Although many reports have accumulated concerning the adrenaline pulmonary edema, including notable papers by Luisada, its pathogenetic mechanism has not been sufficiently clarified experimentally. The author studied the problem of adrenaline pulmonary edema chiefly from the aspect of the pulmonary lymph circulation, and obtained the following results.I. The effect of the intravenously administered adrenaline on the pulmonapy lymph circulation.Methods : Adult dogs weighing 7 to 12 kg under anesthesia were injected with adrenaline intravenously and examined for the pulmonary lymph flow, the protein concentration in the lymph, femoral artery blood pressure and rate of respiration. Animals were divided into 4 groups according to the dose of adrenaline injected ; i.e., 0.2 mg/kg, 0.5 mg/kg, 1 mg/kg, and 2 mg/kg, and each injection took about 30-60 seconds.Results : With small doses of adrenaline (1 mg/kg or less) the pulmonary lymph flow was unchanged. With 2 mg/kg injected intravenously, the pulmonary lymph flow was increased 2 folds up to 25 times original rate. The lymph became macroscopically hemorrhagic. The protein concentration in the lymph was increased both in the group of 1 mg/kg and that of 2 mg/kg. The femoral artery pressure and the rate of respiration were reduced throughout different groups. Since 2 mg/kg of adrenaline was found to always and un-mistakably increase the lymph flow, this dose of adrenaline was used in the following part of the experiment to increase the rate of the lymph flow.II. The effect of the artificial respiration on the pulmonary lymph circulation under the influence of the intravenous adrenaline.Since the respiratory movement gravely affects the pulmonary lymp flow, as was shown in the preceding chapter, it appears necessary to evaluate the extent to which the state of apnea or reduced respiration accompanying the injection of adrenaline may have diminished the otherwise increased pulmonary lymph flow under this circumstance. To study this point, the action of adrenaline to change the rate of respiration was eliminated by keeping the animals under the artificial respiration.Methods : The conditions of the artificial respiration were set in such way that animals were placed under something very close to the natural respiration ; and adrenaline was injected only after the initial fluctuations in the pulmonary lymph flow due to the switching to artificial respiration have disappeared, and the rate of the lymph flow became stabilized.Restlts : The rate of pulmonary lymph flow began to increase immediately following the intravenous injection of adrenaline, there was no transient period of decreased lymph flow, such as noted previously owing to the adrenaline-induced apnea. This observation made it clear that the transient decrease in the pulmonary lymph flow with the intravenous injection of adrenaline was secondary to the change in the respiratory movement.III. The effect of the repeated injection of adrenaline on the pulmonary lymph circulation.Method : After a single injection of adrenaline caused the pulmonary lymph flow to increase and then return to the initial level, the same dose of adrenaline was injected repeatedly.Results : If adrenaline was injected in one and the same animal repeatedly in the same dose, the proportion of the increase in the pulmonary lymph flow and protein concentration in the lymph was smaller after subsequent injections than after the initial injection. The proportion of increase in the femoral artery blood pressure was similarly diminished, and so was the proportion of the reduction in rate of respiration.IV. The effect of ligation the femoral veins bilaterally on the pulmonary lymph circulation under the influence of adrenaline.Methods and Results : Immediately after the intravenous injection of adrenaline, the femoral veins were ligated bilaterally with threads. Under this circumstance, the pulmonary lymph flow and protein concentration of the lymph showed no incr