The objective of this research was to characterize the adrenergic receptor response in veins of cattle that grazed tall fescue (Festuca arundinacea Schreb.), with (E+) and without (E-) fungal endophyte (Neotyphodium coenophialum) infection. Measurement of contractile response of lateral saphenous veins to selective adrenergic receptor agonists (alphal, phenylephrine; alpha2, BHT-920) revealed enhanced reactivity (greater contractile response) only for the alpha2 adrenergic receptor in E+ pastured cattle. This response was consistent over a 3-yr grazing period. Significant contractility differences in response to BHT-920 occurred at concentrations of 3x10(-6) M and greater. Early research has reasoned that the enhanced reactivity is due to endophyte toxin effect on intracellular signaling systems. The enhanced contractile effect would alter blood flow dynamics and contribute to clinical signs and pathologic change in animals. The alpha2-adrenergic receptor is also involved in the control of many metabolic reactions. Thus, for drug therapy to be successful in reversing the adverse effects of E+ tall fescue exposure in cattle, effects on the alpha2-adrenergic tissue receptors must be neutralized.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.2527/1998.76112853x | DOI Listing |
J Anim Sci
January 2025
Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40546, USA.
With the growing bourbon industry in the southeastern U.S. leading to increased production of liquid distillery byproducts, there is a pressing need to explore sustainable uses for whole stillage [containing residual grain (corn, rye, malted barley) and liquid after ethanol separation] in livestock nutrition.
View Article and Find Full Text PDFMicroPubl Biol
December 2024
Department of Crop and Soil Sciences, University of Georgia, Athens, GA, United States.
Tall fescue ( ) is a widely adopted forage and turf grass. This is partly due to a fungal endophyte, which confers both abiotic and biotic stress tolerance. Although PCR primers exist to test for endophyte presence, these were not designed to quantitatively analyze the amount of fungus in the plant.
View Article and Find Full Text PDFPlants (Basel)
November 2024
Xinjiang Uygur Autonomous Region Geology and Mineral Exploration and Development Bureau, Urumqi 830052, China.
The granite rubble soil produced through excavation during construction is nutrient-poor and has a simplified microbial community, making it difficult for plants to grow and increasing the challenges of ecological restoration. Recent studies have demonstrated that microbial inoculants significantly promote plant growth and are considered a potential factor influencing root development. Microorganisms influence root development either directly or indirectly, forming beneficial symbiotic relationships with plant roots.
View Article and Find Full Text PDFPhysiol Plant
December 2024
College of Grassland Agriculture, Northwest A&F University, Yangling, Shaanxi Province, P.R. China.
Hydrogen sulfide (HS) functions as a signaling molecule affecting plant growth, development, and stress adaptation. Tall fescue (Festuca arundinacea Schreb.), a bioenergy crop, encounters significant challenges in agricultural production owing to low light by shading.
View Article and Find Full Text PDFTransl Anim Sci
November 2024
Bayer Crop Science, St. Louis, MO, USA 63141-7843.
Winter wheat ( L.) is a significant forage source for livestock grazing in the Southern Great Plains (SGP). However, increasing input costs and changing climate conditions compel producers and researchers to search for alternative forage systems, such as cool-season perennials.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!