Libro de Resúmenes / Book of Abstracts (Español/English)

Resumenes 156
The present investigation examines the relationship between the population
density and the morphological stage of L. chagasi presents in vitro with the
changes in concentration of trophic substrates in the culture medium.
In such a way, promastigotes (5×10 4 /ml) were seeded in screw cap plastic
flasks (500 ml) containing 150 ml of BHI culture medium. A day after the
sowing of the parasites, and every other day until the death of the
organisms, one ml of culture medium supernatant was picked up in order to
determine the population density, the diversity of stages (promastigote,
sphaeromastigote and micromastigote), as well as the concentrations of
albumin, cholesterol, glucose, total proteins and triglycerides.
Each substrate showed a particular velocity of consumption. Using the
graphic representation of every treatment in function of the population
Y 2 − Y1
density, we calculated the velocity from V = , where “y” represents
X 2 − X 1
the treatment and “x” the population density. Likewise, we estimated an
approximation to the replication percentage vs. death percentage expressed
200
as y= Arctg(x) . Eloquent differences were found among treatments in
π
relation to the changes of shape.
Keywords: Leishmania chagasi, velocity of consumption, trophic behavior.