The red cell adrenoceptor affinity for the unspecific agonists adrenaline and noradrenaline and the specific beta-agonist isoprenaline was studied in vitro on whole blood of rainbow trout, Salmo gairdneri at 15 degrees C. The erythrocytic adrenoceptors could be pharmacologically characterized as beta-receptors of the 'noradrenaline'-type (beta 1-type), with an order of potency of isoprenaline g...

To determine the structural basis for binding subtype selective agonists in the beta-adrenergic receptor (beta AR), we examined the interaction of the mutant beta 2AR and chimeric beta 1/beta 2AR with a selective beta 2AR agonist, TA-2005 (8-hydroxy-5-[(1R)-1-hydroxy-2-[N-[(1R)-2-(p-methoxyphenyl)-1-methyle thy l] amino]ethyl] carbostyril hydrochloride). The beta 2AR mutant with Ala substitute...

1. The whole-cell patch-clamp was used for studying the effects of various beta1- and beta2-adrenoceptor agonists and antagonists on the L-type Ca current (Ica) in frog ventricular myocytes. 2. Dose-response curves for the effects of isoprenaline (non selective beta-agonist), salbutamol (beta2-agonist), dobutamine (beta1-agonist) on ICa were obtained in the absence and presence of various conce...

Transcutaneous electrical nerve stimulation (TENS) is an analgesia inducing method with increasing applications in clinical procedures. In this study we tried to evaluate the role of the adrenergic system and its different adrenoceptor subtypes in TENS-induced analgesia. Two types of low and high frequency electrical stimuli were used in rats through needle electrodes, inserted at the base ...

Exposure of cells to adenosine receptor (AR) agonists leads to receptor uncoupling from G proteins and downregulation of the A(1)AR. The receptor levels on the cell surface generally recover on withdrawal of the agonist, because of either translocation of the sequestered A(1)AR back to plasma membrane or de novo synthesis of A(1)AR. To examine the mechanism(s) underlying A(1)AR downregulation a...

The importance of beta-adrenergic signaling in the heart has been well documented, but it is only more recently that we have begun to understand the importance of this signaling pathway in skeletal muscle. There is considerable evidence regarding the stimulation of the beta-adrenergic system with beta-adrenoceptor agonists (beta-agonists). Although traditionally used for treating bronchospasm, ...

Manocha and colleagues [1] found in a retrospective study on the association of beta-agonist use and lung injury a shorter duration and less severity of lung injury in patients on aerosolized beta-agonists. In their discussion of possible causes they and the investigators of the beta-agonist lung injury trial [2] did not comment on the effect of beta-agonist treatment on pulmonary chloride tran...

Three ELISA test kits, the Randox ELISA beta-agonist test kit, Euro-Diagnostica test kit, and Ridascreen beta-agonist test kit, were evaluated for screening of meat and liver for beta-agonist residues in fortified and field-incurred samples. It was found that the Randox beta-agonist test kit was more suitable as a screening tool due to its accuracy, ease of use, and lower cost. The tests were a...

BACKGROUND There is considerable controversy about the regular use of short-acting beta-agonists for the treatment of asthma. Although case-control studies have suggested that excessive use of these drugs may worsen asthma control and increase the risk of fatal or near-fatal asthma, the controversy remains unresolved because of the confounding that exists among disease control, disease severity...

Selective beta 2-agonist aerosols may produce significant cardiovascular effects. In the present study we used Holter monitoring to compare the arrhythmogenic effects of inhaled terbutaline (TE), a beta 2-agonist, with that of ipratropium bromide (IB), a nonabsorbable cholinergic drug. Fourteen patients with concomitant obstructive lung disease, ischemic heart disease, and complaints of postinh...