Objective—To determine the usefulness of canine
RBC with high concentrations of potassium, reduced
glutathione (GSH), and amino acid(ie, HK cells) for in
vitro cultivation of Babesia gibsoni.
Animals—RBC were obtained from 3 dogs that had
inherited HK cells and from 3 genetically unaffected
dogs that, therefore, had RBC with lower potassium
(LK) concentrations (ie, LK cells).
Procedures—First, B gibsoni were cultivated using
HK or LK cells in alpha-modification of Eagle medium,
consisting of Earle salts with glutamine and without
ribosides, deoxyribosides, and sodium bicarbonate
under a humidified atmosphere containing 5% CO2 at
37 C. Second, parasites were cultivated with LK- or
HK-cell lysates. Finally, HK cells were separated into 3
fractions (bottom, middle, top layers) by density gradient
centrifugation, and B gibsoni were cultivated
with each of the HK-cell fractions. In addition, the concentrations
of free amino acids and reduced glutathione
(GSH) in each HK-cell fraction were measured.
Results—B gibsoni preferentially multiplied in HK-cell
cultures rather than in LK-cell cultures. Furthermore,
the addition of HK-cell lysate to the culture medium
resulted in enhanced multiplication of the parasites.
Higher multiplication of the parasites was observed in
HK cells from the top layer, compared with HK cells
from the middle and bottom layers. The HK cells from
the top layer had higher concentrations of glutamate,
aspartate, and GSH, compared with HK cells from the
middle and bottom layer.
Conclusions—Canine HK cells are useful host cells
for in vitro cultivation of B gibsoni, and the high concentrations
of glutamate, aspartate, and GSH may
result in enhancement of multiplication of the parasites
in HK cells. (Am J Vet Res 2000;61:1520–1524)