Effect of propranolol and [4-(2-isopropylamino-1-hydroxyethyl) methanesulphonanilide hydrochloride] (MJ-1999) on pulmonary circulation.

While the pharmacological actions ofadrenergic beta receptor blocking agents specially those pertaining to cardiovascular system have been investigated in detail, there are only scattered reports dealing with their pulmonary vascular effects. Propranolol was shown to exert a variable effect on pulmonary arterial pressure and pulmonary vascular resistance (18). [4-( 2-isopropylamino-I-hydroxyethyl) methanesulphonanilide hydrochloride] (MJ-1999) wasfound to cause an increase in the calculated pulmonary vascular resistance (4). However, the direct effects of these drugs on the lung vessels independent of adrenergic beta receptor blockade have not been elucidated. Hence it was of interest to study their pulmonary vascular effects. Since cardiac and systemic vascular changes are known to modify the pulmonary vascular effects of drugs (2), the actions of propranolol and MJ-I999 on other circulatory parameters a nd their ability to alter the cardiopulmonary responses to adrenaline and isoprenaline were investigated.