Endogenous noradrenaline re-uptake blocking factor in rats with reduced renal mass hypertension

This study was carried out to elucidate the involvement of the peripheral sympathetic nervous system in the pathogenesis of reduced renal mass (RRM)-salt hypertension in rats. Male Wistar rats underwent subtotal nephrectomy (70-80% reduction in renal mass). On the 10th postoperative day, systolic blood pressure was higher in RRM-salt rats than in RRM-water rats. Perfusion of isolated mesenteric vasculature from normotensive rats, with the deproteinized plasma from RRM-salt hypertensive rats induced significantly higher pressor responses and noradrenaline overflow with electrical stimulation than the perfusate from RRM-water normotensive rats; the responses to exogenous noradrenaline showed no significant changes. In the presence of desipramine, noradrenaline overflow did not increase following perfusion with plasma from RRM-salt hypertensive rats. These data indicate that plasma from rats with RRM-salt hypertension might contain some noradrenaline re-uptake blocking factor.