Publikationsdatenbank

Ex vivo application of Scrophularia extract and Monensin to determine their role on ruminal barrier function and nutrient uptake in sheep (2019)

Art

Vortrag

Autoren

Petri, Renee

Schrapers, Katharina (WE 2)

Sener-Aydemir, Arife

Aschenbach, Jörg (WE 2)

Zebeli, Qendrim

Kongress

International Symposium on Ruminant Physiology (ISRP 2019)

Leipzig, 03. – 06.09.2019

Quelle

Advances in Animal Biosciences

Bandzählung: 10

Heftzählung: 3

Seiten: 392

ISSN: 2040-4719

Sprache

Englisch

Verweise

URL (Volltext): https://www.cambridge.org/core/services/aop-cambridge-core/content/view/7D464B8882B4D5304683797665CD9E5E/S2040470019000037a.pdf/proceedings_of_the_xiiith_international_symposium_on_ruminant_physiology_isrp_2019.pdf

Kontakt

Institut für Veterinär-Physiologie

Oertzenweg 19 b
14163 Berlin
+49 30 838 62600
physiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Previous research has shown that extract from the Iranian plant Scrophularia striata had similar impacts on rumen fermentation and microbiota as monensin. The objective of this study was to determine the impact of both monensin and S. striata, specifically with regards to the acute (15 min) and chronic exposure (6 h) of the ruminal epithelia, on tissue permeability and nutrient uptake rates. Ovine ruminal epithelia from six female Merino landrace sheep were mounted in Ussing chambers under short-circuit conditions. The apical uptake of radioactively labelled 14C-acetate and 3H-propionate were measured as indicators of nutrient uptake transcellular absorption. The serosal-to-mucosal flux rate of fluorescein, an indicator of barrier function, was also measured over a 6-h period when tissues were subjected on their mucosal side to either a control treatment (ethanol (70% (v/v); CON), monensin (3μg/mL in ethanol; MON) or S. striata (600μg/mL in ethanol; SCRO). In addition, tissues were incubated with either a bicarbonate containing buffer (COF), a bicarbonate-free buffer (HEF) or a bicarbonate-free/nitrate-supplemented buffer (HEF-NO). The mucosal buffer solution had a pH of 6.1 and the serosal buffer pH 7.4. Tissue conductance (Gt) and short-circuit current (Isc) were monitored to assess epithelial integrity and active electrogenic ion transfer, respectively. The change of Isc (relative to baseline) tended to be highest for MON (P = 0.07) in the acute but not in the chronic phase of exposure. However, the Gt for MON was lower than CON and SCRO (P < 0.001) after 6-h exposure. There was a significant effect of buffer in the acute phase for Isc and Gt. However, only Gt was significant (P < 0.001) when corrected for baseline with the lowest tissue conductance measured in the HEF-NO buffer. There was no effect of supplementation on the apical uptakes of 14C-acetate and 3H-propionate. 3H-propionate had the highest total uptake at both the acute and chronic exposures and the bicarbonate-independent, nitrate-insensitive uptake (HEF – HEF-NO) also increased at 6 h for 3H-propionate but not for 14C-acetate. The fluorescein flux was significantly impacted by treatment throughout the 6 h measurement period with monensin maintaining a reduced flux (nmol/h/cm2) over time compared to both SCRO and CON (P < 0.001). These results indicate that monensin increases the epithelial integrity and the barrier function of ruminal epithelium under normal pH conditions, whereas luminal exposure to nitrate modulates the uptake of major nutrients across rumen epithelium.