Submitted to: International Symposium on Fungal Endophytes of Grasses
Publication Type: Abstract Only
Publication Acceptance Date: 6/2/2010
Publication Date: 6/28/2010
Citation: Strickland, J.R., Aiken, G.E., Klotz, J.L., Flythe, M.D., Brown, K.R. 2010. Ergot Alkaloids: Toxicokinetics and Vascular Effects in Grazing Animals. International Symposium on Fungal Endophytes of Grasses. pp 103-104.
Technical Abstract: Endophyte- (Neotyphodium coenophialum) infected tall fescue (Lolium arundinaceum) occupies nearly 14 million ha within the USA. Although the endophyte-forage association is beneficial to the plant’s survival and production, it is detrimental to grazing livestock as a consequence of ergot alkaloid production. Livestock consuming ergot alkaloid contaminated forage elicit a number of physiological responses including: elevated body temperatures, reduced growth and reproductive performance, abnormal hair growth and shedding, and altered hormonal profiles. Several of these responses may be explained by altered cardiovascular function. Ergot alkaloid induced alterations of cardiovascular function appear to be mediated via interactions with biogenic amine receptors. Understanding interactions of these alkaloids with biogenic amine receptors is vital to determining how pathogenesis is induced in livestock as well as full remediation of the resulting toxicity syndrome. Both in vitro (e.g., vascular bioassays) and in vivo (e.g., ultrasonography) methodologies have been useful in studying the effects these alkaloids. However, little research has been directed towards fully understanding the metabolism, distribution and clearance of these compounds. A lack of robust, selective and highly sensitive analytical methods for detection of these alkaloids and metabolites in animal tissues has limited research. Existing literature suggests metabolism of these alkaloids occur at several sites including: the ruminal environment, intestinal cells, and liver. Data suggest that these alkaloids are cleared from the body via urinary and fecal routes of elimination and that some bioaccumulation may occur. This review provides an overview of ergot alkaloid toxicokinetics, analysis and mechanisms of action with particular focus on the vascular systems of grazing livestock.