Lactate carriers in the artificially perfused human term placenta

Carrier-mediated transport of monocarboxylic acids in BeWo cell monolayers as a model of the human trophoblast

“…These observations are in good agreement with the lactate transport studies performed in the perfused human placental lobe model. 15 Further, our studies suggested a functional asymmetry in the carrier mechanism.…”

“…Using brush border membrane preparations, a functional, proton-dependent MCT has been observed in tissues from rat 12,13 and human 14 placenta. A functional, bidirectional, and carrier-mediated mechanism for lactic acid, presumably a MCT, has also been demonstrated in the perfused human placental lobe model 15 . In addition to the transport of lactic acid, 11,14,15 a MCT at the placental barrier presents a potential mechanism by which monocarboxylic acid drugs and drugs of abuse may readily distribute between maternal and fetal compartments.…”

“…The establishment of functional MCT mechanisms in the BeWo cells offers the opportunity to characterize mechanisms of monocarboxylic acid transport at the molecular and biochemical level, extending limited studies performed with brush border preparations [12][13][14] and the perfused human placental lobe. 15 The processing of benzoic acid by the BeWo monolayers was characterized by saturable uptake and transport. The processes were significantly inhibited by metabolic inhibitors and indicated that benzoic acid uptake is energy dependent.…”

“…14,15 Monocarboxylic acids are transported out of muscle and into liver (i.e., the so- Each value represents the mean ± standard deviation of four experiments. * P < 0.001 versus untreated control (100%).…”

Cellular Expression of the Monocarboxylate Transporter (MCT) Family in the Placenta of Mice

“…Among the glucose transporter isoforms, GLUT1 and GLUT3 are 4 localized in the cell membrane of syncytiotrophoblasts in mammals [9,10]. Another set of placental perfusion studies and isolated plasma membrane studies have demonstrated that lactate is transferred across the placental barrier by means of streospecific (between L-and D-lactate) transporters [11][12][13], and the movement is mediated by a carrier-dependent transporter resembling the lactate/H + co-transporters with a broad distribution throughout the body.…”