Expressions of candidate molecules in the human fallopian tube and chorionic villi of tubal pregnancy exposed to levonorgestrel emergency contraception

Abstract

Background: Cases of ectopic pregnancy (EP) following levonorgestrel (LNG) emergency contraception (EC) failure were reported, however, the effects of LNG on tubal microenvironment or chorionic villi in EP have not yet been documented.

Methods: Fifty-five women with tubal pregnancy were divided into two groups according to whether LNG-EC was administrated during the cycle of conception. The serum concentrations of beta-hCG, E2 and P were measured. The mRNA and protein expressions of estrogen and progesterone receptors, leukemia inhibitory factor, vascular endothelial growth factor, inducible nitric oxide synthase, and endocannabinoid receptor - CB1 in the ectopic implantation site and chorionic villi were examined.

Results: Compared to those unexposed to LNG-EC, women with tubal pregnancy exposed to LNG-EC during the cycle of conception had no statistically significances in the serum concentrations of beta-hCG, E2 P, nor in the pathological types of tubal pregnancy or the expressions of ER-alpha, PR, LIF, VEGF, iNOS and CB1.

Conclusions: The expressions of candidate molecules in the fallopian tube and chorionic villi were not altered by exposure to LNG-EC. A routine therapy with no additional intervention might thus be applied to tubal pregnancy exposed to LNG-EC.

Figure 1

Quantitative real-time PCR analysis of mRNA expression in chorionic villi and the implantation site in fallopian tube of tubal pregnancy. There were no significant differences between the two groups in the mRNA expressions of estrogen receptor (ER)-alpha, progestogen receptor (PR), leukemia inhibitory factor (LIF), vascular endothelial growth factor (VEGF), inducible nitric oxide synthase (iNOS), and endocannabinoid receptor 1 (CB1) in chorionic villi and the implantation site in fallopian tube of tubal pregnancy. All mRNA expression values were normalized against the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) endogenous control gene.

Figure 2

Immunostaining of the chorionic villi in tubal pregnancy. Expressions of estrogen receptor (ER)-alpha (A, B), progestogen receptor (PR) (C, D), leukemia inhibitory factor (LIF) (E, F), vascular endothelial growth factor (VEGF) (G, H), inducible nitric oxide synthase (iNOS) (I, J) and endocannabinoid receptor (CB1) (K, L) in the chorionic villi observed by immunohistochemistry. Positive staining was detected in the chorionic villi from both the LNG-EC group (A, C, E, G, I) and the control group (B, D, F, H, J). The immunostaining for ER-alpha (A, B) and PR(C, D) was observed in the nuclei of cytotrophobast, syncytiotrophoblast, and stromal cells from both groups. The immunostaining for LIF (E, F), VEGF (G, H), iNOS (I, J) and CB1 (K, L) was seen in the cytoplasm of cytotrophobast, syncytiotrophoblast, and stromal cells from both groups. There were no significant differences between the two groups in the expressions of ER-alpha (A, B), PR (C, D), LIF (E, F), VEGF (G, H), iNOS (I, J) or CB1 (K, L). Magnification: 400×.

Figure 3

Immunostaining of the implantation site in the fallopian tube in tubal pregnancy. Representative images showing immunoreactivity of estrogen receptor (ER)-alpha (A, B), progestogen receptor (PR) (C, D), leukemia inhibitory factor (LIF) (E, F), vascular endothelial growth factor (VEGF) (G, H), inducible nitric oxide synthase (iNOS) (I, J), and endocannabinoid receptor (CB1) (K, L). Positive immunolabeling was detected in the epithelial and stromal cells from both the LNG-EC group (A, C, E, G, I) and the control group (B, D, F, H, J). The immunostaining for ER-alpha (A, B) and PR (C, D) was observed in the nuclei of the epithelial and stromal cells from both groups. The positive staining for LIF (E, F), VEGF (G, H), iNOS (I, J), and CB1 (K, L) was found in the cytoplasm of the epithelial and stromal cells from both groups. No significant differences were observed in any of the immunoreactivity of ER-alpha (A, B), PR (C, D), LIF (E, F), VEGF (G, H), iNOS (I, J), or CB1 (K, L) between the two groups. Magnification: 400×.