Localization of superoxide anion in the red tide alga Chattonella antiqua.

Abstract

To investigate the localization of superoxide anion generated in the red tide alga Chattonella antiqua, we added to the incubation medium 3,7-dihydro-6-[4-(2-(N'-(5-fluoresceinyl)thioureido) ethoxy)phenyl]-2-methylimidazo(1,2-a)pyrazin-3-one (FCLA), which is a Cypridina luciferin analogue and a specific fluorescent probe for detecting O2- and 1O2. The live phytoplankter was observed with the laser scanning microscope. At high magnification (x 6400) it was found that the plankter has many large and small verruciform protrusions on the cell surface. When the cell was irradiated with an argon laser (488 nm), a very intense fluorescence was noted at each protrusion. This fluorescence was completely inhibited by the addition of superoxide dismutase to the incubation medium, thus suggesting O2- generation at each verruciform protrusion on the cell surface.

Antioxidant responses and lipid peroxidation in gills and erythrocytes of fish (Rhabdosarga sarba) upon exposure to Chattonella marina and hydrogen peroxide: Implications on the cause of fish kills

“…Several studies postulated that ROS produced by C. marina were the principal ichthyotoxic agent (Shimada et al, 1991(Shimada et al, , 1993Oda et al, 1992aOda et al, , 1992bOda et al, , 1994Oda et al, , 1995Oda et al, , 1997Tanaka et al,. , 1994Tanaka & Muto, 1992;Kim et al, 2000).…”

“…(Shimada et al, 1991(Shimada et al, , 1993Oda et al, 1992aOda et al, , 1992bOda et al, , 1994Oda et al, , 1995Oda et al, , 1997Kim et al, 1999a). No conclusive scientific evidence is, however, available to prove any of these inferences.…”

“…All raphidophytes are known to produce ROS (Tanaka et al, , 1994Tanaka & Muto, 1992;Shimada et al, 1993;Oda et al, 1992aOda et al, , 1992bOda et al, , 1994Oda et al, , 1995Oda et al, , 1997Kim et al, 1999b), including superoxide (O 2 .-), hydrogen peroxide (H 2 O 2 ) and hydroxyl radicals (OH . ).…”

“…The fact that raphidophytes can produce ROS per se however, does not necessarily mean that ROS is the cause of fish kills, since the levels of ROS during Chattonella blooms and fish kills are unknown, and it has not been demonstrated that the levels of ROS produced are sufficiently high to kill fish. Shimada et al (1993) Furthermore, the glycocalyx may stick to the gill surface, resulting in continuous O 2 .-generation and hence severely damage gill tissue (Kim et al, 2001). There is, however, no direct evidence to demonstrate whether the level of ROS induced by fish mucus is sufficient to cause oxidative stress, gill damage or fish mortality.…”

Localization of tumor by chemiluminescence probe during photosensitization action

“…FCLA recently developed by Goto and co-workers, is a Cypridinaluciferin analogue and is characterized by emitting light at the longest wavelength (532 nm) among the CL substances known up to now [8][9][10]. Conventional photosensitized reactions of HpD were performed in vitro and in vivo.…”