Bicarbonate and chloride transport across rat ileal basolateral membrane.
The mechanisms of HCO3- and Cl- transport across basolateral membranes from rat ileum were investigated in isolated vesicles by means of uptake experiments. Neither Cl-/HCO3- exchanger nor Na(+)-(HCO3-)n cotransport seem to be present in ileal basolateral membranes. Moreover Cl- uptake is unaffected by cis Na+ and/or K+ gradients, indicating the absence of Na(+)-Cl-, K(+)-Cl- and Na(+)-K(+)-2Cl- symport activity. An electrically conductive pathway seems to be responsible for both HCO3- and Cl- fluxes. Evidence is also given for the presence of a Na+/H+ exchanger at the basolateral pole of ileal enterocytes.
Tosco
M
M
Dipartimento di Fisiologia e Biochimica Generali, Università di Milano, Italy.
Orsenigo
M N
MN
Faelli
A
A
D000818:Animals; D001639:Bicarbonates / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism*; D007082:Ileum / Q000378:metabolism*; D007408:Intestinal Absorption; D008297:Male; D008564:Membrane Potentials; D051381:Rats; D017208:Rats, Wistar; D012964:Sodium / Q000378:metabolism
D001639:Bicarbonates; D002712:Chlorides; D012964:Sodium