Pharmacological characterization of histamine H3 receptors in isolated rabbit gastric glands

1992 ◽  
Vol 262 (1) ◽  
pp. G56-G61 ◽  
Author(s):  
A. Bado ◽  
L. Moizo ◽  
J. P. Laigneau ◽  
M. J. Lewin
Keyword(s):  
Acid Secretion ◽  
Histamine Release ◽  
Secretory Process ◽  
Dependent Manner ◽  
Gastric Glands ◽  
Pharmacological Characterization ◽  
H2 Antagonist ◽  
H3 Receptors ◽  
Dose Dependent

The effects of the specific H3 agonist (R)-alpha-methylhistamine (alpha-MeHA) and the specific H3 antagonist thioperamide were examined on histamine release and acid secretion [( 14C]-aminopyrine (AP) accumulation) by isolated rabbit gastric glands. Thioperamide significantly enhanced basal histamine release from the glands (+50% at 30 min for 10(-7) M thioperamide; P less than 0.01), and this increase was prevented by alpha-MeHA. Histamine-elicited AP accumulation was increased by 18% (P less than 0.05) by 10(-7) M thioperamide and decreased by 70% (P less than 0.01) by 10(-6) M of the H2 antagonist ranitidine. Thioperamide alone significantly enhanced AP accumulation in a dose-dependent manner, whereas alpha-MeHA had no effect of its own on this accumulation. Thioperamide stimulation of basal AP accumulation was not modified by ranitidine but was 50% decreased by alpha-MeHA. Furthermore, carbachol-induced AP accumulation was decreased by alpha-MeHA and increased by thioperamide; the latter effect was not blocked by ranitidine. These findings support that H3 receptors pharmacologically distinct from H2 receptors are involved in the regulation of histamine-stimulated acid secretion. They further suggest that these gastric H3 receptors occur in the gastric glands as 1) H3 autoreceptors located on the histamine-secreting cells and acting to downregulate histamine release from these cells and 2) H3 (or H3-like) receptors located on the parietal cell and regulating in a negative manner the acid secretory process.

Inhibition of acid secretion by the nonsteroidal anti-inflammatory drugs diclofenac and piroxicam in isolated gastric glands: analysis of a multifocal mechanism

2004 ◽  
Vol 286 (5) ◽  
pp. G711-G721 ◽  
Author(s):  
María Salvatella ◽  
Irma Rossi ◽  
Juan C. Del Valle ◽  
Yolanda Gutiérrez ◽  
Carmen Pereda ◽  
...  
Keyword(s):  
Acetylsalicylic Acid ◽  
Acid Secretion ◽  
Gastric Gland ◽  
Hydrolytic Activity ◽  
Acid Formation ◽  
Dependent Manner ◽  
Inhibitory Effects ◽  
Gastric Glands ◽  
Microsomal Membranes ◽  
Dose Dependent

In nonstimulated rabbit gastric glands, acetylsalicylic acid (10–500 μM) and indomethacin (3–300 μM) did not significantly modify the basal rate of acid secretion, whereas diclofenac and piroxicam (10–1,000 μM each) caused a marked and dose-dependent inhibitory effect (EC50 = 138 and 280 μM, respectively). In gastric glands stimulated by histamine (100 μM), diclofenac also reduced the rate of acid formation in a dose-dependent manner. In contrast, acetylsalicylic acid, indomethacin, and piroxicam exerted a biphasic effect; thus low concentrations (3–100 μM) of these three agents significantly increased the rate of histamine-stimulated acid secretion (10–20% over the corresponding control value) by a cAMP-independent mechanism, whereas higher concentrations reduced the rate of acid formation. With respect to underlying biochemical mechanisms that could mediate inhibitory effects of NSAIDs on gastric acid formation, it was observed that both diclofenac and piroxicam, but not acetylsalicylic acid or indomethacin, decreased the glandular content of ATP, inhibited hydrolytic activity of gastric gland microsomal H+-K+-ATPase, and reduced the rate of H+-K+-ATPase-dependent proton transport across microsomal membranes in a dose-dependent manner. Furthermore, diclofenac and piroxicam also significantly increased passive permeability of microsomal membranes to protons. In conclusion, our work shows that diclofenac and piroxicam cause a significant reduction in the rate of basal and histamine-stimulated acid formation in isolated rabbit gastric glands at concentrations that can be attained in the gastric lumen of patients treated with these drugs. Mechanisms involved in these inhibitory effects appear to be multifocal and include different steps of stimulus-secretion coupling.

