Immunohistochemical analysis of the effect of prenatal caffeine on embryonic implantation in rats

Aim: Implantation is one of the most important stages of pregnancy. Many external factors may adversely affect this process. In our daily lives, the consumption of caffeine in many beverages and food is recommended in the pregnancy period. However, the mechanisms of caffeine consumption during pregnancy are not known exactly. In our study, we aimed to investigate the effect of prenatal caffeine consumption on the embryo implantation in rats and the relationship between the molecules involved in implantation stages. Materials and Methods: 45 Wistar albino strains ranging from 200 to 220 grams were used in the study. Pregnant rats were divided into 3 main groups: control, low dose (30mg / kg) and high dose (120mg / kg), representing the dose-dependent effects of caffeine and embryo implantation occurs on day 5 of pregnancy in rats and to evaluate the implantation stages, each main group was divided into 3 subgroups (n=5) to be sacrified on days 4th (pre-implantation), 5th (peri-implantation) and 6th (post-implantation) days, thus 9 groups were created. Immediately prior to sacrification, implantation sites were detected by intravenous Chicago Blue dye. The tissues were embedded in paraffin blocks after fixation with formaldehyde. 5µm thick sections were taken from paraffin blocks. H & E, masson trichrome staining and immunostaining of VEGF, MMP-9, αVβ3 integrin, MUC-1 and HB-EGF molecules, which play an important role in implantation, was performed. Result: Prenatal caffeine consumption in rats resulted in a dose-dependent decrease in the number of implantation sites. It has been shown that the expression of integrin αVβ3 and MMP-9 molecules, which are the markers of implantation, play a role in the etiology. We showed no change in MUC-1, HB-EGF and VEGF expressions. Conclusion: It has been shown that prenatal caffeine consumption in rats decreases embryo implantation in a dose-dependent manner, and the expression of molecules involved in implantation, especially in the high-dose group, has been adversely affected.