Evidence for apical Na+/H+ exchanger in bovine main pancreatic duct
Autor: | V Silviani, R Ducroc, C. Marteau, Crotte C, A Gerolami |
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Rok vydání: | 1995 |
Předmět: |
Nystatin
medicine.medical_specialty Sodium-Hydrogen Exchangers Physiology Sodium chemistry.chemical_element In Vitro Techniques Ouabain Amiloride Internal medicine medicine Animals Secretion Pancreatic duct Pancreatic Ducts Gastroenterology Sodium–hydrogen antiporter medicine.anatomical_structure Endocrinology chemistry Pancreatic juice Cattle Pancreas medicine.drug |
Zdroj: | Digestive Diseases and Sciences. 40:2336-2340 |
ISSN: | 1573-2568 0163-2116 |
DOI: | 10.1007/bf02063234 |
Popis: | The finding of a high PCO2 in basally secreted pancreatic juice of man and dog raises the hypothesis of proton secretion from ductal epithelial cells presumably through a Na+/H+ exchanger. To test this possibility, H+ luminal secretion and Na+ movements were measured in vitro on samples of bovine pancreatic ducts mounted in Ussing-type chambers. The rate of luminal acidification measured by the pH stat method, using bicarbonate-free media gassed with 100% O2, reached 2.75 muEq/cm2/hr. Proton secretion was blocked in the presence of 1 nM amiloride or in the absence of Na+ (replaced by choline) in the mucosal solution. Study of transepithelial 22Na fluxes in short-circuited tissue, bathed on both sides by control Ringer solution, gassed by 95% O2-5% CO2 demonstrated a net sodium transport from the mucosal to the interstitial side of the duct (net 22Na flux = 3.23 +/- 0.8 muEq/cm2/hr). This net sodium transport was electroneutral and blocked by mucosal amiloride (0.5-1 mM/liter) or by interstitial ouabain (1 mM/liter). These results are consistent with the existence of a Na+/H+ exchanger on the luminal side of the bovine main pancreatic duct. |
Databáze: | OpenAIRE |
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