Pharmacological characterization of a novel oestrogen antagonist, ZK 119010, in rats and mice

1991 ◽  
Vol 130 (3) ◽  
pp. 409-414 ◽  
Author(s):  
Y. Nishino ◽  
M. R. Schneider ◽  
H. Michna ◽  
E. von Angerer
Keyword(s):  
Dependent Manner ◽  
Adult Rats ◽  
Pharmacological Characterization ◽  
Once Daily ◽  
Uterine Growth ◽  
Steroidal Compound ◽  
Rats And Mice ◽  
Dose Dependent ◽  
Higher Doses

ABSTRACT The oestrogenic and antioestrogenic effects of a new non-steroidal compound ZK 119010(2-(4-hydroxyphenyl)-3-methyl-1-[6-(1-pyrrolidinyl)-hexyl]-indol-5-ol) were evaluated and compared with those of tamoxifen and ICI 164384. In immature mice, ZK 119010 administered once daily for 3 days (s.c.) inhibited the uterotrophic and vaginotrophic effect of oestradiol in a dose-dependent manner and was distinctly more potent than tamoxifen or ICI 164384 in exerting antioestrogenic effects. When antioestrogens in combination with oestradiol were administered once daily for 5 days to ovariectomized adult rats, ZK 119010 at lower doses (≤ 1 mg/kg) was slightly less effective than tamoxifen in inhibiting the uterotrophic effect of oestradiol. At the higher doses, however, ZK 119010 was strongly antioestrogenic, and ICI 164384 was less effective than ZK 119010 or tamoxifen. ZK 119010 at 10 mg/kg, like ICI 164384 at 30 mg/kg, caused an almost complete inhibition of the oestradiol-induced uterine growth in rats. The antioestrogenic effect of tamoxifen in rats was also limited by its inherent oestrogenic property. The oestrogenic activity of ZK 119010 was much below that of tamoxifen, whereas ICI 164384 did not show oestrogenicity. The present results indicate that ZK 119010 is a novel type of non-steroidal antioestrogen which has only a marginal oestrogenic effect in rats and mice. Such an antioestrogen may be useful for the treatment of oestrogen-sensitive diseases in man. Journal of Endocrinology (1991) 130, 409–414

Somatostatin inhibition of secretagogue and forskolin-stimulated gastric acid secretion

1988 ◽  
Vol 254 (4) ◽  
pp. G531-G537
Author(s):  
F. Michelangeli ◽  
M. C. Ruiz ◽  
C. L. Rodriguez ◽  
A. Pelacca
Keyword(s):  
Acid Secretion ◽  
Histamine Release ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Direct Stimulation ◽  
Histamine Stimulation ◽  
Ussing Chambers ◽  
Cyclic Monophosphate ◽  
Dose Dependent ◽  
Stimulation Of

