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1.
Background
Constitutive (agonist-independent) activity is a prerogative of many G protein-coupled receptors (GPCRs) including α1-adrenoceptors (α1-ARs). Inhibition of such an activity at α1-AR subtypes by antagonists with negative efficacy is difficult to be adequately tested.Methods
In the present experimental approach, we compared the activity of three calcium channel blockers (nifedipine, diltiazem and verapamil) and of three potent benzodioxane-based α1-AR antagonists, differing for subtype selectivity and inverse agonist properties, in producing smooth muscle relaxation and negative inotropy under the same test conditions. We selected, as benzodioxane derivatives, (S)-WB4101, inverse agonist with slight α1A/α1B-α1D AR selectivity, and two previously developed analogues. Both of these are potent antagonists at α1D-AR, that is the α1- AR subtype suspected of the highest susceptibility to inverse agonists for its high degree of basal activity, but only one is inverse agonist.Results
We found that all the three benzodioxane-related α1-AR antagonists have significant intrinsic relaxant activity on non-vascular smooth muscle and moderate negative inotropic effect, while they do not relax aorta. Their potency is always lower than that of three calcium channel blockers.Conclusions
Intrinsic myorelaxant and negative inotropic activity of the three benzodioxane-based α1-AR antagonist is related neither to a particular profile of α1-AR subtype selectivity nor to whether or not being an inverse agonist, but it parallels the calcium antagonists effects indicating a direct interaction of the three α1-AR antagonists with L-type Ca2+ channels. 相似文献2.
Background and purpose:
Previous studies have suggested a regulation of 5-hydroxytryptamine (5-HT) neurons by the endocannabinoid system. The aim of our work was to examine the effect of two CB1 receptor antagonists, SR141716A (rimonabant, Sanofi-Synthélabo Recherche, Montpellier, France) and N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251, Tocris Cookson, Bristol, UK), on the firing rate of dorsal raphe nucleus (DRN) neurons.Experimental approach:
Single-unit extracellular recordings were performed to study the effect of CB1 receptor antagonists in slices of the DRN from rat brain.Key results:
Rimonabant (1 µM) and AM251 (1 µM) decreased the firing rate of about 50% of all the recorded DRN 5-HT cells. The GABAAreceptor antagonist picrotoxin (20 µM) (Sigma) prevented and also reversed the inhibitory effect of rimonabant (1 µM) and AM251 (1 µM), suggesting that CB1 receptors regulate 5-HT neurons through the GABAergic system. However, the CB1/CB2 receptor agonist R-(+)-[2,3-dihydro-5-methyl-3-[(morpholinyl)-methyl]pyrrolol[1,2,3-de]-1,4-benzoxazinyl]-(1-naphthalenyl) methanone mesylate salt (10 µM) (WIN55212-2, Sigma, St. Louis, MO, USA) failed to change the firing activity of non-5-HT (presumably GABAergic) neurons in the DRN. The endocannabinoid N-(2-hydroxyethyl)-5Z,8Z,11Z,14Z-eicosatetraenamide (anandamide, Tocris Cookson) (10 µM) also inhibited the firing activity of a number of 5-HT neurons, but this inhibition was not blocked by rimonabant (1 µM) or AM251 (1 µM), and the stable analogue R-(+) N-(2-hydroxy-1methylethyl)-5Z,8Z,11Z,14Z-eicosatetraenamide (methanandamide, Tocris Cookson) (10 µM) did not mimic this effect. The selective CB1 receptor agonist arachidonoyl-2-chloroethylamide (ACEA) (1 µM) only slightly increased the firing rate of DRN 5-HT cells.Conclusions and implications:
These results suggest a tonic/constitutive regulation of DRN 5-HT neurons by the endocannabinoid system, which may occur through a CB1 receptor-mediated inhibition of the GABAergic system. The inhibitory effect of anandamide may be mediated through a CB1 receptor-independent mechanism. 相似文献3.
