Effects of amino acid-modifying agents on the transport system for L-lactate in hMCT4-expressing oocytes.

Oocytes were preincubated at 25°C for 10 min with DTNB (pH 7.0), for 10 min with DTT (pH 7.5), for 10 min with PMSF (pH 7.4), for 30 min with EDC (pH 5.5), for 10 min with PLP (pH 7.5) or for 15 min with PGO (pH 8.0). L-lactate uptake was measured after treatment with the indicated concentrations of modifying agents. The oocytes were incubated for specified periods at 25°C with transport buffer containing 0.1 mM L-lactate. EDC with glycine methyl ether (GME)* and GME alone (data not shown) had no effect on L-lactate uptake. Data are expressed as a percentage of control in the absence of a modifying agent and are the means ± S.E. of three – five experiments.
*: GME was synthesized by esterification of methanol and glycine.