Studies in microcataphoresis. II.—the electric charge of haemoflagellates

Abstract

1. 1. The electric charge in glucose-saline, pH 7·2, of the insect, cultural, and blood forms of a number of trypanosomes and other haemoflagellates have been examined. 2. 2. The insect and cultural forms have been found to be negatively charged. 3. 3. The blood forms may be positively or negatively charged. In some instances, both positively and negatively charged trypanosomes may be present in the blood of an infected animal simultaneously. 4. 4. No alteration in the sign of the charge takes place in continuous progressive infections during serial passage in mice for more than thirty generations. 5. 5. However, the sign of the charge of the trypanosomes which reappear after apparent spontaneous cure and subsequent relapse in mice is invariably the opposite of that carried by the original strain. 6. 6. Alteration of the host can also change the sign of the charge of trypanosomes. 7. 7. A simple “salt-concentration test” for determining the sign of the electric charge of trypanosomes is described. 8. 8. In the case of T. evansi it is shown that the “positive” variant is distinctly more susceptible to the action of tryparsamide than the “negative” one. 9. 9. “Positive” and “negative” variants also differ serologically. 10. 10. The importance of the electric charge in the chemotherapy and serology of trypanosomes is briefly discussed.