• 한국수산과학회지
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• 제55권5호
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• pp.688-696
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• 2022

Obesity could cause immune-physiological disorders in fish. Yet, little is known about the impact of obesity on stress and histological responses. This study aimed to determine histological and physiological changes in and vulnerability of overfeeding-induced obese rainbow trout Oncorhynchus mykiss exposed to stress condition. Control, intermediate and overfed groups were fed at 1.5, 2.5 and 3.09% of their body weight per day, respectively, for eight weeks. Weight gain, body mass index, hepatosomatic index and serological parameters, and histology of liver were measured in five fish from each group at week 0, 2, 4, and 8. At week 8, 20 fish from each group were exposed to heat stress by increasing water temperature at a rate of 3℃ per day from 15 to 25℃ and maintaining the final temperature for 10 days. Overall, overfed fish showed significantly higher weight gain, body mass index, and serological parameters than those of fish in the other groups. Fish in the overfed and intermediate groups displayed multifocal infiltration of inflammatory cells in hepatic parenchyma. Mortality rate and serological parameters of fish in the overfed group exposed to heat stress were significantly higher than those of fish in the other groups, indicating increased vulnerability to environmental stress.

• Toxicological Research
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• 제17권3호
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• pp.187-194
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• 2001

The oxidative stress causes the cell damage and death and thereby, stimulates membrane lipid peroxidation. In this study, the correlation between the lipid peroxidation product and the parameter of liver fibrosis (cirrhosis) was investigated in cholestasis induced rats. The Sprague-Dawley rats were divided into 3 groups (sham: sham operation, BDL/S-I and BDL/S-II : bile duct ligation/scission) and were observed for 2 or 4 weeks. After observation period, the organs were weighed and the ratio of organ weight/body weight was calculated. Sera and liver tissue were used for the measurement of malondealdehyde (MDA), parameter of clinical biochemistry, total collagen content and the staining. The ratio of organ weight/body weight in BDL/S-I and BDL/S-II was significantly increased compared to sham operated group. Serological parameters (Alanine transaminase, Aspartate transaminase, Alkaline phosphatase and Total bilirubin) in BDL/S-I and BDL/S-II group were significantly higher than those in sham operated group. Concentration of MDA in BDL/S-I (261%) and BDL/S-II(790%) was significantly increased compared to MDA in sham operated group. And the content of hydroxyproline (hyp) in BDL/S-I and BDL/S-II group was significantly increased 2~4 times than in sham operated group. The good correlations between hyp in liver tissue and MDA in sera of sham operated group and all operated group were found (r=0.825). The significantly higher value of MDA, hyp and serological parameters in BDL/S-I and BDL/S-II group suggests the stimulation of lipid peroxidation and chronic liver damage. Especially the activation of lipid peroxidation and the stimulation of liver fibrosis was stronger in BDL/S-II group than in BDL/S-I group. The stronger fibrosis, portal-portal septum formation, the more massive bile duct proliferation in portal triads and stroma, and hepatocytes swelling were observed in liver tissue of and BDL/S-II group compared to BDL/S-I group. Conclusively, a good correlation between MDA as a lipid peroxidation marker and hyp as a liver fibrotic parameter could be connected with the process of liver fibrosis. Moreover, cholestasis condition may cause jaundice, activation of lipid peroxidation, and collagen accumulation in liver. Additionally, optimal observation period of bile duct obstruction for the screening of antioxidant and antifibrotic effect in rats would be four weeks.