Both α2B- and α2C-adrenoceptor subtypes are involved in the mediation of centrally induced gastroprotection in mice.

α(2)-adrenoceptors are known to mediate gastroprotective effect in both acid-dependent and acid-independent ulcer models. The aim of the present study was to determine, which of the three α(2)-adrenoceptor subtypes (α(2A), α(2B) or α(2C)) is responsible for this protection. Various α(2)-adrenoceptor agonists and antagonists were administered intracerebroventricularly (i.

Nocistatin and nociceptin given centrally induce opioid-mediated gastric mucosal protection.

Nociceptin (N/OFQ) and nocistatin (NST) are two endogenous neuropeptides derived from the same precursor protein, preproN/OFQ. The aim of the present work was to study the effect of NST on the ethanol-induced mucosal damage compared with that of N/OFQ following intracerebroventricular (i.c.

alpha2B-adrenoceptor agonist ST-91 antagonizes beta2-adrenoceptor-mediated relaxation in rat mesenteric artery rings.

We sought an isolated vascular preparation and experimental setting where the function of alpha2B-adrenoceptors could be demonstrated by non-recombinant technique. ST-91 (2-[2,6-diethylphenylamino]-2-imidazoline), an alpha 2B-adrenoceptor agonist with a mixed alpha adrenergic receptor type/subtype selection profile antagonized the relaxant effect of isoproterenol in endothelium-denuded rat mesenteric artery rings precontracted with phenylephrine. At 10(-7) M of ST-91, the antagonism was characterized by a rightward shift of isoproterenol dose-response curve (A50=6.

Analysis of the role of central and peripheral alpha2-adrenoceptor subtypes in gastric mucosal defense in the rat.

The present study confirmed our previous assumption on the crucial role of central alpha2B-like adrenoceptor subtype in gastric mucosal defense. It was found that beside clonidine, rilmenidine, an alpha2/imidazoline receptor agonist and ST-91, an alpha2B-adrenoceptor preferring agonist inhibited the mucosal lesions induced by ethanol given intracerebroventricularly (i.c.

Pre- and postsynaptic mechanisms in the clonidine- and oxymetazoline-induced inhibition of gastric motility in the rat.

The inhibitory effect of clonidine (non-selective alpha2-adrenoceptor agonist) and oxymetazoline (alpha2A-adrenoceptor selective agonist) was compared on basal and stimulated gastric motor activity (gastric tone and contractions) using the balloon method in the rat. It was shown that oxymetazoline (0.2-1.