Influence Of Chlamydial Infection On Early Pregnancy Of Rats

Objective To study the influence and mechanism of CT infection on pregnancy by detecting the expression of heat shock protein (Hsp) 70, integrin ₄β₁ and estradiol receptor in rat endometrium during early pregnancy after the Chlamydia Trachomatis (CT) infection.Matereial and Methods The Wistar female rats (200-250g body weight) were inoculated into the vagina with Chlamydia Trachomatics, immunotype H, then their clinic symptom were observed and the number of the young rat were calculate after the female rats were pregnant. And the uteri of nonpregnant rat and day 4⁸ of pregnancy rat after the CT infection and day 4-8 of normal pregnancy rat were sectioned. Immunohistochemical method was used in the experiment to study the influence of CT infection on expression of Hsp70, integrin ₄β₁ and estradiol receptor of early pregnancy.Results 1. Rats infected with 10⁶ ICU of Chlamydia Trachomatis showed signs of lethargy, hunched posture, and ruffled hair starding day 13 of pregnancy, the controls showed no clinical abnormalities. The mean gestation times at which delivery occurred for trial group were days 20 . To compared with control group, it's no significant differences. The numbers of babies born per pregnant rat were 6-8 in trial group, 9-13 in control group. The mean number of babies born in trial group is smaller than in control group (p<0.01), the difference is significant. No significant differences were observed in the mean body weight or length between the trial group and the control group. 2. Hsp70 mainly distributed in the cytoplasm of stroma cells and decidual cells of endometrium lamina propria of pregnant rat and nonpregnant rat; integrin a₄β₁ distributed in the cytomembrane of the endometrium epithelium, glandular epithelium and stroma cells; ER mainly distributed in the nucleus, less in the cytoplasm of the endometrium epithelium, glandular epithelium and stroma cells of pregnant rat and nonpregnant rat. 3. The positive expression of Hsp70 in endometrium of pregnancy rat after the CT infection (trial group) is stronger than that in normal pregnancy rat (control group) from 4d to 6d and normal rat. The difference is significant (p<0.01);To be compared with control group, it's no significant difference during 7d⁸d, but it's stronger than that in normal rat. However,The positive expression of integrin a^i and ER in trial group was weaker than that in control group during 4d⁶d, especially in 5d; and stronger than that in normal rat, the difference was significant (p<0.01); The change trend of integrin a^i expression was the same as the expression of ER, and was contrary to that of Hsp70. 4. The positive correlation among the integrin a$i expression-. Hsp70 expression and ER was outstanding (P<0.05) .Conclusion 1. The mean number of babies born in trial group is smaller than in control group and the clinical abnormalities of the trial group proved the influence of CT infection on pregnancy, and the influence may disturb the blastocyst implantation or cause forepart abortion. 2. The CT infection in rat reproductive duct cause high expression of Hsp70 during the period of blastocyst implantation(4d⁶d) and cause low expression of integrin a^i and ER . We suppose that CT infection in reproductive track can influence the blastocyst implantation during early pregnancy, and the bad pregnancy outcome is result from the coaction of Hsp70 and integrin a^i which has some relation with the body hormone regulation.