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Vol. 42 No. 3, 2003
Serum Metabolic Enzyme Activities and Hepatocyte
Ultrastructure of Common Carp after Gallium Exposure
Jen-Lee
Yang1,2 and Hon-Cheng Chen1,*
1Institute
of Zoology, National Taiwan University, Taipei, Taiwan 106
2Environment Protection Division, Ministry of
Education, Executive Yuan, Taipei, Taiwan 100
Jen-Lee
Yang and Hon-Cheng Chen (2003) Gallium (Ga) is one of the
intermetallic elements increasingly being used in making high-speed
semiconductors such as gallium arsenide. The purposes of this study
were to investigate the effects of gallium on serum enzyme activities
and on the ultrastructure of the liver in common carp (Cyprinus carpio). Common carp were
exposed to 3 different sublethal levels of gallium (2.0, 4.0, and 8.0
mg/l) in laboratory toxicity tests. During a 28-d testing period, serum
metabolic enzyme activity of aspartate aminotransferase (AST), alanine
aminotransferase (ALT), and alkaline phosphatase (ALP) was analyzed
every 14 d. An increase of enzyme activity in serum was observed,
particularly at the 2 highest exposure concentrations. Electron
microscopy investigations revealed ultrastructural alterations in
hepatocytes which were correlated with exposure concentrations and
exposure time. Cytopathological effects included nuclei with irregular
outlines and heterochromatin, fragmentation and vesiculation of
endoplasmic reticula, and disruption of mitochondria. Moreover,
proliferation of lysosomes with electron-dense bodies and lipid
inclusions were also found in the cytoplasm of hepatocytes. Our results
indicate that changes in metabolic enzyme activities in serum occurred;
this fact was confirmed by ultrastructural observations during the
exposure period. This study also emphasizes the importance of in vivo
approaches to the assessment of relative compound effects and their
potential hazards in aquatic animals.
Key words: Gallium,
Common carp, Metabolic enzyme, Hepatocyte.
*Correspondence: Tel: 886-2-23630231 ext. 3324. Fax:
886-2-23636837. E-mail: honcheng@ccms.ntu.edu.tw
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