beta(2)-Adrenoceptor agonists are the most effective bronchodilators currently available, and are used for symptom management in asthmatics. However, whether beta(2)-agonists are also antitussive is controversial. Identifying an antitussive role for beta(2)-agonists and dissecting the possible mechanism of action may help to explain the inconsistencies in the clinical literature and lead to the...

The ovarian hormones estradiol (E(2)) and progesterone (P) facilitate rat lordosis behavior in part by regulating the expression of and signal transduction by adrenoceptors in the hypothalamus (HYP) and preoptic area (POA). The major adrenoceptor subtype mediating E(2) and P facilitation of lordosis is the alpha(1)-adrenoceptor. In the present studies, we tested the hypotheses that (1) alpha(1)...

BACKGROUND It is well known that during cardiopulmonary bypass (CPB) with cardioplegic cardiac arrest, catecholamines are vigorously increased. We therefore investigated whether this might cause desensitization of human cardiac beta-adrenoceptors. METHODS AND RESULTS We assessed in 12 children with acyanotic congenital heart disease who underwent open-heart surgery right atrial beta-adrenocep...

Basal contractility and responses to beta-adrenoceptor activation are compromised in hearts from rats with chronic portal vein stenosis. Here we report the effect of partial ligation of the portal vein on myocardial G protein expression, beta-adrenoceptor-G protein coupling, and excitation-contraction coupling (ECC). Contractility (dT/dt) was reduced 30-50% in right and left ventricles, but the...

β-Adrenoceptor activation increases intracellular cAMP levels and consequently induces exocytotic amylase release in parotid acinar cells. Phosphodiesterase (PDE) catalyses the hydrolysis of cAMP, which terminates the downstream signaling of this second messenger. We investigated the involvement of PDE4, a cAMP-PDE, in β-adrenoceptor agonistinduced amylase release in mouse, rat and rabbit parot...

In this study, we examined whether Sprague-Dawley rats obtained from two different vendors, Harlan and Sasco, differ with respect to the types of alpha-2 adrenoceptors in the spinal cord that mediate antinociception. This hypothesis was tested using two alpha-2 adrenoceptor agonists, dexmedetomidine and ST-91, which are relatively selective for alpha-2A and alpha-2B adrenoceptors, respectively,...

In this study, to test the hypothesis that adrenergic vasoconstrictor responses of the legs are greater compared with the arms in human skin, cutaneous vascular conductance (CVC) in the forearm and calf were compared during the infusion of adrenergic agonists in healthy young volunteers. Under normothermic conditions, norepinephrine (NE, α- and β-agonist, 1 × 10(-8) to 1 × 10(-2) M), phenylephr...

Patients in the intensive care unit frequently experience delirium, anxiety, and agitation, with a variety of treatments used. This article discusses the role of an alpha-adrenoceptor agonist, dexmedetomidine, and its clinical relevance and advantages for the agitated patient.