The importance of adrenergic receptors (ARs) in the hippocampus has generally focused on betaARs; however, interest is growing in hippocampal alphaARs given their purported neuroprotective role. We have previously reported alpha(1)AR transcripts in a subpopulation of cornu ammonis 1 (CA1) interneurons. The goal of this study was to identify the specific alpha(1)AR subtype (alpha(1A), alpha(1B),...

Evidence suggests that in some species (cats, rabbits, and possibly humans) alpha-adrenoceptors in the iris dilator muscle are "atypical" in that they cannot be readily classified by conventional criteria. This study was undertaken in an attempt to characterize the alpha-adrenoceptor subtype(s) mediating sympathetically elicited mydriasis in rats. Frequency-response pupillary dilator curves wer...

The binding subunit of the alpha 1-adrenergic receptor has been identified as an Mr = 80,000 peptide in several tissues. Adsorption of the alpha 1-adrenergic receptor to a wheat germ agglutinin lectin-agarose resin suggests that the receptor protein is glycosylated. In this study, we investigated the nature of the carbohydrate chains linked to the alpha 1-adrenergic receptor peptide. The alpha ...

Our laboratory has previously reported a decline in sympathetic nervous system restraint of skeletal muscle blood flow during prolonged mild-intensity exercise. This decline may be explained by a decrease in alpha(1)- and alpha(2)-adrenergic receptor responsiveness over time. Thus the purpose of the present study was to investigate the effect of exercise duration on alpha(1)- and alpha(2)-adren...

The action of adrenaline, noradrenaline and isoproterenol on the alpha-adrenergic receptor in the isolated tracheal muscle of guinea pigs was investigated by using a manometric procedure. An application of adrenaline or noradrenaline after the treatment with beta-adrenergic blocking agents caused a constriction of the tracheal muscle. The constrictive response could be inhibited by the pretreat...

For many years, -adrenergic receptor antagonists ( -blockers or AR antagonists) have provided significant morbidity and mortality benefits in patients who have sustained acute myocardial infarction. More recently, -adrenergic receptor antagonists have been found to provide survival benefits in patients suffering from heart failure, although the efficacy of different -blockers varies widely in t...

Quorum sensing is a cell-to-cell signaling mechanism in which bacteria respond to hormone-like molecules called autoinducers (AIs). The AI-3 quorum-sensing system is also involved in interkingdom signaling with the eukaryotic hormones epinephrine/norepinephrine. This signaling activates transcription of virulence genes in enterohemorrhagic Escherichia coli O157:H7. However, this signaling syste...

To elucidate the mechanisms responsible for the increase in alpha 1-adrenergic receptors during ischemia in vivo, we developed a procedure for measuring alpha 1-adrenergic receptors in isolated, calcium-tolerant adult canine myocytes. Specific [3H]prazosin binding was rapid, saturable, reversible, and demonstrated the expected order of potency and stereospecificity for the alpha 1-adrenergic re...

A series of 1-aminoalkyl-pyrrolo[2,3-c]azepin-8-one derivatives was synthesized and evaluated as alpha 1 adrenergic and serotonin 2 (5-HT2) receptor antagonists, with the aim of finding a novel antihypertensive agent potently exhibiting both activities. Some compounds with a 4-[4-(4-fluorobenzoyl)piperidino]butyl group at the 1-position exhibited both activities, and varied significantly in ter...

The best antihypertensive regimen for use in patients with mild-to-moderate hypertension has not been determined. When nonpharmacological treatment of hypertension fails, initial drug treatment with diuretic drugs, sympatholytic agents (including beta-adrenergic receptor blockers), or vasodilators will result in satisfactory blood pressure control. However, each of these therapies has effects t...