Abstract:
:1. The modulation by alpha 2-adrenoceptors of the jaw-opening reflex (digastric electromyographic responses) elicited by orofacial electrical stimulation (OF-JOR) in pentobarbitone anaesthetized rats was investigated. 2. Increasing doses of clonidine (0.1-1000 micrograms kg-1, i.v.) reduced, in a dose-dependent manner until abolition, the amplitude and duration of the OF-JOR and increased the latency to onset. The sum of amplitudes of the reflex was the most sensitive parameter to the inhibitory effects of clonidine (ED50 = 13.9 micrograms kg-1). 3. Pretreatment with the alpha 2-adrenoceptor antagonist, idazoxan (0.03-1 mg kg-1, i.v.), caused a dose-dependent shift (1.5 to 37 fold) to the right of the dose-response curve for clonidine without significant change of maximum inhibitory effect, in a manner compatible with competitive antagonism (ED50B = 29.0 micrograms kg-1). Pretreatment with yohimbine (0.3 mg kg-1, i.v.) also antagonized the inhibitory effect of clonidine on the OF-JOR. In contrast, the alpha 2-adrenoceptor antagonist ARC-239 (0.3 mg kg-1, i.v.) did not antagonize the effect of clonidine on the reflex. 4. In rats pretreated with reserpine (5 mg kg-1, s.c., 18 h) the OF-JOR was not modified, but the potency of clonidine in inhibiting the reflex was potentiated (ED50 value decreased to 6.8 micrograms kg-1) without a significant change of maximum inhibitory effect. 5. Increasing doses of amphetamine (0.1-3000 micrograms kg-1, i.v.) caused a dose-related, but partial, inhibition of the OF-JOR (ED50 = 135 micrograms kg-1; Emax = 67%). Pretreatment with idazoxan (0.1 mg kg-1, i.v.)induced a nine fold shift to the right of the dose-response curve for amphetamine, while treatment with the depleting drug alpha-methyl-p-tyrosine (150mg kg-1 daily, i.p., for 14 days) abolished the inhibitory effect of this indirect adrenoceptor agonist on the OF-JOR.6. Morphine (0.1-3000 microgkg-1, i.v.) also reduced the OF-JOR in a dose-dependent manner (ED50 value about 325 microg kg-1) but, in contrast to clonidine, it failed to inhibit the reflex fully (Emax = 48%).As expected, pretreatment with the opioid antagonist naloxone (1 mg kg-1, i.v.) abolished the inhibitory effect of morphine on the OF-JOR, while it did not alter that of clonidine.7. Chronic, but not acute, pretreatment with idazoxan (3 mg kg-1 daily, i.p. for 14 days) led to a marked potentiation of the inhibitory effect of clonidine on the OF-JOR (ED50 value decreased to 4.2 microg kg-1), without a significant change of maximum inhibitory effect.8. Together the results indicate that clonidine evokes a potent inhibition of the OF-JOR in rats through the activation of postsynaptic alpha2-adrenoceptors. It is suggested that this functional response represents a simple and useful in vivo model for studying various regulatory mechanisms of central alpha2-adrenoceptors.
journal_name
Br J Pharmacoljournal_title
British journal of pharmacologyauthors
García-Vallejo P,Barturen F,García-Sevilla JAdoi
10.1111/j.1476-5381.1994.tb14864.xsubject
Has Abstractpub_date
1994-04-01 00:00:00pages
1140-6issue
4eissn
0007-1188issn
1476-5381journal_volume
111pub_type
杂志文章abstract:BACKGROUND AND PURPOSE:Pyrazole derivatives have recently been suggested as selective blockers of transient receptor potential cation (TRPC) channels but their ability to distinguish between the TRPC and Orai pore complexes is ill-defined. This study was designed to characterize a series of pyrazole derivatives in term...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2012.02126.x
更新日期:2012-12-01 00:00:00
abstract::1. Juvenile male rats treated with parachlorophenylalanine showed hair loss round the head and neck extending down the chest and abdomen.2. Treated isolated rats did not have this loss of hair, while untreated animals living in the same cage as treated rats lost their hair. The loss therefore seems to be caused by inc...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1970.tb08518.x
更新日期:1970-02-01 00:00:00
abstract::Perivascular adipose tissue (PVAT) is now recognized as an active player in vascular homeostasis. The expansion of PVAT in obesity and its possible role in vascular dysfunction have attracted much interest. In terms of the regulation of vascular tone and blood pressure, PVAT has been shown to release vasoactive mediat...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1111/bph.13767
更新日期:2017-10-01 00:00:00
abstract::1. The effects of intravenous administration of two alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) antagonists were studied on responses of single neurones to iontophoretically applied excitatory amino acids. The tests were performed on spinal neurones in alpha-chloralose anaesthetized, spinalized rat...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1994.tb13156.x
更新日期:1994-07-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Orexins have been demonstrated to play important roles in many physiological processes. However, it is not known how orexin A affects the activity of the hypoglossal motoneuron (HMN) and genioglossus (GG) muscle. EXPERIMENTAL APPROACH:GG muscle electromyograms (GG-EMG) were recorded in anaesthet...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.12784
更新日期:2014-09-01 00:00:00
