Analysis Of The Relationship Between EGF And EGFR And Premature Delivery In Rats

Objective Premature birth is a common complication in obstetrics and gynecology.There are many ways to prevent premature birth,but there is no effective preventive intervention.For a long time,epidermal growth factor(EGF)and epidermal growth factor receptor(EGFR)have been used in obstetrics and Gynecology diseases,such as EGF/EGFR and the occurrence and development of Obstetrics and Gynecology tumors,EGF/EGFR and unexplained recurrent abortion(URSA)and other diseases.However,nowadays,there are few reports on the use of EGF/EGFR in premature delivery.In this study,SD rat pregnant model was established by animal experiments,and LPS was used to establish pregnant rat premature delivery model.The serum and amniotic fluid levels of EGF and the expression of EGFR in placenta of pregnant rats were observed at different gestational and preterm periods.The relationship between EGF/EGFR and natural pregnancy and preterm birth was explored,which provided certain research basis and theoretical basis for the future study of preterm birth.Methods Sixteen healthy adult SD female rats were randomly divided into middle pregnancy group(group A),late pregnancy group(group B),delivery group(group C)and premature delivery group(group D),four in each group,and eight healthy SD male rats,randomly numbered 1-8.Female and male mice were caged at 2:1,from 18:00 PM to 9:00 am,to see the vaginal tie or vaginal sperm smear to determine whether it was the first day of pregnancy.The middle pregnancy group on the 12 th day,the late pregnant group on the 15 th day and the delivery group on the 21 th day were dissected separately,and then 2 ml of venous blood and amniotic fluid were collected by drying tube.Within 24 hours,the upper serum was centrifuged by centrifuge,and stored in refrigerator at-80 ℃ for reserve.At the same time,some placentas were placed in 10%formaldehyde solution,waiting for HE staining pretreatment.Some placentas were placed in RNA protection solution,waiting for RT-PCR pretreatment.The preterm delivery group was injected with lipopolysaccharide(LPS)on the 15 th day of gestation to make the preterm delivery model and collect 2 ml of venous blood and amniotic fluid,with several placentas.The processing method was the same as the above.HE staining was used to observe the placenta tissue of pregnant rats in each pregnancy period,and to compare the pathological changes of placenta between premature delivery rats and each pregnancy period rats.The levels of EGF in serum and amniotic fluid of pregnant rats in each group were detected by double antibody sandwich assay(Elisa),and the relative expression of EGFR in placenta of each group was detected by RT-PCR.Results 1.HE staining showed that there were obvious blood vessel congestion in preterm delivery group and delivery group,However,in the preterm delivery group,there were obvious inflammatory cell infiltration between blood vessel and blood vessel,and between chorion and chorion,which showed pathological changes of chorioamnionitis.Compared with delivery group,the structure was more disordered and the inflammation reaction was more serious.Vascular congestion was not obvious in the middle and late pregnant groups,there was noobvious infiltration of inflammatory cells in both groups,and the structure was clear.Large trophoblast cells could be seen in the middle pregnant groups.2.Elisa results: There was significant difference in serum EGF content among different groups(P<0.05);there was significant difference between delivery group and middle pregnancy group,delivery group and late pregnancy group,delivery group and premature delivery group(P < 0.05);but there was no significant difference between preterm delivery group,middle pregnancy group and late pregnancy group(P > 0.05);there was significant difference in amniotic fluid EGF content among different groups(P < 0.05);there were significant differences between the preterm group and the middle pregnancy group and the late pregnancy group and the delivery group(P < 0.05);but there was no significant difference between the preterm group and the middle pregnancy group(P > 0.05);there was no significant difference between the late pregnancy group and the delivery group(P > 0.05).3.The results of RT-PCR showed that the relative expression of EGFR in placenta was significantly different among different groups(P < 0.05).There were significant differences between two groups in the delivery group and preterm group,middle pregnancy group and late pregnancy group(P < 0.05),there was significant difference between the middle and late pregnancy groups(P < 0.05).4.The relative expression of placental EGFR was positively correlated with serum EGF(r = 0.759,P > 0.05),with amniotic fluid EGF(r = 0.59,P > 0.05),and the serum was positively correlated with amniotic fluid EGF(r = 0.57,P > 0.05).Conclusion 1.EGF and EGFR are dynamic changes in pregnant mice,and the contents of EGF and EGFR gradually increase with the increase of gestational weeks in this study.2.Because of the barrier effect,the sources of serum EGF and amniotic fluid EGF are probably independent of each other.The expressionof placental EGFR is probably related to the level of blood EGF.3.When the contents of EGF and EGFR decrease in late pregnancy,it is probably related to the occurrence of premature delivery.