Author
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STABEL, THOMAS |
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Submitted to: American Journal of Veterinary Research
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/13/1998 Publication Date: N/A Citation: N/A Interpretive Summary: Salmonella is a group of enteric bacteria that cause swine diseases estimated to cost $100 million annually in the United States. Salmonella bacteria also are important human pathogens and are of great concern in food safety. The production and marketing of pigs present a number of stressful situations that can cause pigs to become more susceptible to infection with Salmonella. Thus, there is a need to understand the interaction between stress and Salmonella infection. We developed a new stress model using a sugar analog, 2-deoxy-D-glucose (2DG), to simulate physiological stress. Since 2DG had never been used in pigs, it was necessary to answer the most basic questions regarding route, dose, duration in the body, and ability to cause stress. The two best routes for 2DG delivery were intravenous and subcutaneous. If the intravenous route was used, the optimal dose was 500 mg 2DG/kg body weight. The optimal dose for subcutaneous injection was 750 mg 2DG/kg. This 2DG porcine stress model should be effective for studying the possible role of stress in exacerbating disease caused by Salmonella and other bacteria. Eventual beneficiaries of this model are the American consumer. Control of Salmonella will allow a continued supply of inexpensive, wholesome pork and pork products. Technical Abstract: Stress is a broad-based term which has been used to identify a range of situations which alter an animal's homeostasis. Central to the study of porcine stress and its effect on immunity has been the need for a well defined stress inducer capable of simulating a physiological stress response. A metabolic stressor in rodents, 2-deoxy-D-glucose (2DG) produces an acute intracellular glucoprivation with all the physiological hallmarks of a physical stressor. Prior to a complete study of the physiological effects of 2DG in pigs it was necessary to determine an appropriate route and dose for 2DG administration. Pigs were cannulated in the femoral artery to allow for frequent blood collection with minimal external stress. The concentration and duration of 2DG in the blood was monitored while varying dose (250, 500, or 750 mg/kg body weight) and route (intravenous [IV], subcutaneous [SC], intramuscular [IM], or intraperitoneal [IP]) of 2DG injection. The effects of 2DG on cortisol concentration and lymphocyte proliferation were also determined. Based on the above criteria, the two best routes for administration of 2DG were IV and SC. If the IV route was chosen the optimal dose was 500 mg 2DG/kg body weight. The optimal dose for SC administration was 750 mg 2DG/kg. 2-deoxy-D-glucose induced a stress response in pigs similar to that found in rodents. This 2DG porcine stress model should be effective for studying the possible role of stress in the pathogenesis and shedding of microorganisms. |
