Immunotoxicological evaluation of fish neutrophil exposed with chemical contaminations

2007 Fiscal Year Final Research Report Summary

• Project/Area Number: 17380116
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: General fisheries
• Research Institution: Tokyo University of Marine Science and Technology
• Principal Investigator: ENDO Makoto Tokyo University of Marine Science and Technology, Graduate School of Marine Science and Technology, Professor (80128355)
• Co-Investigator(Kenkyū-buntansha): MAITA Masashi Tokyo University of Marine Science and Technology, Graduate School of Marine Science and Technology, Professor (60238839) ; KATAGIRI Takayuki Tokyo University of Marine Science and Technology, Graduate School of Marine Science and Technology, Assistant Professor (50361811)
• Project Period (FY): 2005 – 2007
• Keywords: Pollution / Environment / Fisheries / Immunotoxicology

Research Abstract

(1) Neutrophil isolated from tilapia swim bladder was exposed with cadmium chloride for three hours and zymosan phagocytic activity and active oxygen of the neutrophil was measured. Mortality was monitored on challenged medaka and zebrafish with E. tarda after exposing to cadmium chloride (1x10^<-4> M). Tilapia neutrophil survival rates in the concentrations of cadmium chloride were 98% (0 M), 86% (1x10^<-4> M), 95% (1x10^<-5> M) and 96% (1x10^<-6> M). Dead cells frequently showed fragmented nuclei. Phagocytic activity was statistically lower in the group (1x10^<-4> M)and approximately 10% of active oxygen declined in all three exposed groups. No mortality rate was observed in medaka and zebra fish infected with E. tarda after the exposure to cadmium chloride.
(2) Juvenile fish (4 days after hatch) was exposed in two concentrations (a)waste water standard and (b)environmental standard of cadmium chloride and chromium(III) for 96 hours, then challenged with E. tarda to evaluate immunotoxicological effect of heavy metals. Fish exposed with the concentrations of the environmental standard (0.01 ppm) of cadmium chloride and waste water (2.0 ppm) and environmental standards (0.2 ppm) of chromium started dying at the same time range with control fish after challenged with E tarda. Gill epithelium cells in dead fish showed typical pycnosis and same degree of E. tarda cell numbers detecting with anti-E. tarda antibody staining.