Research Article

Researches on the Intestinal Protozoa of Monkeys and Man

III. The action of emetine on natural amoebic infections in Macaques

Clifford Dobella1 and Ann Bishopa1

a1 National Institute for Medical Research, London, N.W.3.

Five tame monkeys (3 Macacus sinicus and 2 M. rhesus) have been treated with emetine bismuthous iodide per os, in order to study the effects of the alkaloid upon their intestinal amoebae (and other protozoa).

These monkeys were originally infected with Entamoeba histolytica (large and small strains), Entamoeba coli, Endolimax nana, Enteromonas (= Tricercomonas), and Giardia. Treatment with emetine ultimately eradicated the E. histolytica infections from four out of five animals, but did not remove any of their other intestinal protozoa.

It has been found necessary to administer 60 mg. of emetine bismuthous iodide daily for about a week to a macaque weighing about 5 kg. in order to eradicate an infection with E. histolytica. Such dosage was toxic to four of the five monkeys used.

The general conclusion drawn is that emetine affects the various intestinal protozoa of M. sinicus and M. rhesus exactly as it does the comparable species in man; and it is suggested that macaques can therefore be utilized—if similar methods be employed—in place of men in future chemotherapeutic experiments directed towards the discovery of remedies for human amoebic dysentery.

(Received July 12 1929)