CL Limebeer VK Vemuri H Bedard ST Lang KP Ossenkopp A Makriyannis LA Parker 《British journal of pharmacology》2010,161(2):336-349
BACKGROUND AND PURPOSE
Cannabinoid CB1 receptor antagonists/inverse agonists, potentiate toxin-induced nausea and vomiting in animal models. Here, we sought to determine if this potentiated nausea was mediated by inverse agonism or neutral antagonism of the CB1 receptor, and if the potentiated nausea would be produced by intracerebroventricular (icv) administration of an inverse agonist.EXPERIMENTAL APPROACH
The conditioned gaping model of nausea in rats was used to compare the CB1 receptor antagonist/inverse agonist, AM251, and the CB1 receptor neutral antagonists, AM6527 (centrally and peripherally active) and AM6545 (peripherally active), in potentiating conditioned gaping produced by lithium chloride (LiCl) solution. The effect of icv (lateral ventricle and 4th ventricle) administration of AM251 on LiCl-induced gaping in this model was also evaluated.KEY RESULTS
At a dose that did not produce conditioned gaping on its own, systemically administered AM251 (1.25 mg·kg−1) potentiated LiCl-induced conditioned gaping and reduced sucrose palatability; however, even doses as high as 8 mg·kg−1 of AM6545 and AM6527 neither potentiated LiCl-induced conditioned gaping nor reduced sucrose palatability. Infusions of AM251 into the lateral ventricles (1.25, 12.5 and 125 µg) or the 4th ventricle (2.5, 12.5 and 125 µg) did not potentiate LiCl-induced conditioned gaping reactions, but all doses attenuated saccharin palatability during the subsequent test.CONCLUSIONS AND IMPLICATIONS
Inverse agonism, but not neutral antagonism, of CB1 receptors potentiated toxin-induced nausea. This effect may be peripherally mediated or may be mediated centrally by action on CB1 receptors, located distal to the cerebral ventricles. 相似文献4.
BACKGROUND AND PURPOSE
We have investigated how pre-incubating hCB2 CHO cells with the CB2 receptor antagonists/inverse agonists, AM630 and SR144528, affects how these and other ligands target hCB2 receptors in these cells or their membranes.EXPERIMENTAL APPROACH
We tested the ability of AM630, SR144528 and of the CB1/CB2 receptor agonists, CP55940 and R-(+)-WIN55212, to modulate forskolin-stimulated cAMP production in hCB2 CHO cells or [35S]-GTPγS binding to membranes prepared from these cells, or to displace [3H]-CP55940 from whole cells and membranes. Assays were also performed with the CB2 receptor partial agonist, Δ9-tetrahydrocannabivarin. Some cells were pre-incubated with AM630 or SR144528 and then washed extensively.KEY RESULTS
AM630 behaved as a low-potency neutral competitive antagonist in AM630-pre-incubated cells, a low-potency agonist in SR144528-pre-incubated cells, and a much higher-potency inverse agonist/antagonist in vehicle-pre-incubated cells. AM630 pre-incubation (i) reduced the inverse efficacy of SR144528 without abolishing it; (ii) increased the efficacy of Δ9-tetrahydrocannabivarin; and (iii) did not affect the potency with which AM630 displaced [3H]-CP55940 from whole cells or its inverse agonist potency and efficacy in the [35S]-GTPγS membrane assay.CONCLUSIONS AND IMPLICATIONS
These results suggest that AM630 is a protean ligand that can target a constitutively active form of the hCB2 receptor (R*) with low affinity to produce agonism or neutral antagonism and a constitutively inactive form of this receptor (R) with much higher affinity to produce inverse agonism, and that the constitutive activity of whole cells is decreased less by pre-incubation with AM630 than with the higher-efficacy inverse agonist, SR144528.LINKED ARTICLES
This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7 相似文献5.
