The action of isoproterenol on phenylthiourea induced pulmonary edema

Isoproterenol inhalation increases the pulmonary edema induced in rats by phenylthiourea. Propranolol decreases this response while phenoxybenzamine has no effect upon it. It is proposed that the observed increase in toxicity is related to the beta-adrenergic effects of the isoproterenol and that the specific mechanism responsible might be an increase in pulmonary capillary hydrostatic pressure which is secondary to an increase in pulmonary blood flow.