Many studies have suggested that alpha-adrenergic receptors on vascular smooth muscle are heterogeneous and that both alpha 1- and alpha 2-adrenergic receptors can cause vasoconstriction when stimulated. We explored this hypothesis in normal humans by comparing the capacity of yohimbine, an alpha 2-adrenergic receptor antagonist, and prazosin, an alpha 1-adrenergic receptor agonist, with differ...

PURPOSE To investigate expression of muscarinic, cholinergic, and adrenergic receptors on developing conjunctival goblet cells. METHODS Eyes were removed from rats 9 to 60 days old, fixed, and used for microscopy. For glycoconjugate expression, sections were stained with Alcian blue/periodic acid-Schiffs reagent (AB/PAS) and with the lectins Ulex europeus agglutinin I (UEA-I) and Helix pomati...

I N 1964 Oj-adrenergic receptors were first described pharmacologically using the in vitro melanocyte granule dispersion technique in Rana pipiens. The goal of these studies was to assess the intrinsic activity on o^-adrenergic receptors of methyldopa's neurotransmitter metabolites and other catecholamines. Publication of this description was delayed for 13 years, 1 until the evidence for a rec...

Experimental studies in preclinical mouse models of breast cancer have shown that chronic restraint stress can enhance disease progression by increasing catecholamine levels and subsequent signaling of β-adrenergic receptors. Catecholamines also signal α-adrenergic receptors, and greater α-adrenergic signaling has been shown to promote breast cancer in vitro and in vivo. However, antagonism of ...

The closely related G protein-coupled receptor kinases GRK2 and GRK3 are both expressed in cardiac myocytes. Although GRK2 has been extensively investigated in terms of regulation of cardiac beta-adrenergic receptors, the substrate specificities of the two GRK isoforms at G protein-coupled receptors (GPCR) are poorly understood. In this study, the substrate specificities of GRK2 and GRK3 at GPC...

The thiazide-sensitive sodium-chloride-cotransporter (NCC) in the kidney distal convoluted tubule (DCT) plays an essential role sodium and potassium homeostasis. Here, we demonstrate that NCC activity is increased by β2-adrenoceptor agonist salbutamol, a drug prevalently used to treat asthma. Relative β1-adrenergic receptors, β2-adrenergic receptors were greatly enriched mouse DCT cells. In mic...

I N 1964 Oj-adrenergic receptors were first described pharmacologically using the in vitro melanocyte granule dispersion technique in Rana pipiens. The goal of these studies was to assess the intrinsic activity on o^-adrenergic receptors of methyldopa's neurotransmitter metabolites and other catecholamines. Publication of this description was delayed for 13 years, 1 until the evidence for a rec...

Protein kinases play a pivotal role in the propagation and modulation of transmembrane signaling pathways. Two major classes of receptors, G-protein-linked and tyrosine kinase receptors not only propagate signals but also are substrates for phosphorylation in response to stimulation by agonist ligands. Insulin (operating via tyrosine kinase receptors) and catecholamines (operating by G-protein-...

A procedure has been developed for purification of the porcine brain alpha 2-adrenergic receptor to homogeneity. alpha 2-Adrenergic receptors were solubilized from porcine brain particulate preparations using sequential extraction into sodium cholate- and digitonin-containing buffers. The alpha 2-adrenergic receptors in the digitonin extract were identified using the alpha 2-adrenergic selectiv...