Yueh-Lun Lee Ling-Heng Hsu Yueh-Hsiung Kuo Chen-Chen Lee 《Pharmacological reports : PR》2019,71(2):194-200
Background
Caffeic amides are derivatives of caffeic acid, which have antioxidant and anti-inflammatory properties, and high in vivo stability. The therapeutic effect of caffeic amides on allergic diseases, and especially on the maturation of bone marrow-derived dendritic cells (BM-DCs), remains unclear. In this study, we investigated the therapeutic potential of caffeic amides on allergic diseases by evaluating the maturation of DCs and evaluated their potential in inducing the differentiation of TH2 cells.Methods
BM-DCs isolated from BALB/c mice were treated with different caffeic amide derivatives for 48?h and the expression of surface markers was analyzed by flow cytometry. The differentiation of CD4+ T cells was detected by the 5-bromo-2-deoxyuridine (BrdU) incorporation assay and cytokine production was analyzed by ELISA.Results
Our results showed that among the six caffeic amides tested herein, only 36?M significantly inhibited the antigen-induced maturation of DCs associated with the expression of CD80, CD86, and major histocompatibility complex II (VC ovalbumin (OVA)+ thymic stromal lymphopoietin (TSLP) vs. 36?M OVA?+?TSLP). Additionally, the isolation and co-culture of antigen-specific CD4+ T cells with 36?M-treated BM-DCs suppressed the antigen-specific differentiation of TH2 cells.Conclusion
Among the six caffeic amides tested herein, 36?M (N-octyl caffeamide) might possess therapeutic potential for allergic diseases. 相似文献6.
Background
The osmolyte and antioxidant taurine plays an important role in regulation of cellular volume, oxidative status and Ca2+-homeostasis. Taurine uptake in human cells is regulated by the Na+- and Cl?-dependent taurine transporter TauT. In order to gain deeper structural insights about the substrate binding pocket of TauT, a HEK293 cell line producing a GFP-TauT fusion protein was generated.Methods
Transport activity was validated using cell-based [3H]-taurine transport assays. We determined the Km and IC50 values of taurine, β-alanine and γ-aminobutyrate. Additionally we were able to identify structurally similar compounds as potential new substrates or inhibitors of the TauT transporter. Substrate induced cytotoxicity was analyzed using a cell viability assay.Results
In this study we show competitive effects of the 3-pyridinesulfonate, 2-aminoethylhydrogen sulfate, 5-aminovalerate, β-aminobutyrate, piperidine-4-sulfonate, 2-aminoethylphosphate and homotaurine. We demonstrate that taurine uptake can be inhibited by a phosphate. Furthermore our studies revealed that piperidine-4-sulfonate interacts with TauT with a higher affinity than γ-aminobutyrate and imidazole-4-acetate.Conclusion
We propose that piperidine-4-sulfonate may serve as a potential lead structure for the design of novel drug candidates required for specific modulation of the TauT transporter in therapy of neurodegenerative diseases. 相似文献7.
Oliver P Keown Timothy J Winterburn Cherry L Wainwright Sandra M Macrury Ilene Neilson Fiona Barrett Stephen J Leslie Ian L Megson 《British journal of clinical pharmacology》2010,70(2):180-188
AIMS
Cannabinoid receptor-1 (CB1) antagonists suppress appetite and induce weight loss. Direct antagonism of CB1 receptors on platelets might be an additional benefit for CB1 antagonists, but the role of CB1 receptors in platelets is controversial. We tested the hypothesis that the endocannabinoid, 2-arachidonyl glycerol (2-AG), induces platelet aggregation by a COX-mediated mechanism rather than through CB1 receptor activation, in blood obtained from healthy volunteers and patients with coronary artery disease receiving low dose aspirin.METHODS
Aggregatory responses to the cannabinoids 2-AG and Δ9-THC were examined in blood sampled from healthy volunteers (n= 8) and patients (n= 12) with coronary artery disease receiving aspirin using whole blood aggregometry. The effects of CB1 (AM251) and CB2 (AM630) antagonists, as well as fatty acid amide hydrolase (FAAH) and monoacyl glycerol lipase (MAGL) inhibitors and aspirin on 2-AG-induced aggregation were also assessed.RESULTS
AM251 (100 nm–30 µm) had no effect on platelet aggregation induced by either ADP (P= 0.90) or thrombin (P= 0.86). 2-AG, but not Δ9-THC, induced aggregation. 2-AG-induced aggregation was unaffected by AM251 and AM630 but was abolished by aspirin (P < 0.001) and by the MAGL inhibitor, URB602 (P < 0.001). Moreover, the aggregatory response to 2-AG was depressed (by >75%, P < 0.001) in blood from patients with coronary artery disease receiving aspirin compared with that from healthy volunteers.CONCLUSIONS
2-AG-mediated activation of platelets is via metabolism to arachidonic acid by MAGL, and not through direct action on CB1 or CB2 receptors, at least in the acute phase. 相似文献8.
