Effects of seasonal changes in food quality and food intake on the transport of sodium and butyrate across ruminal epithelium of reindeer

Storeheier, P. V.; Sehested, Jakob; Diernæs, L; Sundset, Monica A.; Mathiesen, Svein D.

doi:10.1007/s00360-003-0345-9

Cited by 18 publications

(11 citation statements)

References 25 publications

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“…Conversely, electroneutral Na absorption is minimized by the removal of stimulatory anions such as Cl 2 , HCO 3 2 , and SCFA 2 (Chien and Stevens, 1972;Henseleit, 1991). Interestingly, in ruminants, the amount of Na 1 absorbed by the rumen in vitro shows a very robust correlation to the amount of SCFA absorbed, as has been shown in the rumen not just of sheep (Gä bel et al, 1991b), but also of cows (Sehested et al, 1993 and and reindeer (Storeheier et al, 2003). This suggests an important function of Na 1 as a counterion accompanying the absorption of SCFA 2 from the rumen.…”

Section: Electroneutral Namentioning

confidence: 71%

“…In net terms, this would correspond to an absorption of SCFA 2 and H 1 on a 1 : 1 basis. However, studies across the rumen epithelium in sheep, cows and reindeer show a very consistent coupling of SCFA transport with Na 1 transport (Danielli et al, 1945;Gä bel et al, 1991b;Sehested et al, 1993 andStoreheier et al, 2003), suggesting that Na 1 is the counterion for transepithelial transport of SCFA 2 and not H 1 . As outlined above, the major fraction of Na 1 is taken up electroneutrally via NHE and leaves electrogenically via the Na…”

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confidence: 98%

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Transport of cations and anions across forestomach epithelia: conclusions from in vitro studies

Leonhard-Marek

Stumpff

Martens

2010

Animal

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Secretion of saliva as well as absorptive and secretory processes across forestomach epithelia ensures an optimal environment for microbial digestion in the forestomachs. Daily salivary secretion of sodium (Na 1 ) exceeds the amount found in plasma by a factor of 2 to 3, while the secretion of bicarbonate (HCO 3 2 ) is 6 to 8 times higher than the amount of HCO 3 2 in the total extracellular space. This implies a need for efficient absorptive mechanisms across forestomach epithelia to allow for an early recycling. While Na 1 is absorbed from all forestomachs via Na 1 /H 1 exchange and a non-selective cation channel that shows increased conductance at low concentrations of Mg 21 , Ca 21 or H 1 in the luminal microclima and at low intracellular Mg 21 , HCO 3 2 is secreted by the rumen for the buffering of ingesta but absorbed by the omasum to prevent liberation of CO 2 in the abomasum. Fermentation provides short chain fatty acids and ammonia (NH 3 ) that have to be absorbed both to meet nutrient requirements and maintain ruminal homeostasis of pH and osmolarity. The rumen is an important location for the absorption of essential minerals such as Mg 21 from the diet. Other ions can be absorbed, if delivered in sufficient amounts (Ca 21 , P i , K 1 , Cl 2 and NH 4 1 ). Although the presence of transport mechanisms for these electrolytes has been described earlier, our knowledge about their nature, regulation and crosstalk has increased greatly in the last years. New transport pathways have recently been added to our picture of epithelial transport across rumen and omasum, including an apical non-selective cation conductance, a basolateral anion conductance, an apical H 1 -ATPase, differently expressed anion exchangers and monocarboxylate transporters.Keywords: ruminants, sodium potassium magnesium and calcium, short chain fatty acids, chloride and bicarbonate, channels transporters and exchangers ImplicationsThe improved knowledge of ruminal ion transport clearly underlines its physiological meaning for the whole animal. For example, magnesium absorption is markedly reduced at low Mg and high K intake and the effect of potassium is diminished at high Mg intake. This variable interaction has been quantified recently permitting the prediction of Mg absorption. Great progress has also been made in understanding the interactions between the absorptive pathways for Na, short chain fatty acids and ammonium. The new findings on structure and regulation of various ion transporters will allow a better understanding of the challenges that different diets pose to the maintenance of homeostatic conditions within the rumen and within the cells of the surrounding epithelium, with the implications for the investigation of ruminal adaptation to different diets. Future studies on transport pathways should include the barrier function of rumen epithelium and its possible impairment under harsh feeding conditions.

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Section: Electroneutral Namentioning

confidence: 71%

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confidence: 98%

Transport of cations and anions across forestomach epithelia: conclusions from in vitro studies

Leonhard-Marek

Stumpff

Martens

2010

Animal

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“…Higher transport rates are thought to result from well-described morphological transformations (Dirksen et al, 1984) leading to a size increase in the rumen epithelium papillae and consequently to an enlargement of the available absorptive surface area (Liebich et al, 1987;Shen et al, 2004). In addition, early functional adaptation processes involving the altered activity and/or expression of cellular transport proteins have been described (Storeheier et al, 2003;Uppal et al, 2003;Shen et al, 2004;Etschmann et al, 2009). In accordance with a specific role for active transport proteins in rumen epithelial adaptation, a significant enhancement of Na + /K + -ATPase activity by concentrate feeding has been found (Kristensen et al, 1995;McLeod and Baldwin, 2000).…”

