Abstract:
:1. The effectiveness of alpha 1- and alpha 2-adrenoceptor activation was compared at different levels of the saphenous and cephalic vein of the dog in vitro. 2. Helically cut strips were used to determine concentration-response curves to phenylephrine, noradrenaline, UK-14,304 (5-bromo-6-(imidazoline-2-ylamino)-quinoxaline) and B-HT 920 (2-amino-6-allyl-5,6,7,8-tetra-hydro-4H-(thiazo)-4,5-d-azepine). The effect of prazosin and yohimbine on these curves was also studied. 3. At the distal level, the maximum response to UK-14,304 amounted to 33 and 50% of those to noradrenaline in the saphenous and cephalic vein, respectively, while at the proximal level the maximum response to UK-14,304 amounted to 72 and 78% of those to noradrenaline, in the saphenous and cephalic vein, respectively. 4. In both vessels, the results obtained with B-HT 920 were very similar to those for UK-14,304. 5. The pD2 values for UK-14,304 - which were identical at the three levels of both vessels - and the pA2 values for the antagonism exerted by either prazosin or yohimbine against the responses to UK-14,304 indicate that the alpha 2-adrenoceptors are identical at the different levels of both vessels. 6. These results show that the effectiveness of alpha 2-adrenoceptor stimulation increases from the distal to the proximal regions of canine limb veins. Apparently, this is due to a greater density of alpha 2-adrenoceptors in the proximal regions. 7. Yohimbine is much more potent against phenylephrine distally than proximally in both vessels. However, after 30 nm phenoxybenzamine - a concentration which eliminates the vast majority of alpha,-adrenoceptors without affecting alpha 2-adrenoceptors - yohimbine became equally potent at both levels, suggesting that the difference existing before phenoxybenzamine depended on alpha,-adrenoceptors. Hence it is concluded that alpha,-adrenoceptors in distal and proximal portions may differ.
journal_name
Br J Pharmacoljournal_title
British journal of pharmacologyauthors
Guimaraes S,Nunes JPdoi
10.1111/j.1476-5381.1990.tb12719.xsubject
Has Abstractpub_date
1990-10-01 00:00:00pages
387-93issue
2eissn
0007-1188issn
1476-5381journal_volume
101pub_type
杂志文章abstract::1. The sulphonylureas, tolbutamide (0.1-10 mM) and glibenclamide (0.1-100 microM) shown not to inhibit ATP-K+ channel currents when applied to inside-out membrane patches excised from rat cultured cerebral cortex or freshly-dispersed ventromedial hypothalamic nucleus (VMHN) neurones. 2. Saturable binding sites for [3H...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1990.tb14116.x
更新日期:1990-11-01 00:00:00
abstract::1. Sabcomeline (SB-202026, 0.03 mg kg(-1), p.o.), a potent and functionally selective M1 receptor partial agonist, caused a statistically significant improvement in the performance of a visual object discrimination task by marmosets. No such improvement was seen after RS86 (0.1 mg kg(-1), p.o.). 2. Initial learning, w...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0701844
更新日期:1998-05-01 00:00:00
abstract::1. A murine macrophage cell line, J774, expressed nitric oxide (NO) synthase activity in response to interferon-gamma (IFN-gamma, 10 u ml-1) plus lipopolysaccharide (LPS, 10 ng ml-1). The enzyme activity was first detectable 6 h after incubation, peaked at 12 h and became undetectable after 48 h. 2. The decline in the...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1993.tb12886.x
更新日期:1993-03-01 00:00:00
abstract::1. Rasagiline [N-propargyl-1R(+)-aminoindan], was examined for its monoamine oxidase (MAO) A and B inhibitor activities in rats together with its S(-)-enantiomer (TVP 1022) and the racemic compound (AGN-1135) and compared to selegiline (1-deprenyl). The tissues that were studied for MAO inhibition were the brain, live...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0703826
更新日期:2001-01-01 00:00:00
abstract::1. We have investigated the potency and duration of action of isoprenaline and a range of beta-adrenoceptor agonists as relaxants of inherent tone in human superfused, isolated bronchial smooth muscle, a tissue reported to contain a homogeneous population of beta 2-adrenoceptors. 2. All of the beta-adrenoceptor agonis...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1993.tb13929.x
更新日期:1993-11-01 00:00:00
abstract::1. The effect of several metabotropic ligands and di- or tripeptides were tested on the binding of [3H]-L(+)-2-amino-4-phosphonobutyric acid ([3H]-L-AP4) on rat mGlu4 receptor. For selected compounds, the functional activity was determined on this receptor using the guanosine-5'[gamma-35S]-thiotriphosphate [gamma-35S]...
