Treatment with desmethylimipramine (DMI), a tricyclic antidepressant, for 7 to 21 days resulted in a 35 to 45% decrease in the accumulation of adenosine cyclic 3':5'-monophosphate (cAMP) in response to a maximally effective concentration of (-)-isoproterenol (ISO) in rat cerebral cortical slices. The EC50 for ISO-stimulated cAMP accumulation was not affected by DMI administration. The diminutio...

BACKGROUND AND AIMS COX-2 enzyme inhibition is responsible for the anti-inflammatory effects of NSAIDs, COX-1 for their effects upon the gastrointestinal system (GIS), along with other side effects. We investigated the relationship between COX levels and those adrenergic receptors known to play a role in gastroprotection and anti-inflammatory activity. METHOD The effects of adrenaline and pre...

α(1)-Adrenergic receptor subtypes are widely distributed in the central nervous system and are involved in autonomic functions such as micturition. We investigated the presence and the role of supraspinal and/or spinal α(1)-adrenergic receptors in modulating the micturition reflex in conscious female Wistar rats. The expression of α(1)-adrenergic receptor subtypes in rat brain and lumbosacral s...

Renal nerve stimulation-induced antinatriuresis normally is mediated through postsynaptic oti-adrenergic receptors; however, prazosin-induced a,-adrenergic receptor blockade is associated clinically with sodium retention and not natriuresis. To study whether aradrenergic receptors mediate renal nerve stimulation-induced antinatriuresis after chronic prazosin treatment, Sprague-Dawley rats were ...

We have used two different cultured cell lines—S49 lymphoma cells and BC3H-1 muscle cells— to examine the regulation of /3-adrenergic receptors by receptor antagonists. Rather than an increase ("up-regulation") of receptor number that such antagonists often produce, we found that certain /3-blockers elicit a decrease ("down-regulation") of beta-adrenergic receptors. Alprenolol and propranolol, ...

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...

Recently, vast studies have been focused on the antinociceptive and anesthetic effects of α2 adrenergic receptors, using specific drugs such as medetomidine and dexmedetomidine. In the present study, we tried to assess the peripheral and central effects of dexmedetomidine in phasic and tonic pain, on rats, using tail flick and formalin tests. Dexmedetomidine, administered intraperitoneally (25,...

We have used wild-type and variants of the T-lymphoma cell line S49 to explore internalization and down-regulation of adenylate cyclase-linked beta-adrenergic receptors. Internalization was defined by the loss in "surface receptors" detected at 4 degrees C on intact cells by the antagonists [3H]CGP-12177 or [125I]iodocyanopindolol, whereas down-regulation was defined as the loss in total cellul...

In the isolated perfused hindlimb preparation of the dog, pressor responses to norepinephrine (NE) are mediated by postsynaptic alpha 1- and alpha 2-adrenergic receptors. Results obtained using preferential alpha 1- and alpha 2-adrenergic receptor antagonists suggest that the alpha 1-subtype is predominantly innervated while both alpha 1- and alpha 2-adrenergic receptor subtypes in vascular smo...