Incidence of epinephrine-induced pulmonary edema in rabbits and accompanying metabolic changes

Searching for an experimental condition to produce pulmonary edema of uniform high grade severity in rabbits, five different doses of epinephrine (38,60, 100, 160 and 260 mug/ml) were infused at a rate of 0.29 ml/min for 20 min into the femoral vein of fed and fasted animals. Body temperature was maintained at 38 to 40 degrees C. The incidence of pulmonary edema was not dose-dependent, and was approx. 70% by the administration of 60 to 260 mug/ml of epinephrine solutions. In general, the edema was more severe in the fed group than in the fasted. The highest dose of epinephrine was often fatal in the fasted group. One hundred mug/ml (approx. 10 mug/kg/min), fed was regarded as a favourable condition for the experiment. The amounts of lung lipids increased in edema (+) cases of the fed groups. The plasma potassium level was elevated in proportion to the dose of epinephrine. The clotting time of blood was markedly prolonged in edema (+) rabbits. The significance of these observations was discussed in regard to the mechanism of epinephrine-induced pulmonary edema.