The action of somatostatin (SS) on acid secretion and histamine release was studied in isolated gastric mucosa of toads mounted in Ussing chambers. SS inhibited H+ secretion and histamine release stimulated by cholinergic and gastrinergic secretagogues. Exogenous histamine stimulation of H+ secretion was blocked noncompetitively by SS in a dose-dependent manner. In mucosae maximally stimulated by histamine or forskolin and cimetidine, acetylcholine (ACh) and tetragastrin (TG) induced a direct stimulation of the oxyntopeptic cell not inhibited by SS. Indomethacin, an inhibitor of prostaglandin synthesis, did not prevent SS inhibition of histamine stimulation. Pretreatment with SS abolished forskolin stimulation of H+ secretion. SS induced a small inhibition of the stimulatory effect of N6, 2'-O-dibutyryladenosine 3',5'-cyclic monophosphate. These results suggest that SS inhibits acid secretion stimulated by secretagogues through different mechanisms: 1) inhibition of histamine release by ACh and TG, 2) inhibition of endogenous and exogenous histamine stimulation through a blockade of adenylate cyclase, and 3) an inhibitory effect subsequent to the synthesis of adenosine 3',5'-cyclic monophosphate. The direct activation of the oxyntopeptic cell by ACh and TG does not seem to be affected by somatostatin.

Production and utilization of monoclonal antibodies to human/rat corticotrophin-releasing factor-41

1990 ◽  
Vol 5 (2) ◽  
pp. 159-166 ◽  
Author(s):  
N. G. N. Milton ◽  
E. W. Hillhouse ◽  
S. A. Nicholson ◽  
C. H. Self ◽  
A. M. McGregor
Keyword(s):  
Monoclonal Antibodies ◽  
Enzyme Linked Immunosorbent Assay ◽  
Dependent Manner ◽  
Corticotrophin Releasing Factor ◽  
Tissue Extracts ◽  
Rat Pituitary ◽  
Hypothalamic Tissue ◽  
Dose Dependent

ABSTRACT Murine monoclonal antibodies against human/rat corticotrophin-releasing factor-41 (CRF-41) were produced and characterized for use in the immunological and biological characterization of CRF-41. Spleen cells from BALB/c mice immunized with CRF-41 conjugated to bovine γ-globulin were fused with a BALB/c-derived non-secretor X-63 myeloma line. Hybridomas were selected for CRF antibody production by enzyme-linked immunosorbent assay, and positive hybridomas cloned twice. Three monoclonal antibodies were obtained (KCHMB001, KCHMB002 and KCHMB003) and characterized as IgG1, IgG1 and IgG2a isotypes respectively, with affinity constants for rat CRF-41 of 30, 53 and 34 nmol/l respectively. All three monoclonal antibodies recognize an epitope contained between residues 34 and 41 of the human/rat sequence. The antibodies were able to neutralize the ACTH-releasing activity of rat CRF-41, applied to rat pituitary fragments in vitro, in a dose-dependent manner. Isoelectric focusing showed that KCHMB 003 detected bands of synthetic rat CRF-41 and rat [Met(O)21,38]-CRF-41 at pH 7·1 and 6·8 respectively. Use of KCHMB003 in a two-site enzyme-amplified immunoassay showed that this antibody recognizes both synthetic rat CRF-41 and immunoreactive CRF-41 in rat hypothalamic tissue extracts.

scholarly journals A Mechano-Activated Cell Reporter System as a Proxy for Flow-Dependent Endothelial Atheroprotection

2018 ◽  
Vol 23 (8) ◽  
pp. 869-876
Author(s):  
Bendix R. Slegtenhorst ◽  
Oscar R. Fajardo Ramirez ◽  
Yuzhi Zhang ◽  
Zahra Dhanerawala ◽  
Stefan G. Tullius ◽  
...  
Keyword(s):  
Vascular Endothelium ◽  
Critical Role ◽  
Green Fluorescence Protein ◽  
Dependent Manner ◽  
Reporter System ◽  
Health And Disease ◽  
Fluorescence Protein ◽  
Biomechanical Stimuli ◽  
Dose Dependent

