Effects of L-lactate on the morphology, hormone concentration and gene expression. GC were cultured with L-lactate (30 mM) supplementation compared to the corresponding vehicle control in a standardized serum-free culture system for 8 days. (a-b) Cultured cells displayed a typical GC-like morphology and tended to form clusters. (c) Hormone profiles of L-lactate treated cells indicated relatively to the control (dashed line). The concentration of E2 (in ng/ml) was significantly decreased relative to the vehicle control (dashed line). (d) The expression of selected marker genes was specifically regulated in L-lactate treated cells as compared to the vehicle control (dashed line). The transcript abundance was normalized to the reference gene RPLP0. Means and SEM are shown of n = 3 replicates, *P < 0.05, student t-test or Mann-Whitney test.