Beta-adrenoblocking activity of a new derivative of 2-aminotetraline based on some metabolic responses in cats and rats.

Previous pharmacological investigations of a newly synthetized derivative of 2-aminotetraline: trans-2-isopropylamino-3-hydroxy-5,8-dimethoxy 1,2,3,4-tetrahydronaphthalene (3b) have shown it to possess a beta-adrenergic blocking activity. In the present work we studied the influence of 3b on some biochemical indices characteristic of beta-adrenergic stimulation: blood levels of glucose, lactate and FFA in cats and rats, and phosphorylase "a" activity in rat myocardium. The dose used (0.5 mg/kg) in rats was the same as the dose of propranolol (0.5 mg/kg). In all experiments on cats and rats compound 3b decreased the effects of isoproterenol on the blood levels of glucose, lactate and FFA and on the phosphorylase "a" activity of the myocardium and this action was comparable with that of propranolol. The similar molecular mass and LD50 of 3b and propranolol allowed quantitative comparisons of the beta-adrenoblocking effects of both drugs in the dose used. The results suggest that compound 3b possesses metabolic effects characteristic of beta-adrenoblocking agents.