Format

Send to

Choose Destination
Proc Natl Acad Sci U S A. 1998 May 12;95(10):5700-5.

The mosquito Anopheles stephensi limits malaria parasite development with inducible synthesis of nitric oxide.

Author information

1
Department of Entomology, Walter Reed Army Institute of Research, Washington, DC 20307, USA.

Abstract

We have discovered that the mosquito Anopheles stephensi, a natural vector of human malaria, limits parasite development with inducible synthesis of nitric oxide (NO). Elevated expression of A. stephensi NO synthase (NOS), which is highly homologous to characterized NOS genes, was detected in the midgut and carcass soon after invasion of the midgut by Plasmodium. Early induction is likely primed by bacterial growth in the blood meal. Later increases in A. stephensi NOS expression and enzyme activity occurred at the beginning of sporozoite release. Circulating levels of nitrite/nitrate, end-products of NO synthesis, were significantly higher in Plasmodium-infected mosquitoes. Dietary provision of the NOS substrate L-arginine reduced Plasmodium infections in A. stephensi. In contrast, dietary provision of a NOS inhibitor significantly increased parasite numbers in infected mosquitoes, confirming that A. stephensi limits Plasmodium development with NO.

PMID:
9576947
PMCID:
PMC20442
DOI:
10.1073/pnas.95.10.5700
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center