ABSTRACT
Objective To study the expression of activator protein-1(AP-1)and connexin 43(Cx43)in uterine smooth muscle of term pregnancy and its relationship with preterm delivery.Methods Immuno-histochemistry was applied for 15 uterine smooth muscle samples of term pregnancy without labor(Group Ⅰ),15 of term pregnancy in labor(group Ⅱ)and 10 of preterm delivery in labor(group Ⅲ)to investigate the expression of two subunits of AP-1(c-Jun and c-Fos)and Cx 43. Results (1)The expression of Cx43 in group Ⅰ and Ⅱ(4.33±0.51 and 4.20±0.42)were significantly higher than that in group Ⅲ(3.15±0.41,P<0.01).Lable index of c-Jun protein in group Ⅲ,Ⅱ and Ⅰ was(52.34±4.18)%,(45.25±5.24)%and(34.14±4.26)%,respectively (P<0.01),and the lable index of c-Fos protein was(53.48±4.36)%,(43.32±6.21)%and(31.29±3.34)%,respectively(P<0.01).Positive correlation was found between the expression of Cx43and c-Jun,c-Fos in pregnancy uterine smooth muscle(r=0.65,0.63,P<0.01). ConclusionsThe Cx43 plays an important role in the onset of labor.The expressions of Cx43 is positively related with the expression of AP-1 in pregnancy uterine smooth muscle.