The organochlorine pesticide endosulfan has been shown to be highly toxic to fish
and there is some evidence to support that it may act as an endocrine disrupting chemical.
Juvenile rainbow trout (Oncorhynchus mykiss) were caged at 4 sites in Oshawa Creek
during the fall and spring of 2008 and 2009 while another group was intra-peritoneal
injected in the laboratory with varying concentrations (ppm) of endosulfan. Plasma
vitellogenin (VTG) levels, liver ethoxyresorufin-O-deethylase (EROD), citrate synthase
(CS), lactate dehydrogenase (LDH), and brain acetylcholine esterase (AChE) (caged fish
only) enzymatic activities were measured. Trout injected with endosulfan experienced an
increase of the anaerobic (LDH activity) and a decrease of the aerobic (CS activity)
metabolic pathways, while male VTG levels increased. Since it was a singular injection,
VTG results have to be confirmed. Fall caged trout showed increased EROD activity and
inhibited AChE activity while those caged in the spring experienced an unexpected
exposure to the lampricide 3-Trifluoro-Methyl-4-Nitro-Phenol (TFM) which disrupted
metabolic parameters (inhibited CS and increased LDH activity). Both fall and spring
caged trout experienced no induction of VTG activity. Further research is needed since
the spring exposure was altered due to the unplanned TFM treatment and thus did not
represent a valid temporal replicate.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OOSHDU.10155/30 |
| Date | 01 August 2009 |
| Creators | Armour, Jeffrey Andrew |
| Contributors | Holdway, Douglas, Bonetta, Dario |
| Publisher | UOIT |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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