title: Characterization of populations of promastigotes of Leishmania donovani.
abstract: Promastigotes of Leishmania donovani cultured for either 3 or 10 days in vitro and inoculated intracardially into golden hamsters with an equal number of organisms from either population showed a 7-fold difference in infectivity when compared at both 10 and 16 days post-infection. Reproducible histochemical staining for the promastigote enzymes glucose-6-phosphate dehydrogenase (G6PDH) and peptidase after polyacrylamide gel electrophoresis showed two isoelectric variants of G6PDH (Bands 1 and 2) that displayed a 45% decrease (Band 1) and a 60% increase (Band 2) in total activity when 3- and 10-day-old promastigotes were compared. Peptidase activity, present in a single band, increased 7-fold in 10-day-old promastigotes. A decrease in the lectin-induced agglutination of promastigotes by castor bean agglutinin (RCA60), specific for D-galactose and N-acetyl-D-galactosamine, was seen when 3- and 10-day-old promastigotes are compared. Antisera raised against sonicated 10-day-old promastigotes showed a unique precipitin band between the antiserum and sonicated 10-day-old promastigotes not found between the antiserum and sonicated 3-day-old promastigotes.
mesh_terms: D000116:Acetylgalactosamine / Q000032:analysis; D000818:Animals; D000941:Antigens / Q000032:analysis; D006224:Cricetinae; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D007527:Isoenzymes / Q000378:metabolism; D007891:Leishmania / Q000276:immunology / Q000502:physiology*; D007898:Leishmaniasis, Visceral / Q000469:parasitology*; D008099:Liver / Q000469:parasitology; D008297:Male; D008647:Mesocricetus; D010447:Peptide Hydrolases / Q000378:metabolism
chemical_list: D000941:Antigens; D007527:Isoenzymes; D005954:Glucosephosphate Dehydrogenase; D010447:Peptide Hydrolases; D000116:Acetylgalactosamine