The vascular endothelium plays a critical role in the health and disease of the cardiovascular system. Importantly, biomechanical stimuli generated by blood flow and sensed by the endothelium constitute important local inputs that are translated into transcriptional programs and functional endothelial phenotypes. Pulsatile, laminar flow, characteristic of regions in the vasculature that are resistant to atherosclerosis, evokes an atheroprotective endothelial phenotype. This atheroprotective phenotype is integrated by the transcription factor Kruppel-like factor-2 (KLF2), and therefore the expression of KLF2 can be used as a proxy for endothelial atheroprotection. Here, we report the generation and characterization of a cellular KLF2 reporter system, based on green fluorescence protein (GFP) expression driven by the human KLF2 promoter. This reporter is induced selectively by an atheroprotective shear stress waveform in human endothelial cells, is regulated by endogenous signaling events, and is activated by the pharmacological inducer of KLF2, simvastatin, in a dose-dependent manner. This reporter system can now be used to probe KLF2 signaling and for the discovery of a novel chemical-biological space capable of acting as the “pharmacomimetics of atheroprotective flow” on the vascular endothelium.

scholarly journals Isolation and Characterization of a Lectin-like Protein (SBLP) from the Dried Roots of Scutellaria baicalensis (Lamiaceae)

2018 ◽  
Vol 13 (12) ◽  
pp. 1934578X1801301
Author(s):  
Huiqin Wang ◽  
Guanzhen Gao ◽  
Lijing Ke ◽  
Jianwu Zhou ◽  
Pingfan Rao
Keyword(s):  
Anion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Scutellaria Baicalensis ◽  
Dependent Manner ◽  
Scutellaria Baicalensis Georgi ◽  
Isolation And Characterization ◽  
Pas Staining ◽  
Ph Range ◽  
Dose Dependent

A novel lectin-like protein with MW 63.2 kDa, designated as SBLP, has been isolated and characterized from the dried roots of Scutellaria baicalensis Georgi (Lamiaceae). SBLP was purified by ammonium sulfate precipitation and anion exchange chromatography. It is a glycoprotein according to a PAS staining assay and consisting of protein (86.0%) and sugar (14.0%). Its N-terminal amino acid sequence was determined as GSAVGFLY by Edman degradation. SBLP showed hemagglutinating activity against human and rooster erythrocytes, which were stable below 60°C and in the pH range of 4 −10. Furthermore, SBLP was found to be stimulated by Ca2+, Na+, Ba2+, Zn2+ ions, which suggested it was a metal-dependent lectin. SBLP inhibited the growth of Fusarium oxysporum f.sp. lycopersici and Alternaria eichhorniae in the a dose-dependent manner, and suppressed the proliferation of HepG2 tumor cells with an IC50 of 1.00 μM. This is the first report of a lectin from Radix Scutellariae.

scholarly journals Uric Acid Secretion from Adipose Tissue and Its Increase in Obesity

2013 ◽  
Vol 288 (38) ◽  
pp. 27138-27149 ◽  
Author(s):  
Yu Tsushima ◽  
Hitoshi Nishizawa ◽  
Yoshihiro Tochino ◽  
Hideaki Nakatsuji ◽  
Ryohei Sekimoto ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Uric Acid ◽  
Acid Secretion ◽  
Acid Production ◽  
Culture Medium ◽  
Dependent Manner ◽  
Obese Mice ◽  
Subsequent Increase ◽  
Dose Dependent ◽  
Uric Acid Secretion

Obesity is often accompanied by hyperuricemia. However, purine metabolism in various tissues, especially regarding uric acid production, has not been fully elucidated. Here we report, using mouse models, that adipose tissue could produce and secrete uric acid through xanthine oxidoreductase (XOR) and that the production was enhanced in obesity. Plasma uric acid was elevated in obese mice and attenuated by administration of the XOR inhibitor febuxostat. Adipose tissue was one of major organs that had abundant expression and activities of XOR, and adipose tissues in obese mice had higher XOR activities than those in control mice. 3T3-L1 and mouse primary mature adipocytes produced and secreted uric acid into culture medium. The secretion was inhibited by febuxostat in a dose-dependent manner or by gene knockdown of XOR. Surgical ischemia in adipose tissue increased local uric acid production and secretion via XOR, with a subsequent increase in circulating uric acid levels. Uric acid secretion from whole adipose tissue was increased in obese mice, and uric acid secretion from 3T3-L1 adipocytes was increased under hypoxia. Our results suggest that purine catabolism in adipose tissue could be enhanced in obesity.

