Proton-lactate cotransport in basolateral membrane vesicles from rat jejunum.
Proton-coupled lactate transport across the basolateral membrane of rat jejunal enterocyte was studied using well purified membrane vesicles. L-lactate uptake is stimulated by an inwardly directed H+ gradient; the effect of the pH difference is drastically reduced by FCCP and by pCMBS; unlabelled L-lactate causes a strong inhibition, whilst furosemide is uneffective. The H+ gradient-dependent stimulation of L-lactate uptake is significantly inhibited also by SCN-: this finding could explain results recently reported in the literature in which H(+)-lactate symport was not evidenced in basolateral membranes from rat jejunum.
Orsenigo
M N
MN
Dipartimento di Fisiologia e Biochimica Generali, Università di Milano, Italy.
Tosco
M
M
Laforenza
U
U
Faelli
A
A
D002731:4-Chloromercuribenzenesulfonate / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D005665:Furosemide / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007413:Intestinal Mucosa / Q000378:metabolism*; D007583:Jejunum / Q000378:metabolism; D007773:Lactates / Q000378:metabolism*; D008297:Male; D011522:Protons; D051381:Rats; D017208:Rats, Wistar
D002352:Carrier Proteins; D007773:Lactates; D011522:Protons; D002259:Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone; D002731:4-Chloromercuribenzenesulfonate; D005665:Furosemide