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Trace metals in the viscera of Turbo marmoratus, a huge conical spire, in the coral reef of Ryukyu Island were analyzed. The highest amount of Zn and Fe was detectable in the midgut gland known to be polluted by saxitoxin. This intestine maintained a considerable amount of Si (higher than Ca) which fluctuated in parallel with the taurine amount. These data suggest that the viscera of the alimentary tract accumulate some metals, especially Zn and Fe. [ABSTRACT FROM AUTHOR]

Bacteria ingested by a neutrophil are located in phagosomes in which H2O2 is produced through the NADPH oxidase-dependent respiratory burst. Myeloperoxidase (MPO) plays important role in the bactericidal action of phagosomes. MPO catalyses the reaction of H2O2 and Cl- to produce HClO. The chemical mechanism behind the bactericidal action of the MPO–H2O2–Cl- system is unclear. Bactericidal action may result from (a) the direct reactions of HOCl with biological components (through amine chlorination) or (b) 1O2, formed non-enzymatically from HOCl and H2O2, that mainly works to kill microorganisms through bacterial respiratory chain injury. To answer this question, we developed a Cypridina luciferin analogue (MCLA)-dependent chemiluminescence method to determine the rate of formation of 1O2 from a 1O2 source at pH 4.5–9.0. Using the MCLA-dependent chemiluminescence method, we found that the rate of formation of 1O2 from the MPO–H2O2–Cl- system peaked at pH 7.0. Segal et al. (28) reported that almost all Staphylococcus aureus is killed 2 min after phagocytosis by neutophils where the phagosomal pH is 7.4–7.75. However, amine chlorination by HOCl did not proceed at pH > 7.0. Moreover, the bactericidal activities of the MPO–H2O2–Cl- system with Escherichia coli at pH 4.5 and 8.0 were paralleled by the rate of formation of 1O2. Combining these observations and the results reported by Segal et al., we concluded that 1O2 is a major chemical species in the killing of bacteria in neutrophil phagosomes. Copyright © 2003 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]