title: Effects of temperature on promastigotes of several species of Leishmania.
abstract: Six Leishmania species were studied comparatively, in order to determine the influence of temperature "in vitro" on differentiation, infectivity and protein synthesis. Differentiation occurred in a heterogeneous manner, even in species that produce similar clinical manifestations. Thus, no association could be found between thermosensitivity and disease. The association between expression of proteins and increasing temperatures was analyzed at 34 degrees C by polyacrylamide gel electrophoresis with sodium dodecyl sulphate (SDS-PAGE), using different incubation times, and employing a technique involving metabolic incorporation of [35S]-methionine. Protein synthesis was very similar in all the New World species apart from L. amazonensis, which expressed a protein of approximately 80 kDa when incubated at 34 degrees C for 2 hours. All the tested species had in common the expression of a 70 kDa protein. Differences, however, were observed in relation to the time interval for protein expression. In L. chagasi, synthesis was detected after 30 minutes of incubation at 34 degrees C, while L. braziliensis required 1 hour at the same temperature. The "in vivo" and "in vitro" infectivity of the differentiated forms was also analyzed, but no significant differences were observed.
mesh_terms: D000818:Animals; D006224:Cricetinae; D004591:Electrophoresis, Polyacrylamide Gel; D007891:Leishmania / Q000254:growth & development / Q000502:physiology*; D007896:Leishmaniasis / Q000503:physiopathology; D008715:Methionine / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008854:Microscopy, Electron; D015388:Organelles / Q000648:ultrastructure; D015800:Protozoan Proteins / Q000096:biosynthesis* / Q000302:isolation & purification; D013045:Species Specificity; D013462:Sulfur Radioisotopes; D013696:Temperature; D013997:Time Factors; D014774:Virulence
chemical_list: D015800:Protozoan Proteins; D013462:Sulfur Radioisotopes; D008715:Methionine