碩士 / 國立嘉義大學 / 水生生物科學系研究所 / 97 / The aim of this study was to determine the energy metabolism of tilapia (Oreochromis mossambicus) upon acute cadmium (5 mg/L Cd) exposure. Various physiological indicators were measured after 0 h, 0.25 h, 0.75 h, 1 h, 3 h, 6 h, and 12 h of Cd exposure, including glycogen phosphorylase (GP) activity, glycogen content in the gills and liver, plasma cortisol levels, cations, glucose and lactose levels of blood. Results showed that the blood glucose was significantly increased and lactose levels no change at 1-12 h after acute Cd exposure. Gill GP activity increased immediately at 0.75 h-3 h but eventually recovered to the normal level at 6 h post-exposure in relation to the control group. Hepatic-GP activity was up-regulated at 1h-6h post-transfer to 5 mg/L Cd. GP mRNA expression significantly increase in gills at 3h while it was observed later at 6h in the liver. Glycogen content in the gills and liver were significantly depleted after acute Cd exposure, but the depletion occurred earlier in gills at 0.75 h than in the liver at 3h. In addition, ions such as Cl- , Na+, Ca2+ were significantly decreased while K+ was significantly increased. The cortisol content increased at 0.25 h-1 h post Cd-exposure. The glucagon mRNA expression in the intestines has no significant difference with that of the control group. Using real-time PCR, the glucocorticoid receptor mRNA expression in tilapia gills decreased at 0.75 h, while in the liver it significantly increased at 6 h post Cd-exposure as compared to the control group. In conclusion, the gill GP activity may be initially stimulated to provide prompt energy after Cd stress. Several hours later, the liver GP activity begins to increase for the subsequent energy supply. In the gills and liver, cortisol seems to be related to glycogen metabolism.
| Identifer | oai:union.ndltd.org:TW/097NCYU5061009 |
| Date | January 2009 |
| Creators | Yu-Siang Lin, 林昱翔 |
| Contributors | Su-Mei Wu, 吳淑美 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 65 |
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