G-protein-coupled receptors (GPCRs) mostly signal through heterotrimeric G proteins. Increasing evidence suggests that GPCRs could function in a G-protein-independent manner. Here, we show that at low concentrations of an agonist, beta(2)-adrenergic receptors (beta(2)-ARs) signal through Galpha(s) to activate the mitogen-activated protein kinase pathway in mouse embryonic fibroblast cells. At h...

The glycogen body (GB) is at the dorsal area of the lumbosacral spinal cord in birds and is composed of uniform cells that are characterized by high-glycogen storage. Previous morphological and embryological examinations suggest that the GB is derived from the neuroepithelium and contains many blood vessels and a few nerve fibers. However, the function of the GB and role of the glycogen are unk...

It is widely recognized that Th2 cytokines derived from T cells play a major role in the development of allergic lung inflammation that causes most asthma. Beta-agonists are important rescue and maintenance therapies for asthma, yet our understanding of beta-agonist effects on T cell biology is surprisingly poor. Recent studies using both cell culture and more integrative models are beginning t...

BACKGROUND AND OBJECTIVE Use of beta(2)-adrenergic receptor agonists has been advocated for the treatment of hypoglycemia unawareness in type 1 diabetes. In vitro, however, hypoglycemia unawareness has been associated with reduced beta(2)-adrenergic sensitivity. Therefore, in vivo sensitivity to beta(2)-adrenergic receptor agonist stimulation was compared between type 1 diabetic patients with a...

The whole-cell patch-clamp and intracellular perfusion techniques were used for studying the effects of a beta-2 adrenergic receptor activation on the L-type Ca current (ICa) in frog ventricular myocytes. The beta-2 adrenergic agonist zinterol increased ICa in a concentration-dependent manner with an EC50 (i.e., the concentration of zinterol at which the response was 50% of the maximum) of 2.2 ...

The beta 2-adrenergic receptor (beta 2AR) belongs to the large family of G protein-coupled receptors. Mutation of tyrosine residue 326 to an alanine resulted in a beta 2AR mutant (beta 2AR-Y326A) that was defective in its ability to sequester and was less well coupled to adenylyl cyclase than the wild-type beta 2AR. However, this mutant receptor not only desensitized in response to agonist stim...

To characterize age-related changes in beta-adrenergic responsiveness and to test the hypothesis that an increase in the effects of adenosine contribute to impaired beta-adrenergic responsiveness, Fischer 344 rat right atria (RA), left atria (LA), and left ventricular trabeculae carnae were exposed to the beta-receptor agonist isoproterenol (ISO), followed by four doses of the selective adenosi...

Different beta 1 and 2 adrenergic receptors agonists might have various biological and physiological effects on fish species. An experiment was designed to study the effects of feeding ractopamine, terbutaline and metaproterenol; as beta1, beta2 and less selective beta2 adrenergic receptor agonists, respectively; on body weight gain, feed conversion rate, concentration of biochemical parameters...