Exogenous Nitric Oxide Induces Apoptosis in Tachyzoites of Toxoplasma gondii / 中国寄生虫学与寄生虫病杂志

ABSTRACT

Objective To explore whether NO is able to induce apoptosis in Toxoplasma gondii tachyzoites.Methods Apoptosis induced by NO in T^gondii tachyzoites was investigated by TUNEL (terminal\|deoxynucleotidyl transferase mediated d\|UTP nick end labeling ) method, electron microscopy and agarose gel electrophoresis. Results NO donor, sodium nitroprusside (SNP),was found to induce apoptosis in Toxoplasma gondii tachyzoites in a time\| and dose\|dependent manner by TUNEL detection. N\|acetylcysteine, a NO scavenger, could inhibit SNP\|induced apoptosis in the tachyzoites while potassium ferricyanide could not induce apoptosis in the tachyzoite. Electron macroscopy showed that SNP\|treated tachyzoites possessed typical morphological features of apoptosis, including chromatin condensation below the nuclear membrane, nuclear pyknosis, and formation of apoptotic body.Agarose gel electrophoresis revealed that SNP\|treated tachyzoite DNA fragment exhibited characteristic "DNA ladder" after 15 to 20 h. Conclusion SNP, NO donor, might induce apoptosis in T^gondii tachyzoites in terms of characteristic morphological and biochemical features.