[The effect of nitric oxide donor on the DNA content in Toxoplasma gondii tachyzoite].
OBJECTIVE
To determine the role of sodium nitroprusside (SNP) in regulating DNA synthesis of Toxoplasma gondii tachyzoites.


METHODS
Hypodiploid peak of tachyzoite DNA induced by SNP was assessed according to DNA fragmentation. The effect of SNP on appearance of hypodiploid peak and the effect of Ca2+ on the growth of tachyzoites were evaluated. The intracellular Ca2+ chelator (BAPTA/AM), antagonist of Ca2+ channel (verapamil) and the extracellular Ca2+ chelator (EGTA) were used. The change of DNA content was measured by flow cytometry.


RESULTS
SNP inhibited DNA synthesis of tachyzoites in a dose- and time-dependent pattern. The antiproliferative effect of SNP on tachyzoites was inhibited by verapamil, EGTA and BAPTA/AM. The inhibition of the growth of tachyzoites by SNP was associated with increased subploid peak through a Ca(2+)-dependent mechanism.


CONCLUSIONS
SNP induced a hypodiploid peak in tachyzoites by altering the Ca2+ concentration in the plasma of tachyzoite, resulting in damages of the parasite.
Peng
B W
BW
Department of Molecular Medicine, Fujian Medical University, Fuzhou 350004.
Hu
J S
JS
Zhao
R
R
Jiang
M S
MS
Lin
J Y
JY
D000818:Animals; D002118:Calcium / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D016054:DNA, Protozoan / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009599:Nitroprusside / Q000494:pharmacology*; D014122:Toxoplasma / Q000187:drug effects* / Q000378:metabolism
D016054:DNA, Protozoan; D020030:Nitric Oxide Donors; D009599:Nitroprusside; D002118:Calcium