Effect of bicarbonate and furosemide on chloride accumulation by the intestine of the freshwater turtle Mauremys caspica.
The influence of HCO3- on Cl- absorption by the intestine of the freshwater turtle Mauremys caspica has been studied. Na+, K+ and Cl- intracellular concentrations together with transepithelial potential difference were measured. In HCO3--free medium, transepithelial potential difference was serosal positive. A reversal in the sign of the transepithelial potential difference was observed in HCO3- medium. A subsequent addition of 10(-3) M furosemide to HCO3- medium blocked, at least partially, this response. However, neither the presence of HCO3- nor addition of 10(-3) M furosemide to HCO3+ medium had any effect on Na+, K+ or Cl- intracellular concentrations. These results are discussed in relation to the presence of a Cl-/HCO3- exchange process.
D000818:Animals; D001639:Bicarbonates / Q000494:pharmacology*; D002712:Chlorides / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology*; D066298:In Vitro Techniques; D007408:Intestinal Absorption / Q000187:drug effects*; D007413:Intestinal Mucosa / Q000378:metabolism*; D007424:Intracellular Fluid / Q000032:analysis; D008564:Membrane Potentials; D011188:Potassium / Q000032:analysis; D012964:Sodium / Q000032:analysis; D014426:Turtles / Q000378:metabolism*
D001639:Bicarbonates; D002712:Chlorides; D005665:Furosemide; D012964:Sodium; D011188:Potassium