Subacute immunotoxic effects of the environmental contaminants 7,12-dimethylbenzanthracene (DMBA), hexachlorocyclohexane (lindane), and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on spleen and pronephros cellularity and morphology and functional activity of macrophages contained in these hematopoietic organs in the cichlid fish tilapia (<i>Oreochromis niloticus</i>)

Alterations of immune parameters were investigated in fish exposed to non-overtly toxic levels of three different environmentally relevant chemicals, 7,12-dimethylbenzanthracene (DMBA), hexachlorocyclohexane (lindane), and 2,3,7,8- tetrachlorodibenzo-p -dioxin (TCDD). Each chemical agent was administered to tilapia in separate experiments by intraperitoneal injection for five consecutive days. Following the final dose, total cellularity and histology of the spleen and pronephros were assessed, as were activity of phagocytic celis contained in these hematopoietic organs. <p>Using chemical doses which produced no clinical toxicity, tilapia exposed to each chemical agent displayed a significant reduction in total cell number of both spleen and pronephros, in most cases in a dose-related manner. Consistent with this observation, splenic and pronephric hypocellularity was confirmed upon histological examination of chemical-treated fish. However, neither superoxide radical production or phagocytosis of splenic or pronephric macrophages was inhibited in either DMBA, lindane, or TCDD exposed fish. Results of this study indicate that depressed total cell number in fish hematopoietic organs may be a more sensitive indicator of exposure to these environmental contaminants than is the activity of macrophages contained within these organs.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Veterinary Medical Sciences

Department dc:contributor.department

Veterinary Medical Sciences

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

1996

Author dc:creator

• Hart, Laura J.

Chair dc:contributor.committeechair

• Holladay, Steven D.

Committee members dc:contributor.committeemember

• Smith, Bonnie J.
• Smith, Stephen A.
• Nagarkatti, Mitzi

• flow cytometry
• histology
• immunosuppression
• fish hematopoietic organs
• macrophage

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

etd-09182008-063320

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/44809