CFU-e and a 19% decrease in granulopoiesis in the marrow. Both preparations resulted in marked increases in splenic erythropoiesis and granulopoiesis. The effects of adsorbed erythropoietin are similar to those produced following stimulation of hematopoiesis by endogenous erythropoietin. Hemopoietic changes induced by nonadsorbed erythropoietin in vivo and in vitro are affected substantially by contamination of the erythropoietin preparations with endotoxin.

Lafutidine-induced stimulation of mucin biosynthesis mediated by nitric oxide is limited to the surface mucous cells of rat gastric oxyntic mucosa

Life Sciences ◽  
1998 ◽  
Vol 62 (16) ◽  
pp. PL259-PL264 ◽  
Author(s):  
Takafumi Ichikawa ◽  
Kazuhiko Ishihara ◽  
Katsunori Saigenji ◽  
Kyoko Hotta
Keyword(s):  
Nitric Oxide ◽  
Mucous Cells ◽  
Oxyntic Mucosa ◽  
Stimulation Of

Regulation of rat stomach histidine decarboxylase activity by the serum gastrin concentration

1973 ◽  
Vol 3 (3) ◽  
pp. 178-179 ◽  
Author(s):  
R. Håkanson ◽  
G. Liedberg ◽  
J. Oscarson ◽  
J. F. Rehfeld ◽  
F. Stadil
Keyword(s):  
Histidine Decarboxylase ◽  
Serum Gastrin ◽  
Decarboxylase Activity ◽  
Rat Stomach ◽  
Serum Gastrin Concentration ◽  
Histidine Decarboxylase Activity

scholarly journals Induction of dopa (3,4-dihydroxyphenylalanine) decarboxylase in blowfly integument by ecdysone. A demonstration of synthesis of the enzyme de novo

1975 ◽  
Vol 146 (1) ◽  
pp. 121-126 ◽  
Author(s):  
E G Fragoulis ◽  
C E Sekeris
Keyword(s):  
Enzyme Activity ◽  
Steroid Hormones ◽  
De Novo ◽  
Steroid Hormone ◽  
Dopa Decarboxylase ◽  
Double Labelling ◽  
Labelling Technique ◽  
Immune Precipitation ◽  
Enzyme Molecules ◽  
Stimulation Of

The activity of the enzyme dopa (3,4-dihydroxyphenylalanine) decarboxylase, present in the epidermis cells of blowfly larvae, increases during the late third instar under the influence of the steroid hormone, ecdysone. By using the double-labelling technique and immune precipitation with univalent antibody to dopa decarboxylase, we demonstrated that the increase in enzyme activity was due to a stimulation of synthesis of enzyme molecules de novo. In this respect, the action of ecdysone is similar to the action of other steroid hormones.

Rat histidine decarboxylase promoter is regulated by gastrin through a protein kinase C pathway

1996 ◽  
Vol 270 (4) ◽  
pp. G619-G633 ◽  
Author(s):  
M. Hocker ◽  
Z. Zhang ◽  
D. A. Fenstermacher ◽  
S. Tagerud ◽  
M. Chulak ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Time Course ◽  
Histidine Decarboxylase ◽  
Peptide Hormone ◽  
Direct Stimulation ◽  
Gastric Glands ◽  
Kinase C ◽  
Translational Start ◽  
Stimulation Of

The enzyme L-histidine decarboxylase (HDC; EC 4.1.1.22), which converts L-histidine to histamine, plays a key role in the regulation of acid secretion. In the rat and human stomach, the peptide hormone gastrin appears to be one of the main regulators of HDC expression. In rats, marked elevation of gastric HDC mRNA abundance was observed within 12 h after induction of hypergastrinemia by a single injection of the proton-pump blocker omeprazole. In situ hybridization revealed that HDC expression occurred in the basal third of gastric glands where enterochromaffin-like cells are localized. To study the regulation of HDC gene transcription, 1,291 nucleotides of the 5'-flanking region of the rat HDC gene and the noncoding portion of exon 1 were cloned and sequenced. Gastrin and cholecystokinin (CCK) octapeptide equipotently stimulated the transcriptional activity of the rat HDC promoter three- to fourfold, and deletion analysis revealed the presence of a gastrin response element within 201 nucleotides upstream of the translational start site. Time-course studies revealed maximal activation of the HDC promoter after 12-36 h. Direct stimulation of protein kinase C (PKC) with the phorbol ester phorbol 12-myristate 13-acetate (PMA) substantially elevated rat HDC promoter activity, whereas induction of Ca2+ -dependent signaling pathways with thapsigargin was without effect. Downregulation or blockade of PKC abolished the effects of gastrin and PMA on the HDC promoter. These data indicate that stimulation of the CCK-B/gastrin receptor activates the rat HDC promoter in a time- and dose-dependent fashion and that this effect is primarily mediated via a PKC-dependent signaling pathway. Use of HDC as a model gene will allow further investigation of the intracellular pathways that are involved in gastrin-dependent gene regulation.

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