Related Experiment Video
Updated: Feb 12, 2026

Clinical Examination Protocol to Detect Atypical and Classical Scrapie in Sheep
Published on: January 19, 2014
Absorption of bicarbonate in sheep omasum
Driton Caushi1, Holger Martens1
1Freie Universitaet Berlin, Department of Veterinary Physiology, Oertzenweg 19b, 14163 Berlin, Germany.
Abstract:
Transport of bicarbonate across the isolated epithelium of sheep omasum was studied in vitro in Ussing chambers in combination with the pH-Stat method. The transport of HCO3- occurred in both directions, but Jms HCO3- was significant larger than Jsm. Reducing the activity of the apical Na/H exchanger by a low mucosal Na concentration caused a significant reduction of Jms HCO3-. Mucosal amiloride or short chain fatty acids (25 mmol l-1 SCFA) numerically decreased Jms HCO3-, but their combination (amiloride + SCFA) caused a significant reduction, which was also observed after addition of the carboanhydrase inhibitor ethoxyzolamide. Concentrations of 5 or 15 mmol·l-1 mucosal ammonia did not change transport rates. The obtained results indicate the importance of an undisturbed cytosolic pH for transcellular HCO3- transport, which is probably mediated by an anion exchanger in both the apical and basolateral membranes. Possible impairment of HCO3- transport appears to be an overlooked factor in the pathogenesis of displacement of the abomasum.
Related Concept Videos
Cloning of Dolly the Sheep
Roles of Electrolytes: Chloride and Bicarbonate
Conditions such as hypochloremia can arise from insufficient chloride reabsorption by the kidneys, often compounded by extended bouts of diarrhea, vomiting,...
Bicarbonate-Carbonic Acid Buffer
Drug Absorption: Factors Affecting GI Absorption
Absorption of Radiation
Protein Absorption