scholarly journals Gene and cDNA cloning and characterization of the mouse V3/V1b pituitary vasopressin receptor

1999 ◽  
Vol 22 (3) ◽  
pp. 251-260 ◽  
Author(s):  
MA Ventura ◽  
P Rene ◽  
Y de Keyzer ◽  
X Bertagna ◽  
E Clauser
Keyword(s):  
Inositol Phosphate ◽  
Rank Order ◽  
Single Gene ◽  
Dependent Manner ◽  
Binding Studies ◽  
V1b Receptor ◽  
Competition Binding ◽  
Receptor Cdna ◽  
Dose Dependent

The gene of the mouse V3/V1b receptor was identified by homology cloning. One of the genomic clones contained the entire coding sequence. The cDNA presented high identity with rat (92%) and human (84%) sequences. Southern blot analysis indicated the existence of a single gene. Tissue distribution was studied by RT-PCR. The major site of expression was the pituitary. A faint signal was also present in hypothalamus, brain, adrenal, pancreas and colon. The mouse corticotroph cell line, AtT20, did not express the transcript. In order to confirm the identity of the sequence, the V3/V1b receptor cDNA was cloned and stably expressed in CHO-AA8 Tet-Off cells under the control of tetracycline. When transfected cells were treated with arginine vasopressin (AVP), inositol phosphate production increased in a dose-dependent manner, indicating that the V3/V1b receptor couples to phospholipase C. Moreover, AVP did not stimulate cAMP production. Binding studies with [3H]AVP indicated that the affinity of the mouse V3/V1b receptor (Kd=0.5 nM) is similar to that reported for rat and human receptors. The rank order of potency established in competition binding experiments with different analogues was representative of a V3/V1b profile, distinct from V1a and V2. However, significant differences were found between human and mouse receptors tested in parallel. Thus the pharmacology of V3/V1b receptors can not be transposed among different species.

Effect of catecholamines on somatostatin secretion by isolated perfused rat stomach

1981 ◽  
Vol 240 (3) ◽  
pp. E274-E278
Author(s):  
Y. Goto ◽  
M. Berelowitz ◽  
L. A. Frohman
Keyword(s):  
Acid Secretion ◽  
Gastric Acid Secretion ◽  
Gastric Acid ◽  
Inhibitory Effect ◽  
Dependent Manner ◽  
Rat Stomach ◽  
Beta Adrenergic ◽  
Somatostatin Secretion ◽  
Adrenergic Mechanism ◽  
Dose Dependent

The secretion of somatostatin-like immunoreactivity (SRIF-LI) by the isolated perfused rat stomach was studied in response to stimulation by catecholamines. Gastric SRIF-LI secretion was significantly stimulated in a dose-dependent manner by norepinephrine at 10(-6) and 10(-8) M, and the effect of norepinephrine (10(-8) M) was attenuated by the addition of propranolol (10(-6) M) but not of phentolamine (10(-6) M). SRIF-LI secretion was also stimulated by dopamine at concentrations of 10(-4) and 10(-6) M but not at 10(-8) M. The effect of dopamine (10(-6) M) was not altered by the addition of haloperidol (10(-4) to 10(-7)) or metoclopramide (10(-4) M), and bromocriptine (10(-6) M) was without effect on SRIF-LI secretion. These results suggest that gastric SRIF-LI secretion is stimulated by a beta-adrenergic mechanism and raise the possibility that gastric somatostatin contributes to the inhibitory effect of norepinephrine on gastric acid secretion.

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