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confidence: 99%

Altered Na<sup>+</sup>/K<sup>+</sup>-ATPase expression plays a role in rumen epithelium adaptation in sheep fed hay ad libitum or a mixed hay/concentrate diet

Kuzinski¹,

Žitňan²,

Viergutz³

et al. 2011

Vet. Med. - Czech

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ABSTRACT:In this study we investigated rumen papillae morphology and the localization and expression of the Na + /K + -ATPase in eight sheep fed hay ad libitum (h) or hay ad libitum plus additional concentrate (h/c). Four sheep were provided with the ad libitum h-diet for the complete three-week experimental period. The second group of four sheep received the h-diet for only one week and was fed the mixed hay/concentrate (h/c) diet for another two weeks. The amount of concentrate supplement was stepwise increased from 150 to 1000 g/day and given in two meals. Following slaughter rumen papillae from the atrium ruminis (AR), the rumen ventralis (RV) and the ventral blind sac (BSV) were fixed and examined for morphological changes and Na + /K + -ATPase localization by morphometric methods and immunohistochemistry. Ruminal epithelial cells (REC) originating from the strata basale to granulosum were also isolated. Cellular Na + /K + -ATPase expression (mRNA and protein) and differentiation state were determined by RT-PCR, Western blot, and flow cytometry. Compared with data from h-fed sheep, morphometric analysis revealed an increased length and width of rumen papillae in h/c-fed sheep, resulting in a marked 41% and 62% increase in rumen papillae surface in AR and RV, respectively. The rumen mucosa of h/c-fed sheep was characterized by a predominant stratum corneum (42 ± 0.7 µm vs. 28 ± 0.5 µm), but the thickness of the metabolically active cell layers remained unchanged. REC suspensions from sheep fed the h/c diet generally contained more cells (7.30 ± 0.83 vs. 3.49 ± 0.52 × 10 7 /ml; P < 0.001) and an increased proportion of REC positive for basal cytokeratin and for the differentiation marker cytokeratin 10 (P < 0.05). Cellular (cell membrane) and epithelial (stratum basale to stratum granulosum) Na + /K + -ATPase localization was similar between rumen regions and was not changed by concentrate feeding. After two weeks on the h/c-diet, a 96% increase in the absolute number of Na + /K + -ATPasepositive REC (6.56 ± 0.84 vs. 3.35 ± 0.51 × 10 7 /ml; P = 0.003) and a 61% elevation (P = 0.043) in Na + /K + -ATPase protein expression in REC from the upper third of the suprabasal cell layers were found. Moreover, a two-fold (P = 0.001) elevation in cell membrane surface area accompanied by a reduction (1.19 × 10

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“…The reason for this difference has not been elucidated but might be attributable to: (1) higher absorption of certain dietary components in jejunum, (2) increase in cell proliferation, (3) feed consistency or (4) small intestinal microbiota. Recently, reindeer have been demonstrated to eat more when fed RF-80 compared with lichen (Storeheier et al 2003). This increase in food intake may increase the passage time through the small intestine and increase cell proliferation as observed in pigs (Diamond and Karasov 1983).…”

Section: Discussionmentioning

confidence: 90%

“…Detailed descriptions of animals and feeding are described elsewhere (Storeheier et al 2003). The animals used in the present study were killed for other scientific purposes (Storeheier et al 2003). They were stunned with a captive bolt pistol and killed by bleeding.…”

Section: Methodsmentioning

confidence: 99%

Effects of natural winter pasture and commercial pellet on the ultrastructure of small intestinal epithelium in reindeer

et al. 2005

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Segments of small intestine (duodenum, jejunum and ileum) from slaughtered reindeer (Rangifer tarandus tarandus) grazing natural winter pastures (n=3) and reindeer fed commercially available pellets (RF-80) in winter (n=5) were collected and immediately fixed in McDowell's fixative. Transmission electron microscopy was employed to investigate the ultrastructural features of the epithelium and lamina propria along the small intestine and to relate these to the different diets. Major differences in ultrastructural features were observed between the small intestinal enterocytes of reindeer fed the two diets. Enterocytes in reindeer fed the natural diet displayed a normal appearance with a dense cytoplasm and distinct microvilli. In contrast, reindeer fed the commercial diet showed damaged enterocytes amongst the normal cells. Abnormal changes included disintegration and loss of microvilli, cytoplasmic swelling, loss of membrane integrity and increases in the width of intercellular spaces, especially in the jejunum.

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Effects of seasonal changes in food quality and food intake on the transport of sodium and butyrate across ruminal epithelium of reindeer

Cited by 18 publications

References 25 publications

Transport of cations and anions across forestomach epithelia: conclusions from in vitro studies

Transport of cations and anions across forestomach epithelia: conclusions from in vitro studies

Altered Na<sup>+</sup>/K<sup>+</sup>-ATPase expression plays a role in rumen epithelium adaptation in sheep fed hay ad libitum or a mixed hay/concentrate diet

Effects of natural winter pasture and commercial pellet on the ultrastructure of small intestinal epithelium in reindeer

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