Ipratropium bromide is an anticholinergc bronchodilator administered by inhalation. Although producing bronchodilation in most patients with obstructive airways disease, it is somewhat less effective than beta 2-adrenoceptor agonist drugs such as salbutamol or fenoterol in patients with asthma, but is at least as effective as these agents in bronchitis. As with the beta 2-adrenoceptor agonists,...

Chronic treatment with β 2 adrenoceptor agonists is recommended as a first-line maintenance therapy for chronic obstructive pulmonary disease (COPD). However, a potential consequence of long-term treatment may be the loss of functional response (tachyphylaxis) over time. In this study, we have investigated the tendency of such agonists, with a range of efficacies, to develop functional desensit...

Background—Coronary vessel tone is modulated in part by -adrenergic relaxation. However, the implication of specific -adrenoceptor subtypes and their downstream vasorelaxing mechanism(s) in human coronary resistance arteries is poorly defined. 3-Adrenoceptors were recently shown to vasodilate animal vessels and are expressed in human hearts. Methods and Results—We examined the expression and fu...

In this study, three lines of evidence suggest a role for α(2)-adrenoreceptors in rat pup odor-preference learning: olfactory bulb infusions of the α(2)-antagonist, yohimbine, prevents learning; the α(2)-agonist, clonidine, paired with odor, induces learning; and subthreshold clonidine paired with subthreshold β-adrenoceptor activation also recruits learning. Increased mitral cell layer pCREB o...

β-blockers are widely used to improve symptoms and prolong life in heart disease primarily by inhibiting the actions of endogenous catecholamines at the β1-adrenoceptor. There are two common naturally occurring polymorphisms within the human β1-adrenoceptor sequence: Ser or Gly at position 49 in the N-terminus and Gly or Arg at position 389 in the C-terminus and some clinical studies have sugge...

Xylazine hydrochloride, α2 adrenoceptor agonist, is an analgesic, sedative, tranquilizer, and muscle relaxant agent in veterinary medicine which is mostly used as in pre-anesthesia in veterinary medicine. One of the main adverse effects of xylazine which limits application of this medication in small animal veterinary practice (mostly in cats) is nausea and vomiting which can end up with aspira...

ρ-Da1a is a three-finger fold toxin from green mamba venom that is highly selective for the α1A-adrenoceptor. This toxin has atypical pharmacological properties, including incomplete inhibition of (3)H-prazosin or (125)I-HEAT binding and insurmountable antagonist action. We aimed to clarify its mode of action at the α1A-adrenoceptor. The affinity (pKi 9.26) and selectivity of ρ-Da1a for the α1A...

The hyperkalaemic action of adrenaline was investigated in 44 anaesthetized domestic pigs. Plasma and epicardial concentrations of K were measured, in the latter case with an ion-selective electrode. Adrenaline 10 pgkg~ caused a rapid increase in the plasma concentration of K from 4.2 to 5.9 mmol litre'. The magnitude and the time course of epicardial concentration of K were similar. Alpha-adre...

Although noradrenaline (NA), a stress-associated neurotransmitter, seems to affect the immune system, the precise mechanisms underlying NA-mediated immunoregulation are not fully understood. We examined the effect of NA on Ag uptake (endocytosis) by dendritic cells (DCs) using murine bone marrow-derived DCs and fluorescence-labeled endocytic tracers (dextran and OVA). Ag uptake by DCs notably i...

OBJECTIVES This study evaluated cardiac beta-adrenoceptor responsiveness in the elderly. BACKGROUND The hypothesis of reduced cardiac beta-adrenoceptor responsiveness in the elderly is based on a smaller increase in heart rate after administration of isoproterenol, a nonselective beta 1- and beta 2-adrenoceptor agonist. By means of dobutamine-stress-echocardiography we were able to retest the...