Etiopathogenesis of excess methylprednisolone arterial hypertension in the rat.

The blood pressure response to different doses of methylprednisolone was examined in the rat. It is concluded that doses varying from 2.5 mg/kg/week to 20 mg/kg/week of this agent caused clear-cut elevations in arterial pressure. The methylprednisolone-induced arterial hypertension was accompanied by elevation in Plasma Renin Activity and administration of captopril or saralasin caused significant drops in systemic arterial pressure. Concomitant long term administration of captopril and methylprednisolone caused a delay in appearance and smaller elevations in arterial pressure. It is concluded the methylprednisolone in the rat causes arterial hypertension which is at least partially dependent upon renin angiotensin system activation. However elevated blood pressure levels were noticeable even during chronic captopril administration leading to the conclusion that other mechanism (s) may participate in the pathogenesis of this experimental model of hypertension in rats.