Marek Zadrozniak Marcin Szymanski Jarogniew J. Luszczki 《Pharmacological reports : PR》2019,71(2):351-356
Background
Drug-induced ototoxicity is still a main clinical problem in otolaryngology. It is widely known that aminoglycoside antibiotics combined with loop diuretics significantly contribute to permanent ototoxicity. The aim of this study was to find out whether ascorbic acid (vitamin C) is able to reverse or alleviate ototoxicity evoked by systemic (ip) administration of combination of amikacin and furosemide in experimental male albino Swiss mice.Methods
Ototoxic combination of amikacin and furosemide was isobolographically evaluated based on the hearing threshold decreasing doses by 20% and 50% (TDD20 and TDD50), respectively. Linear regression analysis was used to determine the TDD20 and TDD50 values for amikacin, furosemide, vitamin C administered alone and in combination (at the fixed-ratio of 1:1).Results
Vitamin C (in a dose of 500?mg/kg, ip) alleviated the impairment in hearing threshold evoked by combined ip administration of amikacin and furosemide (at the fixed-ratio of 1:1) in mice by reducing TDD50 values from 49.82 to 21.56 (p?<? 0.01). In contrast, vitamin C (500?mg/kg, ip) had no significant effect on TDD20 values for the combination of amikacin and furosemide at the fixed-ratio of 1:1.Conclusions
Vitamin C administered together with ototoxic drug combination of amikacin and furosemide reduced ototoxicity evoked by this two-drug combination in the experimental mice. 相似文献9.
Parham Jabbarzadeh Kaboli Melody Pui-Yee Leong Patimah Ismail King-Hwa Ling 《Pharmacological reports : PR》2019,71(1):13-23
Background
Berberine is an alkaloid plant-based DNA intercalator that affects gene regulation, particularly expression of oncogenic and tumor suppressor proteins. The effects of berberine on different signaling proteins remains to be elucidated. The present study aimed to identify the effects of berberine against key oncogenic proteins in breast cancer cells.Methods
Molecular docking and molecular dynamics simulations were used for EGFR, p38, ERK1/2, and AKT. The effects of berberine and lapatinib on MAPK and PI3K pathways in MDA-MB231 and MCF-7 cells were evaluated using immunoflorescence assays, and the amounts of phosphorylated kinases were compared to total kinases after treating with different concentrations of berberine.Results
Simulations showed berberine accurately interacted with EGFR, AKT, P38, and ERK1/2 active sites in silico (scores = -7.57 to -7.92 Kcal/mol) and decreased the levels of active forms of corresponding enzymes in both cell lines; however, berberine binding to p38 showed less stability. Cytotoxicity analysis indicated that MDA-MB231 cells were resistant to berberine compared to MCF-7 cells [72?h IC50?=?50 versus 15 μM, respectively). Also, lapatinib strongly activated AKT but suppressed EGFR in MDA-MB231 cells. The activity of EGFR, AKT, P38, and ERK1/2 were affected by berberine; however, berberine dramatically reduced EGFR and AKT phosphorylation.Conclusion
By way of its multikinase inhibitory effects, berberine might be a useful replacement for lapatinib, an EGFR inhibitor which can cause acquired drug resistance in patients. 相似文献10.
