Figure 4. Lactic acid effects are dependent on MCT-1, lactate, and H⁺ ions.

A) BMMC were treated ± AR-C155858 (100 nM) or DMSO (vehicle) for 1 hour, ± lactic acid (12.5) mM for 16 hours, and activated ± LPS (1 μg/mL) for 16 hours. B) BMMC were treated ± 12.5 mM lactic acid, sodium lactate, or formic acid for 24 hours, then activated ± LPS (1 μg/mL) for 16 hours. C) BMMC were treated with varying doses of sodium lactate for 24 hours and activated with LPS (1 μg/mL) for 16 hours. D) Lactic acid was added to cell culture media with BMMC plated at 1×10⁶/mL. pH was measured over 4 hours. Dashed line indicates starting pH. E) BMMC were treated ± 12.5 mM lactic acid (LA) for 24 hours, then re-plated in new media ± 12.5 mM lactic acid and activated ± LPS (1 μg/mL) for 16 hours. ELISA was used to measure cytokine concentrations in the cell supernatant. Data are means ± SEM of 3 populations, representative of 3 independent experiments. *p < .05, **p < .01, ***p < .001, ****p < .0001, NSD= no significant difference