in this study using clonidine (a mixed ?2 /i1 receptors agonist), tizanidine (pure ?2-receptor agonist), rilmenidine (i1 receptor agonist) and yohimbine (?2-receptor antagonist), we tried to clarify the role of imidazoline and ?2-receptors in morphine withdrawal syndrome. morphine-dependence was induced by administration of increasing doses of morphine in mice. after the last administration of ...

The discovery of imidazoline ligands has opened up a new field of study. The investigation of imidazoline actions independent of adrenoceptors started in the mid 1980s. Imidazoline receptors are classified in several subtypes, I1, I2 and I3 binding sites. Although imidazoline sites have been the subjects of research for several years, but there is still controversy about their actions especiall...

In this study using clonidine (a mixed ?2 /I1 receptors agonist), tizanidine (pure ?2-receptor agonist), rilmenidine (I1 receptor agonist) and yohimbine (?2-receptor antagonist), we tried to clarify the role of imidazoline and ?2-receptors in morphine withdrawal syndrome. Morphine-dependence was induced by administration of increasing doses of morphine in mice. After the last administration of ...

In this study using clonidine (a mixed ?2 /I1 receptors agonist), tizanidine (pure ?2-receptor agonist), rilmenidine (I1 receptor agonist) and yohimbine (?2-receptor antagonist), we tried to clarify the role of imidazoline and ?2-receptors in morphine withdrawal syndrome. Morphine-dependence was induced by administration of increasing doses of morphine in mice. After the last administration of ...

The discovery of imidazoline ligands has opened up a new field of study. The investigation of imidazoline actions independent of adrenoceptors started in the mid 1980s. Imidazoline receptors are classified in several subtypes, I1, I2 and I3 binding sites. Although imidazoline sites have been the subjects of research for several years, but there is still controversy about their actions especiall...

The selectivity of tizanidine to the imidazoline-receptor and alpha 2-adrenoceptor recognized by 3H-p-aminoclonidine was examined in rat kidney membranes and was compared with those of other imidazoline compounds. Tizanidine bound to the imidazoline-receptors with approximately 20 times higher affinity than the alpha 2-adrenoceptors. The order of relative selectivity to imidazoline receptor was...

properties of agmatine and endogenous clonidine-displacing substance at imidazoline and alpha-2 adrenergic receptors. A. Imidazoline-guanidinium receptive site in renal proximal tubule: asymmetric distribution, regulation by cations and interaction with an endogenous clonidine displacing substance.idazoxan label different populations of imidazoline sites on rat kidney.

Large doses of the imidazoline alpha 2 adrenoreceptor agonist clonidine aggravate ethanol-induced gastric lesions. The alpha 2 adrenoceptor antagonist phentolamine, the opioid antagonist naloxone and the H2 antagonist cimetidine do not prevent this action of clonidine suggesting that it is not mediated by alpha 2, opioid or H2 receptors. Further, like clonidine, high doses of phentolamine and c...

BACKGROUND Numerous agents have been demonstrated to potentiate morphine analgesia, including clonidine (alpha(2)-adrenergic and I(1)-imidazoline receptor agonist) and BMS182874 (endothelin-A, ET(A,) receptor antagonist). ET has been shown to affect pharmacological actions of clonidine. The present study was conducted to determine whether alpha(2)-adrenergic and/or I(1)-imidazoline receptors ar...

Clonidine, moxonidine, and rilmenidine are centrally acting antihypertensive agents that lower arterial pressure by inhibiting the tonic activity of sympathoexcitatory neurons in the rostral ventrolateral medulla. Competing hypotheses have been put forward by different investigators to explain the sympathoinhibition evoked by "imidazoline drugs": either via central actions at α2-adrenergic rece...