Contrast medium-induced pulmonary vascular hyperpermeability is aggravatedin a rat climacterium model

RATIONALE AND OBJECTIVES, TO test whether climacterium influences adverse p ulmonary reactions to contrast media, the authors investigated the effect o f ioxaglate on pulmonary vascular permeability in ovariectomized rats as a climacterium model. METHODS. From 7 days after surgery, ovariectomized rats were treated with e stradiol valerate or vehicle once per week for 3 weeks. At 28 days after su rgery, ioxaglate, an ionic contrast medium, was intravenously injected at 1 .5 mL/min in rats. Pulmonary vascular permeability was evaluated by measuri ng the amount of Evans blue dye in the lung tissue. RESULTS. Ioxaglate dose-dependently increased pulmonary vascular permeabili ty in sham-operated and ovariectomized rats. Ovariectomized rats showed a 2 .6-fold increased aggravation of vascular permeability by ioxaglate 4 g I/k g compared with sham-operated rats. Estradiol valerate (0.2-5.0 mg/kg) dose -dependently blocked ioxaglate-increased vascular permeability in ovariecto mized rats. CONCLUSIONS. These findings suggest that climacterium is included, at least in part, in the risk factors for contrast-induced adverse pulmonary reacti ons, and this risk is lowered by estrogen replacement therapy.