Numbers of M1 and M2 macrophages in TA muscle are modified by blood monocyte depletion. Rats were treated once a day with intravenous injection of liposome-encapsulated clodronate starting 24 h prior to injury until euthanasia at 1, 2, 3 and 4 d post-injury, for analysis of M1 and M2 macrophage accumulation into injured muscle. (A) Gating strategy (at 3 d post-injury) in single cell suspensions from skeletal muscles was based on omission of primary antibody for CD11b, and on isotype control stainings for CD68 and CD163 to identify M1 (CD163-) and M2 (CD163+) subsets. Liposome-encapsulated clodronate induced a significant decrease in accumulation of M1 (B) and M2 (C) macrophages at 2 d post-injury and a significant increase in M1 macrophage number at 4 d post-injury. *Significantly different from non-depleted groups, Student’s t-test, p < 0.05. n = at least 3, for all the time points and conditions evaluated.