Location: Poisonous Plant Research
Project Number: 5428-32000-015-00
Start Date: Feb 11, 2008
End Date: Feb 10, 2013
Pyrrolizidine alkaloid (PA) metabolites (pyrrole) adducts such as pyrrole-thiamidine, pyrrole-guanine, pyrrole-methionine or pyrrole-glutathione will be linked to an immunogenic proteins and used as the immunogens to generate pyrrole specific antibodies. These same pyrrole-specific antibodies will be used to develop immunohistochemistry, ultrastructural immunochemistry and ELISA diagnostic techniques. Cellular kinetic will be documented and described. Additional biomarkers of poisoning will be developed using proteomic and genomic techniques. Tissue bound pyrroles or adducts that are likely to contaminate animal products, will be tested in mouse models for toxicity and carcinogenicity. The molecular events of hepatic carcinogenesis including altered expression or activation of various oncogenes, tumor suppressor genes and cell proliferation mediators will be evaluated. Similar sensitive mouse models will be used to test the fetal and neonatal effects of individual PA-toxicity. PA’s likely to cross the placenta or to be excreted in milk will be identified and the risk of such poisoning described. The toxicity of specific PA’s will be compared with PA chemical structure to identify those functional groups that are likely to lead to transplacental and transmammary transfer and poisoning. As rodent placentation is unique, these results (transmammary and transplacental PA transfer) will be verified in livestock. Rayless goldenrod and white snakeroot poisoning will be characterized by exposing horses to varying plant doses. The clinical, physiologic and pathologic response to poisoning will be monitored daily using clinical evaluations, exercise tolerance via treadmill evaluation of physical strength and endurance, electrocardiograms, echocardiography, hematology and serum biochemistry. The progression and lesions of poisoning will be described using biopsy, post mortem examination, histologic and ultrastructural evaluations. A dose response study using pregnant mares will be used to characterize fetal and neonatal poisoning and to identify which lesions are reversible. Photosensitization will be studied using clinical surveys. Clinical findings, histologic changes and hepatic function data will be collected, characterized and correlated with the serum and dermal phylloerythrin concentrations. Risk models of feed-related photosensitivity will be developed to predict susceptible populations and risk.