Research Summary

A current research project focuses on the detection of ergot alkaloids and any possible metabolites present in biological matrices (i.e. urine, serum, and feces) of forage animals, primarily horses and cattle.  The consumption of tall fescue containing ergot alkaloids by forage animals has been associated with certain disorders including low body weight, poor reproduction, as well as limb loss from decreased blood flow, resulting in livestock and overall economic loss for producers.  In the Bluegrass Region where the thoroughbred industry has significant economic weight, awareness of these disorders is important because ergot alkaloid toxicity within horses dramatically affects the reproductive cycle.  Although the ergot alkaloids have been previously extracted from various plant materials and determined to be the causative agents of toxicity, more research is necessary to identify possible metabolites resulting from exposure to biological systems to elucidate biochemical pathways that may be involved in the aforementioned symptoms. There are two primary goals of this research: I) to develop a diagnostic tool by directly measuring the amount of ergot alkaloids present in forage animals after ingestion of endophyte-infected forage and II) to detect intact alkaloids or the presence of any metabolite present after biotransformation.  The alkaloids and potential metabolites will serve as biomarkers for the detection of fescue toxicosis in the field.  Once detected, animals could be treated (one current chemical treatment is domperidone) to reduce the potential for clinical toxicity. The screening of biological matrices is a favored approach because one would directly know what the animal has ingested and to what extent.  In addition to a diagnostic tool, samples will be investigated to identify potential metabolites. Once metabolic processes affected by the ergot alkaloids have been identified and characterized, the development of specific target drugs and/or feeding regimens may be used to reduce incidences of severe tall fescue toxicosis and dramatically reduce the economic loss experienced by livestock producers. The investigations of ergot alkaloids with respect to tall fescue will be carried out with sample extractions and then subjected to further separation with reverse phase liquid chromatography (RP-LC).  The LC eluent will be directly coupled to a tandem mass spectrometer (MS/MS) using electrospray ionization to convert molecules to the gas phase for mass analysis.  Mass spectrometry is a powerful and sensitive analytical tool that can unambiguously identify a molecule with molecular weight information and fragmentation patterns that is not possible with absorption (UV-Vis) or emission (fluorescence) detection. The technique of LC-MS/MS has been well established and the use of this instrumentation for the presented problem is logical.

Dr. Smith is also interested in developing projects associated with the analysis of materials encountered in a forensic laboratory focusing on tandem mass spectrometry with chromatography inlets as well as ambient ionization sources. Improving existing methodologies or developing novel techniques in forensic laboratories is necessary to reduce cost, provide better accuracy, and quicken results.

Selected Publications

• J. L. Klotz, L. P. Bush, D. L. Smith, W. D. Shafer, L. L. Smith, B. C. Arrington, and J. R. Strickland, “Ergovaline-induced vasoconstriction in an isolated bovine lateral saphenous vein bioassay”, J. of Animal Science, 2007,85, 2330 - 2336
• J. L. Klotz, L. P. Bush, D. L. Smith, W. D. Shafer, L. L. Smith, A. C. Vevoda, A. M. Craig, B. C. Arrington, and J. R. Strickland, “Assessment of vasoconstrictive potential of D-lysergic acid using an isolated bovine lateral saphenous vein bioassay”, J. of Animal Science, 2006,84, 3167-3175
• L. L. Manza, S. G. Codreanu, S. L. Stamer, D. L. Smith, K. S. Wells, R. L. Roberts, D. C. Liebler, “Global Shifts in Protein Sumoylation in Response to Electrophile and Oxidative Stress”, Chem. Res. Toxicol., 2004, 17 (12), 1706-1715.
• D. M. Alloway, M. Hofmann, D.L. Smith, N.E. Gruhn, A.L. Grahm, R. Colorado, Jr., V.H. Wysocki, T.R. Lee, P.A. Lee, N.R. Armstrong, “Interface Dipoles Arising from Self-Assembled Monolayers on Gold: UV-Photoemission Studies of Alkanethiols and Partially Fluorinated Alkanethiols”, J. Phys. Chem. B, 2003, 107, (42), 11690-11699.
• D.L. Smith, R. Selvan, V.H. Wysocki, “Reactive Ion Scattering Spectrometry of Mixed Methyl- and Hydroxy-Terminated Alkanethiolate Self-Assembled Monolayers”, Langmuir, 2003, 19, 7302-7306.