Beata Wilenska Dagmara Tymecka Marcin Włodarczyk Aleksandra Sobolewska-Włodarczyk Maria Wiśniewska-Jarosińska Jolanta Dyniewicz Árpád Somogyi Jakub Fichna Aleksandra Misicka 《Pharmacological reports : PR》2019,71(1):42-47
Background
Inflammatory bowel diseases (IBD) are a group of chronic and recurrent gastrointestinal disorders that are difficult to control. Recently, a new IBD therapy based on the targeting of the endogenous opioid system has been proposed. Consequently, due to the fact that endogenous enkephalins have an anti-inflammatory effect, we aimed at investigating the degradation of serum enkephalin (Met- and Leu-enkephalin) in patients with IBD.Methods
Enkephalin degradation in serum of patients with IBD was characterized using mass spectrometry methods. Calculated half-life (T1/2) of enkephalins were compared and correlated with the disease type and gender of the patients. Additionally, statistical analysis was used to examine the dynamics of changes in terms of inhibition of enkephalins degradation within research groups.Results
Our research indicates that the degree of enkephalins degradation depends on the gender of the patients. The difference is most evident for the rate of Met-enkephalin degradation between men (mean T1/2?=?13.61?min) and women (mean T1/2 ?=?21.84?min) with Crohn’s disease (CD).Conclusions
The most significant alternation of enkephalins degradation in serum samples of IBD patients, compared to control group, were observed in both Crohn’s disease and ulcerative colitis (UC) female patients. We suggest that the differences observed between the genders in IBD patients may be explained by regulation of enkephalinases activity by estradiol. 相似文献11.
12.
V Curto-Reyes S Llames A Hidalgo L Men��ndez A Baamonde 《British journal of pharmacology》2010,160(3):561-573
Background and purpose:
The activation of CB2 receptors induces analgesia in experimental models of chronic pain. The present experiments were designed to study whether the activation of peripheral or spinal CB2 receptors relieves thermal hyperalgesia and mechanical allodynia in two models of bone cancer pain.Experimental approach:
NCTC 2472 osteosarcoma or B16-F10 melanoma cells were intratibially inoculated to C3H/He and C57BL/6 mice. Thermal hyperalgesia was assessed by the unilateral hot plate test and mechanical allodynia by the von Frey test. AM1241 (CB2 receptor agonist), AM251 (CB1 receptor antagonist), SR144528 (CB2 receptor antagonist) and naloxone were used. CB2 receptor expression was measured by Western blot.Key results:
AM1241 (0.3–10 mg·kg−1) abolished thermal hyperalgesia and mechanical allodynia in both tumour models. The antihyperalgesic effect was antagonized by subcutaneous, intrathecal or peri-tumour administration of SR144528. In contrast, the antiallodynic effect was inhibited by systemic or intrathecal, but not peri-tumour, injection of SR144528. The effects of AM1241 were unchanged by AM251 but were prevented by naloxone. No change in CB2 receptor expression was found in spinal cord or dorsal root ganglia.Conclusions and implications:
Spinal CB2 receptors are involved in the antiallodynic effect induced by AM1241 in two neoplastic models while peripheral and spinal receptors participate in the antihyperalgesic effects. Both effects were mediated by endogenous opiates. The use of drugs that activate CB2 receptors could be a useful strategy to counteract bone cancer-induced pain symptoms. 相似文献13.
