Expression of lactate dehydrogenase A (LDHA) and lactate transporters (MCT1 and MCT4) in injured tendons. The longitudinal sections of injured tendons (1 and 4 weeks [1w and 4w] after surgery) and uninjured tendons were subjected to (A, E, I, M, Q) hematoxylin and eosin (HE) staining and immunostaining for (B, F, J, N, R) LDHA, (C, G, K, O, S) MCT1, and (D, H, L, P, T) MCT4. The images were taken at the edges (stub) and midsubstance of tendons. Strong immunoreactivity of LDHA, MCT1, and MCT4 in (A-L) 1 week–injured tendons remained in (M-P, circles) chondroid lesions at edges and (Q-T, circles) the region with high cell density at midsubstance 4 weeks after injury. The scale bar, 100 μm.