The title compound tetraphenylborate salt of clonidine (Catapres®), 2-(2,6-dichlorophenylamino)-2-imidazoline (3), was prepared in 76 % yield by the reaction hydrochloride (clonidine hydrochloride) (1) with sodium (2) deionized water through anion exchange at ambient temperature. structure borate characterized UV, thermal analysis, mass and NMR analyses. White crystals (3) suitable for an X-ray...

The sympathetic nervous system plays a central role in the pathophysiology not only of hypertension and other cardiovascular diseases but also metabolic disorders including disturbances of glucose and lipid homeostasis. A centrally acting sympathetic agent is therefore attractive not only for lowering blood pressure, but also intervening with multiple disease processes. Older agents such as clo...

Norepinephrine has powerful and diverse modulatory effects on hypoglossal (XII) motoneuron activity, which is important in maintaining airway patency. The objective was to test two hypotheses that alpha2-adrenoceptor-mediated, presynaptic inhibition of glutamatergic inspiratory drive (Selvaratnam SR, Parkis MA, and Funk GD. Brain Res 805: 104-115, 1998) and postsynaptic inhibition of the hyperp...

The I1 subtype of imidazoline receptors (I1R) is a plasma membrane protein that is involved in diverse physiological functions. Available radioligands used so far to characterize the I1R were able to bind with similar affinities to 2-adrenergic receptors ( 2-ARs) and to I1R. This feature was a major drawback for an adequate characterization of this receptor subtype. New imidazoline analogs were...

Over the past few years, a vast amount of research has shed light on the pharmacology of imidazoline binding sites (I-BS). To date, at least three classes of imidazoline binding sites have been characterised in accordance to their localisation, drug selectivity, proposed signalling pathways and functional roles. The existence of these sites raises the question as to whether an endogenous modula...

Interruption of long-term treatment with alpha 2-adrenergic receptor agonists may be associated with reversal of their hemodynamic effects, clinical and biochemical evidence of increased peripheral sympathetic activity, and behavioral responses similar to those seen after narcotic or alcohol withdrawal. Reactions are most commonly observed after short-acting imidazoline drugs such as clonidine ...

Interruption of long-term treatment with a2-adrenergic receptor agonists may be associated with reversal of their hemodynamic effects, clinical and biochemical evidence of increased peripheral sympathetic activity, and behavioral responses similar to those seen after narcotic or alcohol withdrawal. Reactions are most commonly observed after short-acting imidazoline drugs such as clonidine and t...

The imidazoline system consists in imidazoline receptors I1, I2 and I3 and the active as well as that there are some endogenous ligands. We consider that one of the most important functions of this system is modulation of different types of behavior. Existent data show that I1 and I2 receptors have different effects on some behavior components, such as suicidal behavior, stress, anxiety, food i...

the involvement of supraspinal alpha-adrenergic receptors in tonic pain was assessed in formalin-induced pain in rats. the alpha2 adrenoceptor agonist clonidine, along with yohimbine and prazosin, α2 and α1 receptor antagonists, were introduced intracerebroventrically (icv) and/or systemically in different doses. the data show that 1) clonidine exerts an alpha adrenergic analgesic effect, in ad...