Rodopi Stamatiou Efrosini Paraskeva Anna Vasilaki Apostolia Hatziefthimiou 《Pharmacological reports : PR》2019,71(2):225-232
Background
Muscarinic receptor antagonists are a usual treatment for chronic airway diseases, with increased bronchoconstriction, like asthma and chronic obstructive pulmonary disease. These diseases are usually accompanied by airway remodeling, involving airway smooth muscle cell (ASMC) proliferation. The purpose of this study was to examine the effect of the muscarinic receptor modulator gallamine on rabbit tracheal ASMC proliferation.Methods
ASMCs were incubated with gallamine (1?nM–10?mM), atropine (1 fM–10?mM), and/or acetylcholine (1?nM–1?mM), in the presence or absence of FBS (1% or 10%). Cell proliferation was estimated by incorporation of radioactive thymidine, the Cell Titer AQueous One Solution method and cell number counting after Trypan blue exclusion. The mechanisms mediating cell proliferation were studied using the PI3K and MAPK inhibitors LY294002 (20?μM) and PD98059 (100?μM), respectively. Cell phenotype was studied by indirect immunofluorescence for α-actin, Myosin Heavy Chain and desmin.Results
ASMC incubation with the muscarinic receptor allosteric modulator gallamine or the muscarinic receptor antagonist atropine increased methyl-[3H]thymidine incorporation and cell number in a dose-dependent manner. ASMC proliferation was mediated via PI3K and MAPK activation and was transient. Gallamine antagonized the mitogenic effect of 1% FBS. Furthermore, gallamine had a similar effect on contractile ASMCs, without synergizing with or affecting acetylcholine induced proliferation, or altering the percentage of ASMCs expressing contractile phenotype marker proteins.Conclusions
Gallamine, in the absence of any agonist, has a transient mitogenic effect on ASMCs, regardless of the cell phenotype, mediated by the PI3K and the MAPK signaling pathways. 相似文献14.
BACKGROUND AND PURPOSE
Rimonabant (SR141716) and the structurally related AM251 are widely used in pharmacological experiments as selective cannabinoid receptor CB1 antagonists / inverse agonists. Concentrations of 0.5–10 µM are usually applied in in vitro experiments. We intended to show that these drugs did not act at GABAA receptors but found a significant positive allosteric modulation instead.EXPERIMENTAL APPROACH
Recombinant GABAA receptors were expressed in Xenopus oocytes. Receptors were exposed to AM251 or rimonabant in the absence and presence of GABA. Standard electrophysiological techniques were used to monitor the elicited ionic currents.KEY RESULTS
AM251 dose-dependently potentiated responses to 0.5 µM GABA at the recombinant α1β2γ2 GABAA receptor with an EC50 below 1 µM and a maximal potentiation of about eightfold. The Hill coefficient indicated that more than one binding site for AM251 was located in this receptor. Rimonabant had a lower affinity, but a fourfold higher efficacy. AM251 potentiated also currents mediated by α1β2, αxβ2γ2 (x = 2,3,5,6), α1β3γ2 and α4β2δ GABAA receptors, but not those mediated by α1β1γ2. Interestingly, the CB1 receptor antagonists LY320135 and O-2050 did not significantly affect α1β2γ2 GABAA receptor-mediated currents at concentrations of 1 µM.CONCLUSIONS AND IMPLICATIONS
This study identified rimonabant and AM251 as positive allosteric modulators of GABAA receptors. Thus, potential GABAergic effects of commonly used concentrations of these compounds should be considered in in vitro experiments, especially at extrasynaptic sites where GABA concentrations are low.LINKED ARTICLES
This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue-8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue-7 相似文献15.