abstract::1. Several amino-acid esters and amides have been prepared and their toxicological and pharmacological properties have been investigated. Some of the quaternary esters and amides were lethal to mice at doses below 1 mg/kg; this lethality was usually associated with high nicotinic activity. None of the compounds showed...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1968.tb07056.x
更新日期:1968-10-01 00:00:00
abstract::1. Des-Arg9 bradykinin (DAB), a classical B1-kinin receptor agonist was without effect when applied to the basolateral surface of rat isolated colon epithelium. Three hours after tissues were isolated DAB caused, after a delay of up to 2 min, a maintained increase of short circuit current (SCC). 2. The SCC increase in...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0701225
更新日期:1997-07-01 00:00:00
abstract::1. The kinetics of glycine-sensitive, N-methyl-D-aspartate (NMDA) receptor desensitization were investigated in cultured neurones with the patch clamp technique. 2. The degree of fast NMDA-receptor desensitization was inversely related to glycine concentration. Thus, increasing concentrations of glycine from 30 nM to ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1993.tb13556.x
更新日期:1993-05-01 00:00:00
abstract::Mitochondrial permeability transition pore (mPTP) opening plays a critical role in cardiac reperfusion injury and its prevention is cardioprotective. Tumour cell mitochondria usually have high levels of hexokinase isoform 2 (HK2) bound to their outer mitochondrial membranes (OMM) and HK2 binding to heart mitochondria ...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1111/bph.12899
更新日期:2015-04-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Cytochrome P450 (CYP, P450) 3A4 is involved in the metabolism of 50% of drugs and its catalytic activity in vivo is not explained only by hepatic expression levels. We previously demonstrated that UDP-glucuronosyltransferase (UGT) 2B7 suppressed CYP3A4 activity through an interaction. In the pres...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.14900
更新日期:2020-03-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The rat respiratory muscle diaphragm has markedly lower sensitivity than the locomotor muscle extensor digitorum longus (EDL) to the new acetylcholinesterase (AChE) inhibitors, alkylammonium derivatives of 6-methyluracil (ADEMS). This study evaluated several possible reasons for differing sensiti...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2011.01211.x
更新日期:2011-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Although botulinum toxin type A (BoNT/A) is approved for chronic migraine treatment, its mechanism of action is still unknown. Dural neurogenic inflammation (DNI) commonly used to investigate migraine pathophysiology can be evoked by trigeminal pain. Here, we investigated the reactivity of crania...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.13366
更新日期:2016-01-01 00:00:00
abstract::1. This study analyses the receptors mediating the effects of bradykinin (BK) and analogues on neurogenic twitch contractions of the mouse isolated vas deferens evoked, in the presence of captopril (3 microM), by electrical field stimulation with trains of 4 rectangular 0.5 ms pulses of supramaximal strength, delivere...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1995.tb13372.x
更新日期:1995-04-01 00:00:00
abstract::1. Histamine stimulated the accumulation of total [3H]-inositol phosphates (IPn) in control HeLa cells with an EC50 of 3.7 +/- 0.7 microM in the presence of 10 mM LiCl. The maximum response to histamine after 15 min incubation was 43 +/- 5% over basal accumulation and occurred at a concentration of 1 mM histamine. 2. ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1993.tb13577.x
更新日期:1993-06-01 00:00:00
abstract::1. The pharmacological features of rat white adipocyte beta-adrenoceptor subtypes were investigated by saturation and beta-agonist competition studies with [3H]-CGP 12177 and by lipolysis induced by beta-agonists as well as their inhibition by CGP 20712A (selective beta 1-antagonist) and ICI 118551 (selective beta 2-a...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0700885
更新日期:1997-01-01 00:00:00
abstract::1. Sodium metabisulphite (MBS) can induce bronchoconstriction in patients with asthma. We investigated the effects of MBS aerosol on bronchial blood velocity (Vbr) and pulmonary resistance in intubated conscious sheep. 2. Bronchial blood velocity was measured by implanting a 20 MHz ultrasonic Doppler flow probe on the...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1994.tb14826.x
更新日期:1994-03-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Cannabis extracts and several cannabinoids have been shown to exert broad anti-inflammatory activities in experimental models of inflammatory CNS degenerative diseases. Clinical use of many cannabinoids is limited by their psychotropic effects. However, phytocannabinoids like cannabidiol (CBD), d...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2011.01379.x
更新日期:2011-08-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Airway hyperresponsiveness (AHR) is a central abnormality in asthma. IL-5 may modulate AHR in animal models of asthma, but the available data is inconsistent on the impact of targeting IL-5 pathway against AHR. The difference between targeting IL-5 or the IL-5 receptor, α subunit (IL-5Rα) in modu...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.15240
