Effects Of Individual And Multiplex Pollutants On Antioxidant Defense Enzyme In Aquatic Creature

Naphthalene and cadmium are two kinds of important chemical pollutants in ocean and are quite harmful to both human beings and aquatic plants and animals.Studies on toxicity and biological effect mechanisms of these two pollutants are hotspots in recent years.In this paper,the following studies were carried out:(1) Ulva(Ulva pertusa) were exposed to four concentrations(50mg/L,100mg/L, 150mg/L and 200mg/L) of individual and joint naphthalene and cadmium for 7 days in lab condition.Relative growth rate,chlorophyll content and activities of antioxidant defense enzyme(superoxide dismutase and catalase) in ulva exposed were measured and calculated,respectively.(2) Zebrafish(Danio rerio) were exposed to 1/4 LC₅₀ concentration of individual and joint naphthalene and cadmium for 15 days in lab condition.Activities of superoxide dismutase and catalase in zebrafish exposed were measured and calculated, respectively.(3) Lab-cultured ulva were exposed to real pollution areas near Dalian seashore for 1,3,5 and 14 days.Three types of pollution(industry,mariculture and living) areas and one relative clean area were carefully chosen for the comparisons with lab condition. Relative growth rate,chlorophyll content and activities of superoxide dismutase and catalase in ulva exposed to above areas at different time were measured and calculated, respectively.Results were further used for pollution assessment of the chosen areas near Dalian seashore.In lab condition,varieties of decreasing were obtained in growth,chlorophyll content,activities of superoxide dismutase and catalase in ulva exposed to high-concentration and short-period of naphthalene and cadmium,both individual and joint. Same trends of decreasing of superoxide dismutase and catalase activities were obtained from zebrafish exposed to 1/4 LCs0 concentration of individual and joint naphthalene and cadmium for 15 days. In real polluted condition,no significant change was obtained in relative growth rate and chlorophyll content from ulva exposed for short period(1-3days),while obvious decrease were observed from ulva exposed for relative long period(7-14days). Antioxidant Defense Enzymes activities were stimulated higher in short-period exposure and decreased along with exposure period.Relative growth rate,chlorophyll content,activities of superoxide dismutase and catalase all significantly decreased in industry pollution area,which demonstrated the industry area in Dalian seashore maybe worse polluted than mariculture and living areas.On the basis of published individual toxicity of naphthalene and cadmium,joint toxicity of these two pollutants was studied for the first time in this paper.From academic point of view,results obtained in this paper would provide basic research for joint toxicity study on naphthalene and cadmium.Additionally,the method establish in this paper for pollution assessment by molecular bio-indicator analysis of lab-cultured material exposed to real environment is quite sensitive and feasible.Therefore,this established method would be used for further study on multiplex pollution of real situation.