Abstract:
:1. We set out to elucidate the pharmacological mechanisms by which alpha 2-adrenoceptor and 5-HT-receptor ligands affect the haemodynamic response to acute central hypovolaemia in conscious rabbits. 2. Acute central hypovolaemia was produced by inflating an inferior vena caval cuff so that cardiac output fell at a constant rate of approximately 8.5% of its baseline level per min. 3. Drugs were administered into the fourth cerebral ventricle in either 154 mM NaCl (saline) or 20% w/v 2-hydroxypropyl-beta-cyclodextrin (beta-CDX). After vehicle treatments, the haemodynamic response to acute central hypovolaemia had the usual two phases. During Phase I, systemic vascular conductance fell in proportion to cardiac output so that mean arterial pressure fell by only 8 mmHg. Phase II commenced when cardiac output had fallen to approximately 60% of its baseline level, when vascular conductance rose abruptly and arterial pressure fell to < or = 40 mmHg. The haemodynamic response was not dependent on the vehicle used (saline or beta-CDX). 4. Methysergide delayed the occurrence of Phase II in a dose-dependent manner, and prevented it at a dose of 30- 600 nmol (geometric mean = 186 nmol). The effects and potency of methysergide were not dependent on the vehicle used, indicating that beta-CDX can be used as a vehicle for fourth ventricular administration of lipophilic drugs to conscious rabbits. Clonidine (10 nmol) reversed the effects of a critical dose of methysergide. 5. Phase II was also prevented by 8-hydroxy-2-(di-n-propylamino)tetralin (5-HT1A-selective agonist, geometric mean critical dose (range) = 13.1 (10-30) nmol), sumatriptan (5-HT1D-selective agonist, 72.1 (10-300) nmol), mesulergine (5-HT2/1C-selective antagonist, 173 (30-1000) nmol), idazoxan (alpha 2-adrenoceptor-selective antagonist, 548 (100-3000) nmol), and mianserin (5-HT2/1C-selective antagonist, 548 (100-3000) nmol). It was not affected by MDL 72222 (5-HT3-selective antagonist, 300 nmol) or ketanserin (5-HT2/1C-selective antagonist, 3000 nmol). 6. To characterize the nature of alpha 2-adrenoceptors in rabbit brainstem, we examined the binding of [3H]-rauwolscine to membrane homogenates of whole brainstem. [3H]-rauwolscine bound to a population of sites with the characteristics of alpha 2A-adrenoceptors. 7. From these results we suggest that activation of 5-HT1A receptors in the brainstem can prevent Phase II of the response to acute central hypovolaemia in conscious rabbits. Our results do not support the notion of an endogenous 5-hydroxytryptaminergic mechanism mediating Phase II. The mechanism by which the alpha 2-adrenoceptor antagonists yohimbine and idazoxan prevent Phase II remains to be elucidated. However, their potency relative to other 5-HT-receptor ligands indicates that an agonist action at 5-HT1A-receptors is more likely than an antagonist action at alpha 2-adrenoceptors.
journal_name
Br J Pharmacoljournal_title
British journal of pharmacologyauthors
Evans RG,Haynes JM,Ludbrook Jdoi
10.1111/j.1476-5381.1993.tb13528.xsubject
Has Abstractpub_date
1993-05-01 00:00:00pages
37-47issue
1eissn
0007-1188issn
1476-5381journal_volume
109pub_type
杂志文章abstract::1. In the anaesthetized dog bombesin had a potent antidiuretic effect, and sometimes arrested urine flow completely. Threshold doses, by i.v. infusion, were of the order of 0.5-1 (ng/kg)/minute. Antidiuresis was the result of a reduction in glomerular filtration rate provoked by a fall in intraglomerular hydrostatic p...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1973.tb08352.x
更新日期:1973-07-01 00:00:00
abstract::Despite progression in anticancer drug development and improvements in the clinical utilization of therapies, current treatment regimes are still dependent upon the use of systemic antiproliferative cytotoxic agents. Although these agents are unquestionably potent, their efficacy is limited by toxicity towards 'normal...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1038/sj.bjp.0707657
更新日期:2008-04-01 00:00:00
abstract::Forty-eight isolated rat hearts were perfused with Krebs solution and with [(3)H]-(-)-noradrenaline ([(3)H]-NA) containing 4.5 nCi/ml in 50 ng/ml, as described by Iversen (1963). To groups of six, cocaine was added to [(3)H]-NA in concentrations of 400 nM, 2 and 10 muM. To the rest Tween 80, 25 mug/ml was added to [(3...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1974.tb10686.x
更新日期:1974-07-01 00:00:00
abstract::1. The effects of intradermally injected prostaglandins (PGs) E(1), E(2), F(1alpha) and F(2alpha) have been examined in the rat and in man.2. PGE(1) and PGE(2) caused an increase in local vascular permeability in rat skin; their potency was comparable with that of other putative mediators of inflammation (histamine, b...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1971.tb09934.x
