Role of nitric oxide and superoxide in Giardia lamblia killing
Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO) donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine). Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites). This effect was inhib...
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Associação Brasileira de Divulgação Científica
1997-01-01
|
| Series: | Brazilian Journal of Medical and Biological Research |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000100015 |
| _version_ | 1818254373577293824 |
|---|---|
| author | P.D. Fernandes J. Assreuy |
| author_facet | P.D. Fernandes J. Assreuy |
| author_sort | P.D. Fernandes |
| collection | DOAJ |
| description | Giardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO) donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine). Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites). This effect was inhibited (>90%) by an NO synthase inhibitor (200 µM) and unaffected by superoxide dismutase (SOD, 300 U/ml). Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP) and sodium nitroprusside (SNP) in a dose-dependent manner (LD50 300 and 50 µM, respectively). A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1), did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml) was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35% dead trophozoites at 1 mM). The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM). These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitrite |
| first_indexed | 2024-12-12T16:54:56Z |
| format | Article |
| id | doaj.art-74cc5c77bb69455ba1d1c62b554f15b1 |
| institution | Directory Open Access Journal |
| issn | 0100-879X 1414-431X |
| language | English |
| last_indexed | 2024-12-12T16:54:56Z |
| publishDate | 1997-01-01 |
| publisher | Associação Brasileira de Divulgação Científica |
| record_format | Article |
| series | Brazilian Journal of Medical and Biological Research |
| spelling | doaj.art-74cc5c77bb69455ba1d1c62b554f15b12022-12-22T00:18:15ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X1414-431X1997-01-013019310.1590/S0100-879X1997000100015Role of nitric oxide and superoxide in Giardia lamblia killingP.D. FernandesJ. AssreuyGiardia lamblia trophozoites were incubated for 2 h with activated murine macrophages, nitric oxide (NO) donors or a superoxide anion generator (20 mU/ml xanthine oxidase plus 1 mM xanthine). Activated macrophages were cytotoxic to Giardia trophozoites (~60% dead trophozoites). This effect was inhibited (>90%) by an NO synthase inhibitor (200 µM) and unaffected by superoxide dismutase (SOD, 300 U/ml). Giardia trophozoites were killed by the NO donors, S-nitroso-acetyl-penicillamine (SNAP) and sodium nitroprusside (SNP) in a dose-dependent manner (LD50 300 and 50 µM, respectively). A dual NO-superoxide anion donor, 3-morpholino-sydnonimine hydrochloride (SIN-1), did not have a killing effect in concentrations up to 1 mM. However, when SOD (300 U/ml) was added simultaneously with SIN-1 to Giardia, a significant trophozoite-killing effect was observed (~35% dead trophozoites at 1 mM). The mixture of SNAP or SNP with superoxide anion, which yields peroxynitrite, abolished the trophozoite killing induced by NO donors. Authentic peroxynitrite only killed trophozoites at very high concentrations (3 mM). These results indicate that NO accounts for Giardia trophozoite killing and this effect is not mediated by peroxynitritehttp://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000100015nitric oxidemacrophageperoxynitriteGiardia lambliacytotoxicitysuperoxide |
| spellingShingle | P.D. Fernandes J. Assreuy Role of nitric oxide and superoxide in Giardia lamblia killing Brazilian Journal of Medical and Biological Research nitric oxide macrophage peroxynitrite Giardia lamblia cytotoxicity superoxide |
| title | Role of nitric oxide and superoxide in Giardia lamblia killing |
| title_full | Role of nitric oxide and superoxide in Giardia lamblia killing |
| title_fullStr | Role of nitric oxide and superoxide in Giardia lamblia killing |
| title_full_unstemmed | Role of nitric oxide and superoxide in Giardia lamblia killing |
| title_short | Role of nitric oxide and superoxide in Giardia lamblia killing |
| title_sort | role of nitric oxide and superoxide in giardia lamblia killing |
| topic | nitric oxide macrophage peroxynitrite Giardia lamblia cytotoxicity superoxide |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X1997000100015 |
| work_keys_str_mv | AT pdfernandes roleofnitricoxideandsuperoxideingiardialambliakilling AT jassreuy roleofnitricoxideandsuperoxideingiardialambliakilling |