Fig. 4. RV pressure and RV/LV+S ratio in MCT-induced PAH rats according to dose of hUCB-MSCs. (A) RV pressure was significantly decreased in UA, UB and UC groups at weeks 2 and 4. There was no significant difference among the three groups. (B) RV/LV+S ratio slightly decreased in UA, UB and UC groups. ^*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, left ventricle; S, septum; C, control group; M, monocrotaline group; UA, 3×10⁶ cells/rat; UB, 1.5×10⁶ cells/rat; UC, 3×10⁵ cells/rat.