更新日期:1971-01-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Fatty acid amide hydrolase (FAAH) inhibitors are postulated to possess anti-hypertensive potential, because their acute injection decreases BP in spontaneously hypertensive rats (SHR), partly through normalization of cardiac contractile function. Here, we examined whether the potential hypotensiv...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.13830
更新日期:2017-07-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Inflammation associated with the tumour microenvironment (TME) plays a critical role in the cancer development, and immunotherapeutic strategies that aim to modulate the immune response in cancer have been crucial. In this study, a Methotrexate-loaded (MTX) poly (lactic-co-glycolic acid)-based (P...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.15373
更新日期:2021-01-12 00:00:00
abstract::1. An 'atypical' 5-HT2 receptor which is located on the endothelium of rat jugular vein has been described. In the present study we have further defined the nature of the 5-HT2 receptor subtype present in this preparation. 2. In experiments conducted in the presence of ketanserin to preclude involvement of 5-HT2 recep...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1995.tb13240.x
更新日期:1995-01-01 00:00:00
abstract::1. Column chromatography with Agarose A50m followed by Sephadex G100 was used to separate a fraction (extract II) in the molecular weight range 12,000 to 14,000 daltons from saline extracts of the sea anemone, Tealia felina. 2. Extract II inhibited histamine-induced contractions of the guinea-pig ileum and produced ha...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1981.tb09115.x
更新日期:1981-02-01 00:00:00
abstract::1. The novel bradykinin antagonist, HOE 140, completely blocked the fall in rabbit blood pressure caused, not only by i.v. bradykinin, but also by i.v. kallikrein. This shows that both the effects of exogenously administered bradykinin and those of endogenously released kinins are antagonized by HOE 140. 2. Acute panc...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb12751.x
更新日期:1992-10-01 00:00:00
abstract::1. Besides its antimuscarinic effects, propiverine may possess an additional mode of action. We compared the effects of propiverine, three of its metabolites (M-5, M-6, M-14) and atropine in human, pig and mouse urinary bladder preparations in order to elucidate the nature of a possible additional mode of action. 2. L...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0706244
更新日期:2005-07-01 00:00:00
abstract:BACKGROUND AND PURPOSE:(R,S)-ketamine produces rapid and significant antidepressant effects in approximately 65% of patients suffering from treatment-resistant bipolar depression (BD). The genetic, pharmacological and biochemical differences between ketamine responders and non-responders have not been identified. The p...
journal_title:British journal of pharmacology
pub_type: 杂志文章,随机对照试验
doi:10.1111/bph.12494
更新日期:2014-04-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Histone deacetylase 6 (HDAC6) and silent information regulator 2 (SIRT2) control the dynamics of the microtubule network via their deacetylase activities. Tubulin polymerization promoting protein (TPPP/p25) enhances microtubule acetylation by its direct binding to HDAC6. Our objective was to char...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.12946
更新日期:2015-02-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The two longest C-termini of the purinergic P2X receptors occur in the P2X2 and P2X7 receptors and are thought to interact with multiple cytoplasmic proteins, among which are members of the cytoskeleton, including microtubules. In this work we asked whether disrupting the microtubule cytoskeleton...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2011.01254.x
更新日期:2011-07-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The thiourea derivative KB-R7943, originally developed as inhibitor of the plasma membrane Na(+)/Ca(2+) exchanger, has been shown to protect against myocardial ischemia-reperfusion injury. We have studied here its effects on mitochondrial Ca(2+) fluxes. EXPERIMENTAL APPROACH:[Ca(2+)] in cytosol,...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0707260
更新日期:2007-07-01 00:00:00
abstract::1. The present study was designed to investigate tolerance to several pharmacological effects of apomorphine. 2. Changes in blood pressure, heart rate, plasma noradrenaline levels, rectal temperature, respiratory rate and retching plus vomiting were compared after administration of apomorphine (200 micrograms kg-1, i....
