artemisia species, growing in almost all the northern hemisphere, is used in folk medicine of some countries as a remedy for hypertension. since some cardiovascular disorders including hypertension are accompanied with altered responsiveness of vascular alpha-adrenergic receptors, the effect of aqueous artemisia annua extract (100 and 200 mg kg-1) on a1-adrenoceptor agonist-induced contraction ...

we investigated the a,-adrenoceptor subtypes of rabbit saphenous vein which has a mixed functional population of α1 and α2 -adrenoceptors. lateral saphenous veins were obtained from male rabbits weighing 3.20-4 kg, which were killed by overdose with pentobarbitone sodium (i.v. injection). they were easily dissected out and placed in cold, oxygenated modified krebs-henselite solution (krebs). ea...

The β1-adrenoceptor exists in two agonist conformations/states: 1) a high-affinity state where responses to catecholamines and other agonists (e.g., cimaterol) are potently inhibited by β1-adrenoceptor antagonists, and 2) a low-affinity secondary conformation where agonist responses, particularly CGP12177 [(-)-4-(3-tert-butylamino-2-hydroxypropoxy)-benzimidazol-2-one] are relatively resistant t...

Adrenoceptor-mediated Cl- transport in cultured rabbit corneal endothelium was examined using a Cl(-)-sensitive fluorescent dye. The intracellular Cl- concentration ([Cl-]i) in the endothelial cells was estimated to be about 30 mM. Noradrenaline (0.001-0.1 mM) transiently decreased the [Cl-]i in a dose-dependent manner. Such a decrease in [Cl-]i was completely antagonized by pretreatment with t...

BACKGROUND Takotsubo cardiomyopathy (TCM) is characterized by regional left ventricular dysfunction that cannot be explained by an occlusive lesion in a coronary artery. Catecholamines are implicated in the pathogenesis of TCM but the mechanisms involved are unknown. Because the endogenous and the most commonly used exogenous catecholamines have well defined adrenoceptor subtype affinities, inf...

BACKGROUND AND PURPOSE CGP 12177 not only inhibits agonist effects mediated through the catecholamine site of the β1 -adrenoceptor with high affinity, but also exhibits agonist effects of its own at higher concentrations through a secondary, low-affinity β1 -adrenoceptor site or conformation. β-blocker affinities for this 'CGP 12177' site of the human β1 -adrenoceptor have thus far only been ch...

Nitric oxide (NO) is one of the most important immune molecules in innate immunity of invertebrates, and it can be regulated by norepinephrine in ascidian haemocytes. In the present study, the mutual modulation and underlying mechanism between norepinephrine and NO were explored in haemocytes of the scallop Chlamys farreri. After lipopolysaccharide stimulation, NO production increased to a sign...

Increased pressor responses to norepinephrine and other pressor agents have been reported to occur in human essential hypertension and in several animal models of experimental hypertension. These increased responses might be related to the development of hypertension or could be a secondary consequence of the elevation in blood pressure. We have examined pressor responses to alpha-adrenoceptor ...

The nomenclature of the Adrenoceptors has been agreed by NC-IUPHAR Subcommittee on [64, 194]. Adrenoceptors, α1 three α1-adrenoceptor subtypes α1A, α1B and α1D are activated endogenous agonists (-)-adrenaline (-)-noradrenaline. -(-)phenylephrine, methoxamine cirazoline prazosin doxazosin antagonists considered selective for α1- relative to α2-adrenoceptors. [3H]prazosin [125I]HEAT (BE2254) rela...

We investigated the a,-adrenoceptor subtypes of rabbit saphenous vein which has a mixed functional population of α1 and α2 -adrenoceptors. Lateral saphenous veins were obtained from male rabbits weighing 3.20-4 kg, which were killed by overdose with pentobarbitone sodium (i.v. injection). They were easily dissected out and placed in cold, oxygenated modified Krebs-Henselite solution (Krebs)...