There is evidence indicating that adrenoceptor mechanisms may influence some of the behaviors in rat. However the role of adrenoceptor agents on sniffing has not been identified. In the present study, the influence of adrenoceptor agents on sniffing induced by apomorphine and amphetamine has been investigated. Male Albino rats, weighing 150-250 g were used for all experiments. The behavior wa...

Despite over two decades of research, the molecular identity of the α1L-adrenoceptor phenotype has remained elusive. Gray et al. (2008) present results in this issue of the journal that provide persuasive evidence that the in vivo α1L-adrenoceptor phenotype requires the expression of the α1A-adrenoceptor gene. They have shown that in mice lacking the functional α1A-adrenoceptor gene, α1L-mediat...

We determined the binding affinity of tamsulosin, a selective α(1)-adrenoceptor antagonist, for human α(1)-adrenoceptor subtypes in comparison with those of other α(1)-adrenoceptor antagonists including silodosin, prazosin, 5-methylurapidil, terazosin, alfuzosin, nafopidil, urapidil and BMY7378. The association and dissociation kinetics of [(3)H]tamsulosin for recombinant human α(1)-adrenocepto...

Alternative splicing of mouse beta3-adrenoceptor transcripts produces an additional receptor isoform (beta3b-adrenoceptor) with a C terminus comprising 17 amino acids distinct from the 13 in the known receptor (beta3a-adrenoceptor). We have shown that the beta3b-adrenoceptor couples to both Gs and Gi, whereas the beta3a-adrenoceptor couples only to Gs. To define the regions involved in this dif...

It has been shown that inflammation reduces the effectiveness of sympathetic nerves in the regulation of knee joint blood flow, and the joint vascular- ß adrenoceptors are changed due to acute inflammation from a majority of ß-1 to an equality of ß-1 and ß-2 receptors.. To investigate the role of sympathetic nerves in nerve induced vasoconstriction and changes in joint vascular ß-adrenoceptors ...

The hypothesis that exercise-induced coronary vasodilation is a result of sympathetic activation of coronary smooth muscle beta-adrenoceptors was tested. Ten dogs were chronically instrumented with a flow transducer on the circumflex coronary artery and catheters in the aorta and coronary sinus. During treadmill exercise, coronary venous oxygen tension decreased with increasing myocardial oxyge...

It has been suggested that there is a link between epinephrine synthesis and the development of β2-adrenoceptor-mediated effects, but it remains to be determined whether this development is triggered by epinephrine. The aim of this study was to characterize β-adrenoceptor-mediated relaxation and facilitation of norepinephrine release in the aorta of phenylethanolamine-N-methyltransferase-knocko...

It has been suggested that there is a link between epinephrine synthesis and the development of b2-adrenoceptor–mediated effects, but it remains to be determined whether this development is triggered by epinephrine. The aim of this study was to characterize b-adrenoceptor–mediated relaxation and facilitation of norepinephrine release in the aorta of phenylethanolamine-Nmethyltransferase–knockou...

BACKGROUND AND PURPOSE alpha(1)-Adrenoceptor agonists induce Ca(2+)-transients in endothelial cells (ECs) of arterioles. However, the presence of alpha(1)-adrenoceptors on arteriolar ECs has not been excluded, and the identity of alpha(1)-adrenoceptor subtypes in arterioles only has been inferred from pharmacology. Therefore, we determined which subtypes were expressed by vascular smooth muscle...

The effects of indoramin, a selective alpha 1 adrenoceptor antagonist, on exercise tolerance were studied in 15 patients using a random double blind crossover protocol. All patients had chronic stable angina, for which 13 had been receiving beta adrenoceptor blocking drugs and nitrates, and these were continued unchanged throughout the study. An initial open challenge with indoramin in eight pa...