System of 14C-glucose incorporation in axenic cultures of Entamoeba invadens: IP-1 strain.
BACKGROUND
It has been described that the walls of the amebic cysts from Entamoeba invadens are composed mainly of chitin, a polysaccharide of amino-sugars. It is also known that the synthesis of this polysaccharide is closely related to the degradation of the intracellular glycogen in this organism. Nevertheless, it is not known whether the intracellular glycogen is really the source of the glucose requirements for the synthesis of the cell wall.


METHODS
To determine the relationship between the wall cyst synthesis and glycogen degradation, it was considered to develop an in vitro culture cell system to label this polysaccharide with radioactive glucose. In this study, a system of 14C-glucose incorporation in axenic cultures of E. invadens was developed. The experiments in the study were carried out to recognize if an increase occurred in the 14C-glucose incorporation into ameba when the amount of the radioactivity used was increased, or whether this incorporation is a dependent metabolic stage.


RESULTS
The results showed that the amount of glucose incorporation reached similar values of 4.5 x 10(-12) mmol per cell in both cases. A different slope in the glucose kinetic incorporation between the cultures previously subjected to glucose depletion and the standard cultures was observed.


CONCLUSIONS
This axenic method of radioactive glucose incorporation in Entamoeba invadens could facilitate the analysis on a greater scale of the metabolism of this nutrient.
Centro de Investigación Biomédica del Noreste, Instituto Mexicano del Seguro Social, Monterrey, Nuevo León, Mexico.
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Calzado-Flores
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Segura
D000818:Animals; D002250:Carbon Radioisotopes; D002462:Cell Membrane / Q000378:metabolism; D004747:Entamoeba / Q000145:classification / Q000378:metabolism*; D005856:Germ-Free Life; D005947:Glucose / Q000378:metabolism*; D007553:Isotope Labeling / Q000379:methods*; D007700:Kinetics
D002250:Carbon Radioisotopes; D005947:Glucose