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更新日期:1999-11-01 00:00:00
abstract::1. The modulation of L-type calcium channel current (ICa) by fendiline, a diphenylalkylamine type of calcium channel blocker was investigated on guinea-pig ventricular myocytes by use of the whole-cell patch-clamp technique. 2. Fendiline-induced block of ICa is accompanied by modulation of the channel kinetics in a co...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb14308.x
更新日期:1992-05-01 00:00:00
abstract::1. The responses of bladder strips from control, streptozotocin-diabetic, and sucrose-drinking rats to electrical field stimulation were investigated. Sucrose-drinking rats were included as additional controls because they have enlarged bladders as a result of non-diabetic diuresis. 2. Bladder strips from diabetic rat...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1994.tb16193.x
更新日期:1994-09-01 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...
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abstract::1. The present study investigated the central effects of the selective serotonin reuptake inhibitor (SSRI) fluoxetine and the role of 5-hydroxytryptamine(3) (5-HT(3)) receptors in the core of the nucleus accumbens (NAc) on cocaine-induced behavioural changes in rats. 2. The 5-HT(3) receptor antagonist ondansetron (1 o...
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pub_type: 杂志文章
doi:10.1038/sj.bjp.0703687
更新日期:2000-12-01 00:00:00
abstract::1 Angiotensin I (AI) and AII elicited a dose-dependent potentiation of contractions by rat vas deferens produced by low frequency nerve stimulation without enhancing the contraction produced by exogenous noradrenaline. The AII-induced presynaptic potentiation was blocked by the specific antagonist cysteine(8)-AII.2 Th...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1974.tb09672.x
更新日期:1974-08-01 00:00:00
abstract::1. This study tested the hypothesis that the systemic effects of burn include altered metabolic activity in the heart. Metabolic activity was studied by measuring alterations in cyclic nucleotide levels and protein concentrations in atrial and ventricular muscle in mice at 14 and 22 days after a 20% body surface area ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1990.tb12698.x
更新日期:1990-10-01 00:00:00
abstract::1. In cultured endothelial cells of the pig the endothelium-derived relaxing factor (EDRF) releasing agent thrombin (2 u ml-1) caused a significant increase in basal levels of both guanosine 3':5'-cyclic monophosphate (cyclic GMP) and inositol 1,4,5-trisphosphate (IP3). This increase was time dependent, with peak leve...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1991.tb12166.x
更新日期:1991-01-01 00:00:00
abstract::1. Despite the observation of pharmacological responses to neuropeptide Y (NPY) in mammalian kidneys, there are species differences in the ease with which specific NPY binding sites can be demonstrated; we have investigated whether this can be explained by differential metabolism of NPY by a membrane-bound peptidase. ...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1991.tb12429.x
更新日期:1991-10-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0700908
更新日期:1997-02-01 00:00:00
abstract::The chemical trimethylcyclohexanol (TMC) is closely related to menthol, the major component of a terpene preparation with known choleretic and cholelitholytic activity. Its effects on hepatic cholesterol synthesis and bile secretion were examined in the rat. In both acute and long-term dosing experiments TMC significa...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1984.tb10759.x
更新日期:1984-01-01 00:00:00
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pub_type: 杂志文章
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journal_title:British journal of pharmacology
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doi:10.1111/j.1476-5381.1996.tb15198.x
更新日期:1996-01-01 00:00:00
abstract:BACKGROUND AND PURPOSE:Advanced glycation endproducts (AGE) have been implicated in the pathogenesis of diabetic complications, including diabetic cardiovascular dysfunctions. 3-benzyloxycarbonylmethyl-4-methyl-thiazol-3-ium bromide (C36), a novel AGE breaker, was investigated for its beneficial effects on the cardiova...
