Studies on protozoa. Part I. The metabolism of Leishman-Donovan bodies and flagellates of Leishmania Donovani

Abstract

1. A satisfactory homogeneous liquid culture medium for L. donovani is described, and the growth curve and accompanying pH changes in it are recorded. 2. The rates of oxygen and glucose uptakes of the flagellates decreased with the age of the cultures. Carbon dioxide was a product of metabolism, and during multiplication the respiratory quotient remained roughly constant. The parasites reduced methylene blue in vacuo, and the presence of —SH groups was demonstrated. Succinic acid was found to be the main metabolic product. 3. A method for the preparation of Leishman-Donovan bodies free from tissue, which still retained their infectivity, is described. 4. Their oxygen and glucose uptakes and respiratory quotient have been measured. 5. Addition of glucose to suspensions of washed parasites stimulated the oxygen uptakes of both flagellates and Leishman-Donovan bodies. Fructose, mannose and galactose were found to exert a similar effect upon the flagellates. 6. Cyanide, azide and iodoacetate inhibited the oxygen uptakes of both flagellates and Leishman-Donovan bodies to varying extents. 7. The action of several known leishmanicidal drugs on respiration of both forms of the parasite has been investigated.