Desensitization of adenylate cyclase-coupled beta-adrenergic receptors in avian erythrocytes results in a 40-65% decrease in agonist-stimulated adenylate cyclase activity and correlates with increased phosphorylation of beta-adrenergic receptors. To assess the role of phosphorylation in desensitization, membranes from isoprenaline- and dibutyryl cyclic AMP-desensitized turkey erythrocytes were ...

The bed nucleus of the stria terminalis (BNST) is one of the brain areas densely innervated by noradrenergic neurons originating in the brain stem. The present study aims to determine the role of noradrenergic receptors in the BNST in regulating pulsatile luteinizing hormone (LH) secretion in female rats. Ovariectomized (OVX) or estrogen-primed OVX (OVX+E2) rats received three 1-h-interval inje...

During stress, adrenergic signaling enhances cardiac conduction, although the mechanisms are not fully understood. Reducing extracellular calcium in heart widens an intercalated disc (ID) nanodomain adjacent to gap junctions known as perinexus. Under acute perinexus adaptively remodels; preventing this response by experimentally changing levels slows conduction and increases arrhythmia risk. Th...

The effects of crand ,-adrenergic stimulation on release of atrial natriuretic factor (ANF) were examined in seven anesthetized, open-chest pigs. The a-adrenergic agonist phenylephrine (28.0 ,ug/min) and the j3-adrenergic agonist isoproterenol (0.3 ,ug/min) were infused into the proximal part of the circumflex coronary artery to stimulate the left atrial adrenoceptors without concomitant change...

Clonidine is reported to inhibit the az-adrenoceptor mediated pinnal reflex in mice (3). Clonidine produces its effect by acting as an oc2-adrenergic autoreceptor agonist (1). As such, clonidine is also agonist for presynaptic histamine Hz-receptors (8). To test whether the clonidine-induced inhibition of the pinnal reflex is mediated through adrenergic and/or histaminergic system, the interact...

Scheiderer, Cary L., Lynn E. Dobrunz, and Lori L. McMahon. Novel form of long-term synaptic depression in rat hippocampus induced by activation of 1 adrenergic receptors. J Neurophysiol 91: 1071–1077, 2004. First published October 22, 2003; 10.1152/jn.00420.2003. Neurons located in the locus coeruleus project to hippocampus and provide noradrenergic innervation necessary for hippocampal-depende...

Phenylpropanolamine (dl-norephedrine) was one of the most widely used therapeutic agents to act on the sympathetic nervous system. Because of concerns regarding incidents of stroke, its use as a nasal decongestant was discontinued. Although considered an alpha1-adrenergic agonist, the vascular adrenergic pharmacology of phenylpropanolamine was not fully characterized. Unlike most other circulat...

Catecholamine, histamine, and adenosine-mediated accumulations of radioactive cyclic AMP were assessed in adenine-labeled slices from eight rat brain regions. 2-Fluoronorepinephrine, a selective beta-adrenergic agonist, elicited an an accumulation of cyclic AMP in cerebral cortex, cerebellum, hippocampus, striatum, superior colliculi, thalamus, hypothalamus, and medulla-pons. In cerebral cortex...

beta 1-Adrenergic receptors from turkey erythrocyte membranes have been identified by specific binding of the radiolabeled antagonist (-)-[3H]dihydroalprenolol. These receptors are inactivated by the alkylating agent N-ethylmaleimide when occupied by beta-adrenergic agonists but not when occupied by antagonists or when unoccupied. A time-dependent decrease of the number of receptor sites is obs...