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更新日期:2007-12-01 00:00:00
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journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1989.tb12556.x
更新日期:1989-08-01 00:00:00
abstract::1 The beta-adrenoceptor agonist isoprenaline normally causes only a small and inconsistent increase in the membrane potential of cells in guinea-pig liver slices, in contrast to the large hyperpolarizations seen with alpha-agonists. However, after a selective alpha-adrenoceptor agonist has been applied, the response t...
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pub_type: 杂志文章
doi:10.1111/j.1476-5381.1977.tb06991.x
更新日期:1977-01-01 00:00:00
abstract::1. We investigated whether K(+) can act as an endothelium-derived hyperpolarizing factor (EDHF) in isolated small renal arteries of Wistar-Kyoto rats. 2. Acetylcholine (0.001 - 3 microM) caused relaxations that were abolished by removal of the endothelium. However, acetylcholine-induced relaxations were not affected b...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0703965
更新日期:2001-04-01 00:00:00
abstract::1. Repeated allergen challenge has been shown to increase the role of Rho-kinase in airway smooth muscle (ASM) contraction. We considered the possibility that active allergic sensitization by itself, that is, without subsequent allergen exposure, could be sufficient to enhance Rho-kinase-mediated ASM contraction. 2. G...
journal_title:British journal of pharmacology
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更新日期:2004-10-01 00:00:00
abstract::1. The action of angiotensin on the circular and longitudinal muscle of the human colon has been studied in vitro. The ED50 value (g/ml) of circular muscle was 8.7 x 10(-8) and of longitudinal muscle 3.1 x 10(-8), while the corresponding figures for acetylcholine were 1.6 x 10(-6) and 1.1 x 10(-6), respectively. Angio...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1970.tb09553.x
更新日期:1970-05-01 00:00:00
abstract::1. Recent studies demonstrated that inhibition or genetic inactivation of the enzyme poly (ADP-ribose) polymerase (PARP) is beneficial in myocardial reperfusion injury. PARP activation in the reperfused myocardium has been assumed, but not directly demonstrated. Furthermore, the issue whether pharmacological PARP inhi...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1038/sj.bjp.0704185
更新日期:2001-08-01 00:00:00
abstract::1. Short-circuit current (SCC) technique was used to study the adrenoceptors involved in the electrogenic chloride secretion by cultured cauda epididymal epithelium of rats. Stimulation of the epithelium with noradrenaline (primarily beta 1-adrenoceptor selective agonist), salbutamol (beta 2-adrenoceptor selective ago...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1992.tb14477.x
更新日期:1992-09-01 00:00:00
abstract::1. Endothelial cells, under given circumstances, can initiate contraction (constriction) of the vascular smooth muscle cells that surround them. Such endothelium-dependent, acute increases in contractile tone can be due to the withdrawal of the production of nitric oxide, to the production of vasoconstrictor peptides ...
journal_title:British journal of pharmacology
pub_type: 杂志文章,评审
doi:10.1038/sj.bjp.0706042
更新日期:2005-02-01 00:00:00
abstract::1. In decerebrated, non-spinalized rabbits, intrathecal administration of either of the selective 5-HT1A-receptor antagonists (S)WAY-100135 or WAY-100635 resulted in dose-dependent enhancement of the reflex responses of gastrocnemius motoneurones evoked by electrical stimulation of all myelinated afferents of the sura...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1996.tb16019.x
更新日期:1996-11-01 00:00:00
abstract::1. In the zymosan rat air pouch model of inflammation we have assessed the time dependence of phospholipase A2 (PLA2) accumulation in the inflammatory exudates as well as cell migration, myeloperoxidase activity, prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) levels. 2. A significant increase in PLA2 activity was d...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1996.tb15353.x
更新日期:1996-04-01 00:00:00
abstract::1. The role of vasoconstrictor 5-HT1-like receptors in the control of vascular reactivity in vivo has been relatively little studied, particularly with regards to venous function. Using an anaesthetized dog model, we have investigated the haemodynamic profile of the selective 5-HT1-like agonist, sumatriptan, focussing...
journal_title:British journal of pharmacology
pub_type: 杂志文章
doi:10.1111/j.1476-5381.1995.tb15055.x
更新日期:1995-10-01 00:00:00