The effect of warming on adrenergic neurotransmission was examined in canine cutaneous veins. Isometric tension was recorded from rings of saphenous veins of the dog in organ chambers filled with physiological salt solution. During contractions caused by potassium or prostaglandin F2 alpha, warming from 37 to 41 degrees C caused an augmentation. During contractions caused by stimulation of the ...

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...

We investigated the effects of restraint and footshock stress and norepinephrine treatment on gastric emptying. The gastric emptying was significantly inhibited by restraint stress. beta(3)-adrenergic antagonist canceled the inhibition of gastric emptying caused by restraint stress, while beta(1)-, beta(2)-, alpha(1)-, and alpha(2)-adrenergic antagonists did not affect the inhibition. Norepinep...

Influences of central alpha-2 adrenergic agonists on thyrotropin-releasing hormone (TRH)-stimulated gastric acid secretion were examined in the perfused stomach of anesthetized rats. Clonidine, an alpha-2 adrenergic agonist, given subcutaneously or intracerebroventricularly inhibited the gastric acid secretion stimulated by intracerebroventricular TRH. Intracerebroventricular injection of norep...

In the search for the existence of adrenergic regulation of the autocrine/paracrine function of the white adipose tissue, it was observed that conditioned media from isolated adipocytes or dialysates obtained by in situ microdialysis of human subcutaneous adipose tissue increased spreading and proliferation of 3T3F442A preadipocytes. These effects were amplified when an alpha 2 -adrenergic agon...

PURPOSE To identify and characterize the alpha-2 adrenergic receptor subtypes present in the bovine neurosensory retina. METHODS Radioligand saturation and inhibition binding assays were performed with the antagonist radioligands [3H]RX821002 and [3H]rauwolscine. RESULTS [3H]RX821002 bound to a single class of receptors with the characteristics of an alpha-2 adrenergic receptor with an affi...

To identify a physiological role for renal alpha 2 adrenergic receptors, renal vascular and tubular responses to administration of graded frequencies of renal nerve stimulation or graded doses of adrenergic agonists were determined in anesthetized spontaneously hypertensive, Wistar-Kyoto, and Sprague-Dawley rats. Renal vasoconstrictor responses to renal nerve stimulation and alpha 1-adrenergic ...

We previously reported that alpha(2)-adrenergic receptor (alpha(2)-AR) stimulation in Purkinje fibers in vitro prolongs action potential duration and suppresses beta-adrenergic-induced delayed afterdepolarizations and sustained triggered activities. We examined the effects of alpha(2)-AR stimulation on reperfusion-induced ventricular arrhythmias [ventricular tachycardia/ventricular fibrillation...