Fig. 4

Placental angiogenesis of sows and female mice. Each placental tissue was regarded as an experimental unit (n = 6 per group). A, B H&E staining analysis of blood vessel density in the placental tissue of sows. The black arrow indicates the location of the placental blood vessels. C–E Western blotting analysis of protein expressions of VEGF-A and CD31 in the placentae of sows. F, G H&E staining analysis of the placental labyrinth zone of female mice. H–J Western blotting analysis of protein expressions of VEGF-A and CD31 in the placentae of female mice. All data represent the mean ± SEM. Statistical differences in mean values of all indexes were evaluated by using the independent t-test. 0.05 < P < 0.10 indicated a statistical trend of change; *P < 0.05 and **P < 0.01