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1996.tb15260.x
更新日期:1996-03-01 00:00:00
abstract::1. OPC-31260, a benzazepine derivative, has been studied for its ability to antagonize the binding of arginine vasopressin (AVP) to receptors in rat liver (V1) and kidney (V2) plasma membranes, for antagonism of the antidiuretic action of AVP in alcohol-anaesthetized rats and for diuretic action in conscious normal ra...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb09058.x
更新日期:1992-04-01 00:00:00
abstract::1 The influence of dopamine receptor agonists on gastric acid secretion stimulated by thyrotropin-releasing hormone (TRH) was studied in the perfused stomach of anaesthetized rats. 2 Intraventricular TRH produced a dose-dependent stimulation of basal gastric acid secretion. 3 Pretreatment with apomorphine, bromocripti...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1983.tb10524.x
更新日期:1983-05-01 00:00:00
abstract::Δ9 -tetrahydrocannabinol, the principal active component in Cannabis sativa extracts such as marijuana, participates in cell signalling by binding to cannabinoid CB1 and CB2 receptors on the cell surface. The CB1 receptors are present in both inhibitory and excitatory presynaptic terminals and the CB2 receptors are fo...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1111/bph.14780
更新日期:2019-09-01 00:00:00
abstract::1. The effects of the spasmogenic agents, carbachol (CCh), histamine, 5-hydroxytryptamine (5-HT) and 9,11-epithio-11,12-methano-thromboxane A2 (STA2) were investigated on smooth muscle tissues of the dog trachea. 2. CCh (10 microM) produced a larger contraction than high K (128 mM), 10 microM histamine, 5-HT or STA2. ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1990.tb12049.x
更新日期:1990-05-01 00:00:00
abstract:BACKGROUND AND PURPOSE:We previously reported that NCX 2057, a compound comprising a nitric oxide (NO)-releasing moiety and the natural antioxidant, ferulic acid (FA), inhibits pro-inflammatory mediators through NO-mediated gene regulation. Here, we have assessed the activities of NCX 2057 in models of inflammatory and...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2009.00324.x
更新日期:2009-09-01 00:00:00
abstract:BACKGROUND AND PURPOSE:ARL 67156, 6-N,N-Diethyl-D-beta-gamma-dibromomethylene adenosine triphosphate, originally named FPL 67156, is the only commercially available inhibitor of ecto-ATPases. Since the first report on this molecule, various ectonucleotidases responsible for the hydrolysis of ATP at the cell surface hav...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0707361
更新日期:2007-09-01 00:00:00
abstract::Glucagon-like peptide 1 (GLP-1) is a relatively recently discovered molecule originating in the so-called L-cells of the intestine. The peptide has insulinotrophic properties and it is this characteristic that has predominantly been investigated. This has led to the use of the GLP-1-like peptide exendin-4 (EX-4), whic...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1111/j.1476-5381.2009.00486.x
更新日期:2010-02-01 00:00:00
abstract::1 The tension developed in the guinea-pig cremaster was recorded during spontaneous activity and electrical stimulation. Spontaneous rhythmic contraction was observed in many preparations, particularly in the tip of the cremaster. These contractions were very slow, lasting about 20 s and occuring at about 2 min interv...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1975.tb07423.x
更新日期:1975-12-01 00:00:00
abstract::1. Prostaglandin E2 (PGE2) is an autacoid that decreases proteoglycan synthesis, increases metalloprotease production by cultured chondrocytes, and can modulate some of the actions of interleukin-1 on cartilage. The objective of the present study was to characterize the subtype of prostaglandin E2 receptor present in ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1996.tb15580.x
更新日期:1996-08-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Peroxisome proliferator-activated receptors (PPARs) are ligand-activated transcription factors, and three subtypes (α, β and γ) have been identified. PPAR activation has been reported to decrease renal injury and markers of glomerular dysfunction in models of renal ischemia/reperfusion (I/R). How...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2010.01032.x
更新日期:2011-01-01 00:00:00
abstract::1 Endothelin-1 (ET-1), an endothelium-derived vasoactive peptide, participates in the regulation of endothelial function through mechanisms that are not fully elucidated. This study examined the impact of ET-1 on oxidative stress, apoptosis and cell proliferation in human umbilical vein endothelial cells (HUVEC). HUVE...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0706193
更新日期:2005-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:The locus coeruleus (LC) is a major source of noradrenergic projections to the dorsal spinal cord, and thereby plays an important role in the modulation of nociceptive information. The LC receives inputs from substance P (SP)-containing fibres from other regions, and expresses the NK(1) tachykin...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.2011.01820.x
更新日期:2012-06-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Haem oxygenase-1 (HO-1) is induced by thiazolidinediones including rosiglitazone and exerts anti-inflammatory effects in various models. However, the molecular mechanisms underlying rosiglitazone-induced HO-1 expression remain largely unknown in human pulmonary alveolar epithelial cells (HPAEpiCs...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/bph.14465
更新日期:2018-10-01 00:00:00
abstract::The effects of histamine and of H1- and H2-receptor agonists on the response to specific antigen were studied in isolated hearts taken from actively sensitized guinea-pigs. Histamine and H2-receptor agonists (dimaprit, impromidine) dose-dependently decrease the positive chronotropic and inotropic effects, and the seve...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1987.tb11195.x
更新日期:1987-03-01 00:00:00
abstract::Endothelin-1 (ET-1) is a peptide hormone produced within the myocardium which may modulate myocardial contractility in a paracrine-autocrine fashion. In the majority of species, ET-1 has a direct positive inotropic effect on the myocardium that involves both increased myofilament Ca(2+) sensitivity and increased Ca(2+...
journal_title:British journal of pharmacology
pub_type: 评论,杂志文章
doi:10.1038/sj.bjp.0707438
更新日期:2007-10-01 00:00:00