Journal of Animal Science, Vol 79, Issue 2 542-549, Copyright © 2001 by American Society of Animal Science

JOURNAL ARTICLE

Ergot alkaloid transport across ruminant gastric tissues

N. S. Hill, F. N. Thompson, J. A. Stuedemann, G. W. Rottinghaus, H. J. Ju, D. L. Dawe and E. E. Hiatt 3rd
Department of Crop and Soil Sciences, University of Georgia, Athens 30602, USA. nhill@uga.edu

Ergot alkaloids cause fescue toxicosis when livestock graze endophyte-infected tall fescue. It is generally accepted that ergovaline is the toxic component of endophyte-infected tall fescue, but there is no direct evidence to support this hypothesis. The objective of this study was to examine relative and potential transport of ergoline and ergopeptine alkaloids across isolated gastric tissues in vitro. Sheep ruminal and omasal tissues were surgically removed and placed in parabiotic chambers. Equimolar concentrations of lysergic acid, lysergol, ergonovine, ergotamine, and ergocryptine were added to a Kreb's Ringer phosphate (KRP) solution on the mucosal side of the tissue. Tissue was incubated in near-physiological conditions for 240 min. Samples were taken from KRP on the serosal side of the chambers at times 0, 30, 60, 120, 180, and 240 min and analyzed for ergot alkaloids by competitive ELISA. The serosal KRP remaining after incubation was freeze-dried and the alkaloid species quantified by HPLC. The area of ruminal and omasal tissues was measured and the potential transportable alkaloids calculated by multiplying the moles of transported alkaloids per square centimeter of each tissue type by the surface area of the tissue. Studies were conducted to compare alkaloid transport in reticular, ruminal, and omasal tissues and to determine whether transport was active or passive. Ruminal tissue had greater ergot alkaloid transport potential than omasal tissue (85 vs 60 mmol) because of a larger surface area. The ruminal posterior dorsal sac had the greatest potential for alkaloid transport, but the other ruminal tissues were not different from one another. Alkaloid transport was less among reticular tissues than among ruminal tissues. Transport of alkaloids seemed to be an active process. The alkaloids with greatest transport potential were lysergic acid and lysergol. Ergopeptine alkaloids tended to pass across omasal tissues in greater quantities than across ruminal tissues, but their transport was minimal compared to lysergic acid and lysergol.

This article has been cited by other articles:

				M. L. Merrill, D. W. Bohnert, D. L. Harmon, A. M. Craig, and F. N. Schrick The ability of a yeast-derived cell wall preparation to minimize the toxic effects of high-ergot alkaloid tall fescue straw in beef cattle J Anim Sci, October 1, 2007; 85(10): 2596 - 2605. [Abstract] [Full Text] [PDF]

				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 Anim Sci, September 1, 2007; 85(9): 2330 - 2336. [Abstract] [Full Text] [PDF]

				M. J. M. De Lorme, S. L. Lodge-Ivey, and A. M. Craig Physiological and digestive effects of Neotyphodium coenophialum-infected tall fescue fed to lambs J Anim Sci, May 1, 2007; 85(5): 1199 - 1206. [Abstract] [Full Text] [PDF]

				D. J. Fleetwood, B. Scott, G. A. Lane, A. Tanaka, and R. D. Johnson A Complex Ergovaline Gene Cluster in Epichloe Endophytes of Grasses Appl. Envir. Microbiol., April 15, 2007; 73(8): 2571 - 2579. [Abstract] [Full Text] [PDF]

				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 Anim Sci, November 1, 2006; 84(11): 3167 - 3175. [Abstract] [Full Text] [PDF]

				C. E. Realini, S. K. Duckett, N. S. Hill, C. S. Hoveland, B. G. Lyon, J. R. Sackmann, and M. H. Gillis Effect of endophyte type on carcass traits, meat quality, and fatty acid composition of beef cattle grazing tall fescue J Anim Sci, February 1, 2005; 83(2): 430 - 439. [Abstract] [Full Text] [PDF]

				R. Browning Jr. Effects of endophyte-infected tall fescue on indicators of thermal status and growth in Hereford and Senepol steers J Anim Sci, February 1, 2004; 82(2): 634 - 643. [Abstract] [Full Text] [PDF]