조피볼락, Sebastes schlegelii의 혈액학적 성상, 항산화 및 heat shock protein 70에 미치는 미세플라스틱의 영향

Abstract

With the increase in plastic production, a large amount of plastic waste has being discharged into the marine environment. Plastic waste break down into microplastics (MP) by various factors including ultraviolet rays, biodegradation, and photodegradation. The accumulation of MP in fish occur through respiration and ingestion, and consequently, it has toxic effects on physiological functions of fish. This study was aimed to evaluate the toxic effects of MP by measuring the bioaccumulation, hematological parameters, plasma components, antioxidant responses, cortisol, and heat shock protein 70 (HSP70) in Korean rockfish, Sebastes schlegelii exposed to waterborne MP. S. schlegelii (mean weight, 34.55 ± 5.82 g; mean length, 12.59 ± 0.79 cm) were exposed to MP at 0, 400, 800, 1600, and 3200 μg/L for 20 days. The accumulation of MP in intestine, gills, and liver significantly increased in proportional to MP concentration, and the pattern of them was in the order of intestine > gills > liver. Growth factors such as body weight gain (BWG) and specific growth rate (SGR) were significantly decreased at ≥ 1600 μg/L, whereas hepatosomatic index (HSI) was significantly increased. Hematological parameters such as the red blood cell (RBC) count and hemoglobin (Hb) were significantly decreased at ≥1600 μg/L. Plasma components such as glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and glucose increased at ≥1600 μg/L, whereas total protein, calcium, and magnesium were significantly decreased. In antioxidant responses, superoxide dismutase (SOD), catalase (CAT), and glutathione S-transferase (GST) in the intestine, gills, and liver were significantly increased at ≥1600 μg/L, whereas glutathione (GSH) was significantly decreased at 3200 μg/L. Cortisol and HSP70 in the intestine, gills, and liver were significantly increased at 3200 μ g/L and ≥1600 μg/L, respectively. The results of this study suggest that MP exposure can be accumulated in intestine, gills, and liver, and ≥1600 μg/L has toxic effects on physiological functions of fish.