Transcript Slide 1
Background • Man made chemicals are everywhere – in virtually all living creatures and environments • Synthetic chemicals can mimic natural hormones upsetting normal reproductive and developmental processes • Immunosuppression has also been linked to organic pollutants • If pollution loads can act as endocrine disruptors and depress immunity, individuals may experience lowered survivability. Background- Cont. While contaminants occur in low levels in many animals, due to the persistant nature of the compounds, body burdens increase with an increase in trophic level. OBJECTIVE: • To look at the body burden of organochlorine and heavy metals compared to thyroid function (including retinol) and immunoglobulin values The Function of Thyroid and Retinol Hormones • Hormones represent an integrated response to a number of environmental and physiological factors that influence reproduction, growth, metabolism, and body condition. • Thyroid hormones are involved in the regulation of energy management in mammals through changes in basal metabolic rate, the absorption of carbohydrates from the intestine, lipid metabolism, and heat production. Retinoic acid (vitamin A) must be present for protein synthesis to occur. Low levels contribute to decreased ability to make antibodies. DDT Single Hormone Action EXTERNAL PERTURBATIONS Environmental Change Disease Change in Food Abundance/Quality Increased Predators Contaminants PHOTOPERIOD/SEASON STRESS HYPOTHALAMUS Releasing Hormones PITUITARY Innervation Other Factors TROPIC HORMONES TSH GnRH ACTH THYROID GONAD IMMUNE SYTEM ADRENAL ADRENAL HORMONES GONADAL STEROIDS THYROXINE METABOLIC HOMEOSTASIS Growth, Reproduction THYMUS MARROW LYMPHOCYTES IgG Crosses placenta (in some species) Important in primary and secondary immune response Most prevalent immunoglobulin in serum IgM Activation of B cell Important in primary immune response Most important immunoglobulin in agglutinating bacteria in serum IgA Most prevalent immunoglobulin in mucosal areas of the body (e.g. milk, saliva, tears) Most important immuoglobulin in removing bacteria from mucosal areas IgD No known function, except activation of B cell IgE Involved in allergic responses Involved in response to parasites Determination of Immunoglobulin Levels . Monoclonal antibodies against Steller sea lion immunoglobulins are used in the development of an ELISA that will allow us to monitor immunoglobulin levels in serum samples. Reagents can be used: 1) To determine the immunocompetence of an animal. 2) To determine specific immunoglobulin titers for specific pathogens within captive or wild Steller sea lions. 3) As a tool in for monitoring the immunological health of these animals Methodology for OC Evaluation Two methods used to investigate OC loads: I. HPLC/PDA (high-performance liquid chromatography with photodiode array detection) this method was developed to rapidly measure toxic “dioxin-like” CBs and congeners. It is less expensive and less time consuming but has higher LODs (levels of detection) II. HRGC/ECD (high-resolution gas chromatography with electron capture detector) this method is approximately 1000x more sensitive but involves longer sample prep and less cost effective. Sample Justification Goal is to obtain Steller sea lion samples from geographic range and all age groups. Most of the North Pacific basin is represented. Samples will be tested for immunocompetence, OC loads, and hormones Multivariate analysis performed to determine relationships, spatial and temporal trends Acknowledgements We would like to thank the Russian Federation, NMFS, ADF&G, the Universities of Hawaii, Alaska (Fairbanks), Southern Mississippi and the many graduate students and interns that have helped this project continue to grow and prosper.