Identification of α2-adrenoceptors and non-adrenergic idazoxan binding sites in rabbit colon epithelial cells

Senard, Jean‐Michel; Langin, Dominique; Estañ, Luis; Paris, Hervé

doi:10.1016/0014-2999(90)94096-g

Cited by 28 publications

(18 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Estan et al (1990) showed up-regulation of platelet CX2-adrenoceptors with no change in adipocyte a2-adrenoceptors in dogs treated with reserpine. Similar discrepancies can be found after treatment with a2-adrenoceptor agonists or exposure to high levels of catecholamines: some studies showed X2-adrenoceptor downregulation in human (Brodde, 1982) and rabbit (Deighton et al, 1988b) platelets and desensitization after exposure to high levels of noradrenaline (Deighton et al, 1988a), whereas others observed no change (Hollister et al, 1983;Valet et al, 1989 Langin et al, 1990a) Senard et al, 1990). It was first suggested that NAIBS might be closely related to a2-adrenoceptors .…”

mentioning

confidence: 63%

“…First, one could suggest that the a2-adrenoceptor subtype in the studied tissue can explain these tissue differences. However, this explanation does not hold since in the rabbit, only the a2A-subtype was described in the tissues concerned (Deighton et al, 1988a;Senard et al, 1990). Differences in x2-adrenoceptor metabolism (t112) depending on the tissues can also be considered.…”

Section: Resultsmentioning

confidence: 99%

“…Introduction a2-Adrenoceptors are the initial recognition sites on a great variety of catecholamine responsive target cells and have been widely studied in three different tissues, platelet, adipose tissue and colon, where their function is the reduction of aggregation velocity (Galitzky et al, 1990b), antilipolysis (Taouis et al, 1988) and probably the increase in fluid and electrolyte (Cl-and Na') absorption (Nakaki et al, 1982;Senard et al, 1990) respectively.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Effect of a 7‐day treatment with idazoxan and its 2‐methoxy derivative RX 821001 on α₂‐adrenoceptors and non‐adrenoceptor idazoxan binding sites in rabbits

Portillo

Reverte

Langin

et al. 1991

British J Pharmacology

View full text Add to dashboard Cite

show abstract

mentioning

confidence: 63%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Effect of a 7‐day treatment with idazoxan and its 2‐methoxy derivative RX 821001 on α₂‐adrenoceptors and non‐adrenoceptor idazoxan binding sites in rabbits

Portillo

Reverte

Langin

et al. 1991

British J Pharmacology

View full text Add to dashboard Cite

show abstract

“…Moreover, we have assessed the effects of a 2 antagonists in this regard. Yohimbine, a selective a 2 adrenoceptor antagonist (Goldberg and Robertsson, 1983) with very low affinity for I 1 binding sites (I 1 /a 2 affinity ratio ¼ 0.01; Ernsberger et al, 1987Ernsberger et al, , 1992Hamilton et al, 1988;Senard et al, 1990), with a dose of 0.005 mg/kg is incapable of affecting place preference or altering morphine CPP; however, it completely blocks the potentiating effect of agmatine on morphineinduced place preference. Yohimbine with higher doses is shown to induce CPA (File, 1986) and it tends to limit the place preference induced by morphine (Morales et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

Agmatine Potentiates Morphine-Induced Conditioned Place Preference in Mice: Modulation by Alpha(2)-Adrenoceptors

Tahsili-Fahadan

Yahyavi-Firouz-Abadi

Khoshnoodi

et al. 2005

Neuropsychopharmacol

View full text Add to dashboard Cite

The effects of agmatine, an endogenous polyamine metabolite formed by decarboxylation of L-arginine, and its combination with morphine on conditioned place preference (CPP) has been investigated in male mice. Our data show that subcutaneous administration of morphine (1-7.5 mg/kg) significantly increases the time spent in the drug-paired compartment in a dose-dependent manner. Intraperitoneal administration of agmatine (1-40 mg/kg) alone does not induce either CPP or conditioned place aversion, while combination of agmatine and subeffective doses of morphine leads to potent rewarding effects. Lower doses of morphine (0.1, 0.05, and 0.01 mg/kg) are able to induce CPP in mice pretreated with agmatine 1, 5, and 10 mg/kg, respectively. Concomitant intraperitoneal administration of UK 14 304 (0.5 mg/kg), a highly selective a 2 -agonist, with per se noneffective dose of morphine (0.5 mg/kg) and also its combination with noneffective doses of agmatine (1 mg/kg) plus morphine (0.05 mg/kg) produces significant CPP. UK 14 304 (0.05, 0.5 mg/kg) alone, or in combination with agmatine (1, 5 mg/kg) have had no effect. We have further investigated the possible involvement of the a 2 -adrenoceptors in the potentiating effect of agmatine on morphine-induced place preference. Selective a 2 -antagonists, yohimbine (0.005 mg/kg) and RX821002 (0.1, 0.5 mg/kg), block the CPP induced by concomitant administration of agmatine (5 mg/kg) and morphine (0.05 mg/kg). Yohimbine (0.001-0.05 mg/kg) or RX821002 (0.05-0.5 mg/kg) alone or in combination with morphine (0.05 mg/kg) or agmatine (5 mg/kg) fail to show any significant place preference or aversion. Our results indicate that pretreatment of animals with agmatine enhances the rewarding properties of morphine via a mechanism which may involve a 2 -adrenergic receptors.

