1971 Volume 24 Issue 3 Pages 130-140
Comparative observations were made on the acnte toxicity and effects on the circulatory system and smooth muscle caused by colistin salts such as colistin sulfate (C-S), colistin tartrate (C-T), colistin pantothenate (C-P) and other colistin derivatives such as sodium methanesulfonate (C-M).
The following results were obtained.
1. The LD50 in mice was 9.1mg/kg and 21.5mg/kg for C-S; 71.5, 11.5mg/kg and 43.0mg/kg for C-T; 15.7 and 75.0mg/kg for C-P; and 740 and 510mg/kg for C-M by intravenous and intraperitoneal injection, respectively.
2. On isolated cardiac muscle, all three colistin salts act facilitatively, while C-M acted paralytically.
The mechanisms of action were an excitation on the peripheral sympathetic nerve for the salts and a direct paralytic action on myocardium for C-M. The intensity of action by the salts was according to the order C-S>C-T>C-P.
3. Colistin salts exerted a contractile action on peripheral blood vessels and C-M dilatatory action.The intensity of the salts action followed the order C-S>C-T>C-P.
4. Colistin salts decreased on the isolated rabbit's intestinal movement and the mechanism of action was probably due to the cxcitation at the peripheral sympathetic nerve. C-M exerted a paralytic action on intestinal movement, probably directly on the smooth muscle in the intestinal wall. The intensity of action followed the order C-S>C-T>C-P.
5. Colistin salts and C-M exerted anti-histamine, anti-acetylcholine and anti-barium action. C-S was most intense, followed by C-T, then C-P, with C-M the least active.
