Exogenous gonadotropin administration affects the glycocalyx of rat endometrial epithelial cells during the period of implantation.

PURPOSE: Exogenous gonadotropins which cause superovulation are known to effect endometrial morphology, including the glycocalyx of surface epithelial cells. Certain of the carbohydrates in the glycocalyx of surface epithelial cells may be involved in the attachment and implantation of the blastocyst. METHODS: The effect of exogenous gonadotropins on specific carbohydrates in the glycocalyx of the rat endometrium around the time of implantation was investigated. Lectin-avidin-biotin-ferritin cytochemistry was used to ascertain which carbohydrates were affected. The lectins soybean agglutinin, fucose binding protein and wheat germ agglutinin were used. RESULTS: Statistically significantly less lectin was associated with the apical membrane of surface epithelial cells of animals following hyperstimulation than in noninjected pregnant animals. CONCLUSIONS: The reduction in the carbohydrates contributes to a reduced receptivity of the endometrium for the blastocyst.

Hyperstimulation affects vascular permeability at implantation sites in the rat endometrium.

PURPOSE: It has previously been shown that deleterious changes occur in the epithelium and stroma of the endometrium of the rat following ovarian hyperstimulation by exogenous gonadotropins. The purpose of the present study was to investigate the formation of possible implantation sites following hyperstimulation. Female rats (n = 8) were injected in phase with their estrous cycle with follicle stimulating hormone (FSH), followed by human chorionic gonadotropin (hCG), and mated at proestrous. Control rats (n = 6) were uninjected and mated at proestrous. Animals were killed at 5.5 days of pregnancy. The pontamine blue technique was used to demonstrate the permeability of the uterine vessels. Implantation sites were demonstrated in the uterine horns of all control animals by segmental blue banding. RESULTS: Blue staining occurred only in a portion of one horn of one hyperstimulated animal. While fenestrations were found in the walls of capillaries of control animals, similar fenestrations were not observed in the vessels of hyperstimulated animals. CONCLUSION: As the walls of vessels in the hyperstimulated animals failed to become permeable, and as no implanting embryos were found in these animals, it is concluded that there was an inability of the endometrium to form implantation sites. These changes may impede attachment and implantation of the embryo.

Dose-dependent effects of exogenous gonadotrophins on the endometrium of the rat.

We compared the serum levels of oestrogen and progesterone and the endometrial morphology of normal pregnant rats at 5,5 days' gestation with those of pregnant rats given either low (10 IU) or high (20 IU) doses of two gonadotrophins: follicle-stimulating hormone (FSH) and human chorionic gonadotrophin (HCG). Evidence of ovarian hyperstimulation was observed in the high- but not the low-dose group; both treatment regimens caused significant changes in the endometrial surface, epithelial height, the microvillous border, the glycocalyx, the subepithelial stromal cells and the mitotic activity of the surface epithelial and stromal connective tissue cells. The effects of the high-dose treatment were more severe than those of the low-dose treatment. The serum oestradiol and progesterone levels of the treated groups were not significantly different from those of the control group. The changes in the endometrium after both treatment regimens may interfere with normal trophoblastic-endometrial interactions and could influence the maintenance of pregnancy. This investigation demonstrated that even low doses of gonadotrophins, which do not cause obvious ovarian stimulation, affect uterine morphology. The findings have important implications for in vitro fertilisation and embryo transfer programmes.

Detection of Candida cell forms in Pap smears during pregnancy.

In a prospective study of 124 urban black pregnant women, 43% had Candida isolated from endocervical cultures and 20% had Candida cell forms on cytological Pap-stained cervical specimens. The presence of Candida cell forms on Pap smears had a better correlation with Candida colonisation when normal lactobacillary flora was present, when Trichomonas vaginalis parasites were absent and when the infecting Candida species was C. albicans. Positive cultures were strongly related to a number of clinical signs and symptoms, but Pap smears were not. Neither Candida culture nor Candida cells in Pap smear revealed an association with premature delivery, birth weight, severe neonatal morbidity or mortality. We confirm that the routine cervical Pap smear is not a sensitive method for diagnosing symptomatic fungal infection. More specifically, some of the Pap smear characteristics, such as disturbed lactobacillary flora or co-infection with T. vaginalis, interfere with accurate diagnosis.

The association between Chlamydia cervicitis, chorioamnionitis and neonatal complications.

In a prospective study on genital infections, the influence of Chlamydial cervicitis on pregnancy outcome was evaluated. In eleven women with Chlamydial cervicitis perinatal outcome was recorded, the placenta was examined and the newborns were screened for Chlamydial conjunctivitis. They were compared with 13 women who were negative for Chlamydia and were delivered immediately after a Chlamydia positive woman. Compared to negative women, women with Chlamydia cervicitis were younger and presented for antenatal care at a later gestational age (difference not significant) and started having sexual intercourse at an earlier age (P less than 0.02). There was a significant association between Chlamydial infection and chorioamnionitis, lower birth weight and severe neonatal infection (P less than 0.05); but a contribution from concomitant genital pathogens could not be completely ruled out. Therefore a screening program for Chlamydia should include screening for other genital infections. While almost all cases of Chlamydia could have been suspected by this technique, a screening based on lactobacillary grades in Pap smears might be helpful for this purpose, even more so because it also facilitates tracing other genital pathogens. Detection of Chlamydial antigen from conjunctival swabs taken immediately after birth did not adequately reflect the risks of neonatal infection in this small group.

Differential size distribution of atrial dense granules in spontaneously hypertensive, Wistar-Kyoto and Wistar rats.

The differential size distribution of atrial dense granules (ADGs) in spontaneously hypertensive rats (SHR) and two normotensive controls, Wistar and Wistar-Kyoto (WKY) rats, was investigated. The ADGs in SHR were smaller than those in Wistar rats. The ADGs of WKY rats were of intermediate size. It is possible that ADGs are more rapidly secreted in SHR compared with WKY and Wistar rats or that the smaller-diameter granules may contain more atriopeptinogen than the larger granules. The intermediate size of the ADGs in WKY suggests that the WKY variant is morphologically intermediate between the SHR and Wistar strains.