[Effect of high temperature on promastigotes of 2 species of Leishmania].

A morphological and chemical transformation of the protozoon Leishmania results during the shift from sand fly vector to mammalian host. This is due to the increase in temperature from about 26 degrees to about 35 degrees C. We evaluated the modifications induced by 37 degrees C on stationary phase promastigotes of two different Leishmania species (L. major and L. infantum). L. infantum changed to amastigote-like forms in a greater and quicker way than L. major; this fact could relate with the more elevated spreading capacity of this species in the human body.