Hypertension is an independent risk factor of cardiovascular diseases. Several factors contribute to its development, including chronic stress, which may induce hypertension by increasing sympathetic activity. The signs of increasing sympathetic activity can be primarily detected in the initial phase of hypertension, which is characterized by the increase in cardiac output. In addition to the h...

Although originally developed for the treatment of hypertension, a2agonists have been used to treat Tourette’s syndrome, attention-deficit hyperactivity disorder (ADHD), developmental disorders and substance abuse for nearly three decades. Based on studies of clonidine, a2-agonists were presumed to reduce arousal by decreasing the firing of noradrenaline neurons in locus ceruleus. Accumulated p...

Vigorous exercise transiently increases the risk of primary cardiac arrest. Strenuous, acute exercise can also increase the release of plasma epinephrine. Previous investigations have indicated that epinephrine can potentiate platelet activation by activating platelet alpha2-adrenoceptors. This study investigated how strenuous, acute exercise affects alpha2-adrenergic agonist-potentiated platel...

Vigorous exercise transiently increases the risk of primary cardiac arrest. Strenuous, acute exercise can also increase the release of plasma epinephrine. Previous investigations have indicated that epinephrine can potentiate platelet activation by activating platelet a2-adrenoceptors. This study investigated how strenuous, acute exercise affects a2-adrenergic agonist– potentiated platelet acti...

Functional role of endothelial alpha(2)-adrenoceptor in coronary circulation remains unclear. Clonidine, an agonist of alpha(2)-adrenoceptors, was reported to induce coronary vasodilatation via stimulation of endothelial alpha(2)-adrenoceptors or coronary vasoconstriction involving vascular smooth muscle alpha(2)-adrenoceptors. Moreover, H(2) receptor-dependent responses to clonidine were descr...

We have examined the effects of intrathecal (i.t.) injection of the muscarinic acetylcholine receptor antagonist atropine on the clonidine-induced nociceptive effect in formalin-induced nociception in rats. The injection of 5% formalin into the hind paw caused biphasic nociceptive responses, and i.t. injection of clonidine inhibited both phases of the nociceptive response in a dose-dependent ma...

Effects of agmatine, an endogenous metabolite formed by decarboxylation of L-arginine, on ethanol-induced gastric mucosal injury were investigated in rats. Agmatine at 1 and 10 mg/kg i.p doses significantly increased ethanol-induced gastric mucosal injury. This effect of agmatine was abolished completely by pretreatment with idazoxan, an imidazoline receptor-antagonist and alpha2 receptor- anta...