Prevention of aconitine-induced neurogenic pulmonary edema (NPE) with hypovolemia or methylprednisolone.

Bilateral injections of aconitine in the preoptic-anterior hypothalamic area in rats produces pulmonary edema that is mediated by neurogenic mechanisms. The aim of the present study was to determine the efficacy of hypovolemia or intravenous methylprednisolone on preventing aconitine-induced pulmonary edema. Rats made hypovolemic before or after injection of aconitine or treated with 40 mg/kg methylprednisolone had normal lung weight-to-body weight ratios (LW/BW) and normal pulmonary ultrastructure. In contrast, high LW/BW and gross ultrastructural alterations were noted in rats injected with aconitine only. These findings suggest that hypovolemia was effective in preventing aconitine-induced neurogenic pulmonary edema (NPE) because it lowered the pulmonary blood volume and that methylprednisolone provided a beneficial effect by suppressing the hemodynamic response involved in NPE or by directly stabilizing the cell membranes.