Fig. 5

Change in numbers of 3β-HSD-positive steroidogenic cells and macrophage in the CL during luteal stages. Abundant luteal steroidogenic cells immunoreactive for 3β-HSD while a few number of MAC387-positive macrophages are found in the CL at the mid-luteal (ML) stage (a, b). In the CL at the late-luteal (LL) stage, 3β-HSD-positive cells scatters but abundant MAC387-positive cells are distributed (c, d). In the regressed (Reg) CL, both 3β-HSD-positive cells and MAC387-positive cells are negligible (e, f). The number of intact 3β-HSD-positive luteal steroidogenic cells significantly decreases in the regressed CL (g) while MAC387-positive macrophages increase in the CL at the LL stage (h)