Fig. 6. RV pressure and RV/LV+S ratio according to treatment timing by low-dose treatment of hUCB-MSCs in MCT-induced PAH rats. (A) RV pressure was decreased in UD, UE, and UF group. (B) No effect on RV hypertrophy by low-dose treatment of hUCB-MSCs in MCT-induced PAH rats. ^*p<0.05, compared with C, ^†p<0.05, compared with M. MCT, monocrotaline; PAH, pulmonary arterial hypertension; hUCB-MSCs, human umbilical cord blood derived mesenchymal stem cells; RV, right ventricle; LV+S, left ventricle+septum; C, control group; M, monocrotaline group; UD, early treatment group of low dose hUCB-MSCs at day 1; UE, dual transfusion group of low dose hUCB-MSCs at day 1 and week 1; UF, reversal treatment group of low dose hUCB-MSC at week 1; hUCB-MSCs, human umbilical cord blood derived-mesenchymal stem cells.