Roman Sergeevich Tumskiy Gennady Leonidovich Burygin Alexander Andreevich Anis’kov Iraida Nikolaevna Klochkova 《Pharmacological reports : PR》2019,71(2):357-360
Background
A variety of spirooxindoles have demonstrated cytotoxic activity toward several cancer cell lines. This study investigates the cytotoxicity of five novel spirooxindole-pyrrolidines by using the Vero and HeLa cell lines.Methods
Vero and HeLa cells were treated with the synthesized spirooxindoles, and the cytotoxicity was evaluated by using the AlamarBlue Cell Viability Reagent and live/dead assay.Results
A series of poly-substituted pyrrolidines differing in nature and in substituent positions were obtained, with yields of 42–63%. Of the synthesized cycloadducts, 3-picolinoyl-4-(2,4-dichlorophenyl)-5-phenylspiro[indoline-3,2'-pyrrolidine]-2'-one (4) was the most cytotoxic (IC50 < 20?μg/ml for both cell lines). Besides, 3-picolinoyl-4-(2-chlorophenyl)-5-phenylspiro[indoline-3,2'-pyrrolidine]-2'-one (1) was three times more toxic to the HeLa cancer cell line (IC50?=?70?μg/ml) than it was to the Vero healthy cell line. The cytotoxicity of compounds 1 and 4 was confirmed with a live/dead assay. The cytotoxicity of a molecule was found to depend on the substitution nature on the benzene ring at the C-4 atom.Conclusion
3-Picolinoyl-4-(2-chlorophenyl)-5-phenylspiro[indoline-3,2'-pyrrolidine]-2'-one (1) can be used as a source for the synthesis of novel therapeutic agents against cancer. 相似文献16.
Cluny NL Vemuri VK Chambers AP Limebeer CL Bedard H Wood JT Lutz B Zimmer A Parker LA Makriyannis A Sharkey KA 《British journal of pharmacology》2010,161(3):629-642
BACKGROUND AND PURPOSE
Cannabinoid CB1 receptor antagonists reduce food intake and body weight, but clinical use in humans is limited by effects on the CNS. We have evaluated a novel cannabinoid antagonist (AM6545) designed to have limited CNS penetration, to see if it would inhibit food intake in rodents, without aversive effects.EXPERIMENTAL APPROACH
Cannabinoid receptor binding studies, cAMP assays, brain penetration studies and gastrointestinal motility studies were carried out to assess the activity profile of AM6545. The potential for AM6545 to induce malaise in rats and the actions of AM6545 on food intake and body weight were also investigated.KEY RESULTS
AM6545 binds to CB1 receptors with a Ki of 1.7 nM and CB2 receptors with a Ki of 523 nM. AM6545 is a neutral antagonist, having no effect on cAMP levels in transfected cells and was less centrally penetrant than AM4113, a comparable CB1 receptor antagonist. AM6545 reversed the effects of WIN55212-2 in an assay of colonic motility. In contrast to AM251, AM6545 did not produce conditioned gaping or conditioned taste avoidance in rats. In rats and mice, AM6545 dose-dependently reduced food intake and induced a sustained reduction in body weight. The effect on food intake was maintained in rats with a complete subdiaphragmatic vagotomy. AM6545 inhibited food intake in CB1 receptor gene-deficient mice, but not in CB1/CB2 receptor double knockout mice.CONCLUSIONS AND IMPLICATIONS
Peripherally active, cannabinoid receptor antagonists with limited brain penetration may be useful agents for the treatment of obesity and its complications. 相似文献17.
Duygun Altıntaş Aykan Tuba Tulay Koca Selma Yaman Nadire Eser 《Pharmacological reports : PR》2019,71(2):306-310
Background
We hypothesized that renin-angiotensin system and neprilysin (NEP) inhibition can modulate the nociceptive parameters on hypertensive rats. The aim of this study is to assess the preventive and therapeutic effects of ramipril and sacubitril on the pain hypersensitivities, and their interaction mechanisms with high blood pressure.Methods
Antinociceptive effects of ramipril and sacubitril were compared with those of diclofenac. Threshold of pain assesments were recorded before drugs administration. After a 18 days treatment, normotensive and dexamethasone-induced hypertensive rats were evaluated on thermal hyperalgesia and mechanical allodynia tests. Blood pressure of rats were verified by mean arterial pressure measurement.Results
Hypertensive rats showed significantly high pain threshold on thermal plantar test compared to that of normotensives. Among hypertensive rats, pain hypersensitivity was lowest in diclofenac group, followed by sacubitril group, while ramipril caused increased thermal and mechanical hypersensitivities.Conclusion
We found that NEP inhibition may play a role in nociception in hypertensive rats. NEP inhibitors may be suitable choice for the management of hypertension and pain because of their therapeutic and preventive effects on nociception and arterial blood pressure. 相似文献18.
