Abstract

Bis-diethylenetriamine adducts (PG-DETA) have been synthesized from polypropylene glycols of various molecular weights. These compounds show pharmacological properties similar to those of curare. Neuromuscular blockade was produced with a dose of 1 mg/kg in the cat gastroenemius preparation and a concentration of 10^-5 g/ml in the isolated rat phrenic nerve-diaphragm preparation. These compounds produce a flaceid paralysis in chickens similar to that seen with curare. PG-DETA can be antagonized partially by appropriate doses of edrophonium, neostigmine or tetraethylammonium. PG-DETA abolishes the action potential in the muscle but the end-plate potential remains. Like curare PG-DETA is a weak ganglionic blocking agent and at 2 mg/kg it is capable of blocking the pressor effects of nicotine and/or splanchnic nerve stimulation. PG-DETA differs from curare in that it is more persistent in its action. The molecular weight of the glycol chain in these adducts influences the pharmacological activity; i.e., 400, moderate activity; 1200, high activity; and 2000, weak activity.