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abstract::1. Under normal experimental conditions, the rabbit isolated distal saphenous artery appears to contain a homogeneous population of postjunctional alpha 1-adrenoceptors. Prazosin competitively antagonized responses to noradrenaline (NA) with a pA2 value of 8.6, while a relatively high concentration of rauwolscine (1 m...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1991.tb09815.x
更新日期:1991-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Cholecystokinin (CCK) is secreted by intestinal I cells and regulates important metabolic functions. In pancreatic islets, CCK controls beta cell functions primarily through CCK1 receptors, but the signalling pathways downstream of these receptors in pancreatic beta cells are not well defined. E...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.13271
更新日期:2015-11-01 00:00:00
abstract::1 PD 117302, a new nonpeptide opioid compound shown in in vitro studies to be a selective kappa-opioid agonist, has been evaluated in vivo for antinociceptive activity and other effects characteristic of kappa-receptor activation. 2 Dose-related long lasting antinociception was produced by PD 117302 against a mechanic...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1987.tb11398.x
更新日期:1987-12-01 00:00:00
abstract::1. In vivo microdialysis in halothane-anaesthetized rats and synaptosomal [3H]-noradrenaline uptake studies in vitro were used to evaluate the effects of imidazole (medetomidine) and imidazoline (clonidine and UK 14,304) alpha 2-adrenoceptor agonists on extraneuronal levels of noradrenaline in the frontal cortex. 2. L...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1995.tb14962.x
更新日期:1995-04-01 00:00:00
abstract::1. The effects of low oxygen tension on tone and on the responsiveness to contractile and relaxant agents were examined on circumflex coronary artery rings isolated from sheep. 2. When artery rings (2-2.5 mm o.d.) were set at their optimal resting tension, introduction of hypoxia (0% O2) caused a sustained contraction...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1989.tb11894.x
更新日期:1989-04-01 00:00:00
abstract::1. The endothelium-dependent relaxants acetylcholine (ACh; 0.03-10 microM) and A23187 (0.03-10 microM), and nitric oxide (NO), applied either as authentic NO (0.01-10 microM) or as the NO donors 3-morpholino-sydnonimine (SIN-1; 0.1-10 microM) and S-nitroso-N-acetylpenicillamine (SNAP; 0.1-10 microM), each evoked conce...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0701746
更新日期:1998-04-01 00:00:00
abstract::1. To clarify the role of the first thrombin receptor/protease-activated receptor (PAR)-1 in an inflammatory process, we tested and characterized the effect of intraplantar (i.pl.) administration of the highly specific PAR-1 agonist TFLLR-NH2 in rat hindpaw. 2. TFLLR-NH2 administered i.pl. at 0.01-0.03 micromol per pa...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0702513
更新日期:1999-04-01 00:00:00
abstract::1. In the presence of indomethacin (IM, 10 microM) and N omega-nitro-L- arginine (L-NOARG, 0.3 mM), acetylcholine (ACh) induces an endothelium-dependent smooth muscle hyperpolarization and relaxation in the rat isolated hepatic artery. The potassium (K) channel inhibitors, tetrabutylammonium (TBA, 1 mM) and to a lesse...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1996.tb15327.x
更新日期:1996-04-01 00:00:00
abstract::1 The specific stimulating action of dopamine and L-DOPA on exocrine pancreatic secretion was further investigated in the isolated blood-perfused canine pancreas.2 6-Hydroxydopamine (100 mug, i.a.) stimulated the secretion but was far less potent than dopamine. Epinine (0.3-1 mg. i.a.), alpha-methyldopamine (10-300 mu...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1974.tb09651.x
更新日期:1974-06-01 00:00:00
abstract::1. Possible interactions between non-steroidal anti-inflammatory drugs (NSAIDs) and endogenous opioids were examined in electrophysiological experiments in alpha-chloralose anaesthetized spinalized rats without or with carrageenan-induced acute inflammation of one hindpaw. Spinal reflex responses, monitored as single ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1996.tb15494.x
更新日期:1996-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Inhibition of PDE5 improves synaptic plasticity and memory via enhancing cGMP expression, thus activating the cGMP/cAMP response element binding protein (CREB) signalling pathway. This study investigated the effects of a PDE5 inhibitor on scopolamine-induced cognitive dysfunction, using memory-re...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.14377
更新日期:2018-08-01 00:00:00
abstract::We have performed a systematic mutagenesis of three hydrophobic rings (17', 13' and 9') within transmembrane region (TM) 2 of the alpha9alpha10 nicotinic cholinergic receptor (nAChR) to a hydrophilic (threonine) residue and compared the properties of mutant receptors reconstituted in Xenopus laevis oocytes. Phenotypic...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0706224
更新日期:2005-08-01 00:00:00