Fatemeh Delrobaei Iman Fatemi Ali Shamsizadeh Mohammad Allahtavakoli 《Pharmacological reports : PR》2019,71(1):133-138
Background
Menopause is associated with increased oxidative stress and memory impairment. Based on the antioxidant property of ascorbic acid (AA), It’s effect on cognitive function, the serum level of the brain-derived neurotrophic factor (BDNF) and the activity of antioxidant enzymes within the brain in ovariectomized (OVX) mice was investigated.Methods
AA (100, 300 and 500?mg/kg), was orally administrated per day in OVX mice for 30 days. Tactile learning and working memory were evaluated by the novel object recognition task and T-maze continuous alternation task, respectively. The levels of serum BDNF were measured and animals’ brains were analyzed for the superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity.Results
AA prevented from the deleterious effects of ovariectomy on learning memory (300 and 500?mg/kg) and working memory (100 and 500?mg/kg). The serum BDNF level was also increased in OVX animals treated with AA (100 and 500?mg/kg). Furthermore, AA (500?mg/kg) increased the SOD and GPx activity in the brain of OVX animals.Conclusions
Collectively, the results of the present study suggest that AA might be an appropriate choice in loss or reduction of estradiol for the amelioration of cognitive impairment. 相似文献19.
Yong Su Qingqing Chen Keke Ma Yinghui Ju Tianjiao Ji Zhongyuan Wang Weizu Li Weiping Li 《Pharmacological reports : PR》2019,71(2):319-329
Background
The increased in?ux of free fatty acids (FFAs) into the kidney is a risk factor for diabetes nephropathy (DN). In the present study we investigated the effects of astragaloside IV (AS-IV) on FFA-induced lipid accumulation, oxidative stress, and activation of TGF-β1 signaling in human glomerular mesangial cells (HMCs).Methods
A DN model was induced in Sprague Dawley rats by the administration of a high-fat diet and streptozocin, and HMCs were stimulated with palmitate. Lipid accumulation and FFA uptake were detected using Oil Red O and BODIPY? FL C16 staining, respectively. The expression levels of TGF-β1, p-Smad2/3, FN, Col4?A1, NOX4, p22phox, and CD36 were evaluated by western blotting or immunofluorescence/immunohistochemistry. The level of reactive oxygen species (ROS) was detected using 2′,7′-dichlorofluorescein diacetate and dihydroethidium.Results
Exposure to palmitate induced marked lipid accumulation in HMCs, whereas co-treatment with AS-IV significantly attenuated this phenomenon. Moreover, AS-IV suppressed palmitate-induced expression of TGF-β1, p-Smad2/3, FN, Col4?A1, NOX4, and p22phox, in addition to ROS production. Notably, AS-IV reduced the palmitate-induced expression of CD36 in HMCs and DN rats. Treatment of HMCs with the CD36 inhibitor, sulfo-N-succinimidyl oleate (SSO), significantly attenuated FFA uptake, oxidative stress, and fibrosis. Nevertheless, the combined use of SSO and AS-IV did not enhance the efficacy.Conclusion
AS-IV inhibited palmitate-induced HMCs oxidative stress and fibrosis via the downregulation of CD36 expression, mediating FFA uptake and lipid accumulation. 相似文献20.
Wojciech Garczorz Enrique Gallego-Colon Agnieszka Kosowska Krzysztof Siemianowicz Agnieszka Kłych-Ratuszny Michał Woźniak Mohammad Reza F. Aghdam Tomasz Francuz Mariola Dorecka 《Pharmacological reports : PR》2019,71(1):175-182
