Antihypertensive activity of 2-amino-4-(3,4-dichlorophenyl)-2-imidazoline (MJ 10459-2) and catecholamine reduction

Antihypertensive activity of 2-amino-4-(3,4-dichlorophenyl)-2-imidazoline hydrobromide (MJ 10459-2) was assessed in conscious, spontaneously hypertensive and stress-induced hypertensive rats via indirect determination of systolic blood pressure. Subcutaneous administration of 1-4 mg/kg resulted in lowering of blood pressure that was dose related. No reductions in the content of norepinephrine, dopamine, serotonin or 5-hydroxyindoleacetic acid were noted in the cerebrum, cerebellum, midbrain or medulla/pons area of brain after 1 and 4 mg/kg of MJ 10459-2. Cardiac tissue norepinephrine was reduced to 4-6% of control values after subcutaneous doses of 0.2-20 mg/kg of MJ 10459-2 in hypertensive and normotensive rats. These data suggest that at least part of the blood pressure lowering effects of MJ 10459-2 may involve reduction of peripheral noradrenergic stores.