In pithed spontaneous hypertensive rats, noradrenaline overflow was diminished by moxonidine even when α2-adrenoceptors were blocked quantitatively using phenoxybenzamine, suggesting an I1-receptor- mediated mechanism of noradrenaline release. This hypothesis was confirmed, since the noradrenaline overflow was (1) increased under α2-adrenoceptors blockade by the mixed I1/α2-antagonists efaroxan or idazoxan, (2) still reduced by moxonidine when both α2- and I1-receptors were blocked, and (3) diminished by agmatine after pretreatment with phenoxybenzamine, but not with AGN192403. An indirect ganglionic I1-receptor-mediated mechanism of noradrenaline release is supposed.
Research Areas and Centers
- Academic Focus: Center for Brain, Behavior and Metabolism (CBBM)