Schistosoma mansoni: use of a fluorescent indicator to detect nitric oxide and related species in living parasites.
Nitric oxide (NO) is synthesized enzymatically by nitric oxide synthase (NOS). Several groups have previously presented evidence for NOS activity and immunoreactivity in several parasitic platyhelminths, including schistosomes. Here, we use 4,5-diaminofluorescein-2 diacetate (DAF-2 DA), a fluorescent indicator of NO, to detect NO in living schistosomes. In adult worms, DAF-2 fluorescence is found selectively in epithelial-like cells. Fluorescence increases when worms are incubated in L-arginine, the precursor of NO synthesis, and decreases dramatically in the presence of the NOS inhibitor N(G)-nitro-L-arginine methyl ester, indicating that predicted NO release may be NOS-dependent, and that enzymatic NO signaling pathways may play an important role in schistosome physiology.
Kohn
Andrea B
AB
Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, 32080, USA.
Lea
Jeanne M
JM
Moroz
Leonid L
LL
Greenberg
Robert M
RM
D000818:Animals; D001120:Arginine / Q000378:metabolism; D005260:Female; D019793:Fluorescein; D005456:Fluorescent Dyes; D008297:Male; D051379:Mice; D008856:Microscopy, Fluorescence; D019331:NG-Nitroarginine Methyl Ester / Q000378:metabolism / Q000494:pharmacology; D009569:Nitric Oxide / Q000032:analysis* / Q000096:biosynthesis; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D012550:Schistosoma mansoni / Q000737:chemistry* / Q000378:metabolism
C414689:4,5-diaminofluorescein diacetate; D005456:Fluorescent Dyes; D009569:Nitric Oxide; D001120:Arginine; D019001:Nitric Oxide Synthase; D019793:Fluorescein; D019331:NG-Nitroarginine Methyl Ester