show abstract

“…Concerning the gastrointestinal (GI) tract, radioligand binding studies provided evidence for the presence of IRs in the stomach and intestines of different mammals (Houi et al 1987;Molderings et al 1998;Senard et al 1990;Wikberg et al 1991). CDS and agmatine were also identified in the GI tract (Meeley et al 1992;Raasch et al 1995), in fact, the highest concentrations of agmatine were measured in the stomach and intestines among all tissues in the rat (Raasch et al 1995).…”

Section: Introductionmentioning

confidence: 99%

Analysing the effect of I1 imidazoline receptor ligands on DSS-induced acute colitis in mice

et al. 2016

View full text Add to dashboard Cite

Imidazoline receptors (IRs) have been recognized as promising targets in the treatment of numerous diseases, and moxonidine and rilmenidine, agonists of I1-IRs are widely used as antihypertensive agents. Some evidence suggests that IR ligands may induce anti-inflammatory effects acting on I1-IRs or other molecular targets, which could be beneficial in patients with inflammatory bowel disease (IBD). On the other hand, several IR ligands may stimulate also alpha2-adrenoceptors, which was earlier shown to inhibit, but in more recent studies to rather aggravate colitis. Hence, this study aimed to analyse for the first time the effect of various I1-IR ligands on intestinal inflammation. Colitis was induced in C57BL/6 mice by adding dextran sulfate sodium (DSS) to the drinking water for 7 days. Mice were treated daily with different IR ligands; moxonidine and rilmenidine (I1-IR agonists), AGN 192403 (highly selective I1-IR ligand, putative antagonist), efaroxan (I1-IR antagonist), as well as with the endogenous IR agonists agmatine and harmane. It was found that moxonidine and rilmenidine at clinically relevant doses, similarly to the other IR ligands, do not have a significant impact on the macroscopic and histological signs of DSS-evoked inflammation. Likewise, colonic myeloperoxidase and serum interleukin-6 levels remained unchanged in response to these agents. Thus, our study demonstrates that imidazoline ligands do not influence significantly the severity of DSS-colitis in mice and suggest that they probably neither affect the course of IBD in humans. However, the translational value of these findings needs to be verified with other experimental colitis models and human studies.

show abstract

Identification of α2-adrenoceptors and non-adrenergic idazoxan binding sites in rabbit colon epithelial cells

Cited by 28 publications

References 26 publications

Effect of a 7‐day treatment with idazoxan and its 2‐methoxy derivative RX 821001 on α₂‐adrenoceptors and non‐adrenoceptor idazoxan binding sites in rabbits

Effect of a 7‐day treatment with idazoxan and its 2‐methoxy derivative RX 821001 on α₂‐adrenoceptors and non‐adrenoceptor idazoxan binding sites in rabbits

Agmatine Potentiates Morphine-Induced Conditioned Place Preference in Mice: Modulation by Alpha(2)-Adrenoceptors

Analysing the effect of I1 imidazoline receptor ligands on DSS-induced acute colitis in mice

Contact Info

Product

Resources

About

Identification of α2-adrenoceptors and non-adrenergic idazoxan binding sites in rabbit colon epithelial cells

Cited by 28 publications

References 26 publications

Effect of a 7‐day treatment with idazoxan and its 2‐methoxy derivative RX 821001 on α2‐adrenoceptors and non‐adrenoceptor idazoxan binding sites in rabbits

Effect of a 7‐day treatment with idazoxan and its 2‐methoxy derivative RX 821001 on α2‐adrenoceptors and non‐adrenoceptor idazoxan binding sites in rabbits

Agmatine Potentiates Morphine-Induced Conditioned Place Preference in Mice: Modulation by Alpha(2)-Adrenoceptors

Analysing the effect of I1 imidazoline receptor ligands on DSS-induced acute colitis in mice

Contact Info

Product

Resources

About

Effect of a 7‐day treatment with idazoxan and its 2‐methoxy derivative RX 821001 on α₂‐adrenoceptors and non‐adrenoceptor idazoxan binding sites in rabbits

Effect of a 7‐day treatment with idazoxan and its 2‐methoxy derivative RX 821001 on α₂‐adrenoceptors and non‐adrenoceptor idazoxan binding sites in rabbits