TY - JOUR T1 - ON THE TOXIC ACTION OF OPIUM ALKALOIDS INDIVIDUALLY AND IN COMBINATION WITH EACH OTHER ON PARAMECIA JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 95 LP - 104 VL - 10 IS - 2 AU - DAVID I. MACHT AU - HOMER G. FISHER Y1 - 1917/08/01 UR - http://jpet.aspetjournals.org/content/10/2/95.abstract N2 - The results of the above investigation may be summarized as follows: 1. The morphin group of opium alkaloids is non-toxic or very little toxic to Paramecium putrinum. 2. The papaverin group of opium alkaloids is very toxic to the Paramecium putrinum. 3. Combinations of members of the morphin and papaverin groups produce a synergistic effect in respect to their toxicity for the Paramecium. 4. Combinations of members of the same groups of alkaloids show no synergism. 5. The toxic action of papaverin and its related alkaloids for the Paramecium is due to the benzyl grouping, present in their molecules. 6. Papaverin and dionin and to a lesser degree narcotin and narcein show a narcotic or anesthetic effect on paramecia distinct from their toxic action. ER -