Day 9 Research Articles

MHC class I genes transcribed in the murine placenta

Uterine transplantation (UTx) has been proposed as a treatment option for women diagnosed with absolute uterine factor infertility (AUFI). The goal of UTx remains achieving pregnancy and live birth of a healthy neonate following allogeneic UTx. Our aim was to assess whether fertility was possible following allogeneic uterine transplantation (UTx), when the recipient had demonstrated long-term survival and had been administered immunosuppression.Nine allogeneic UTx in New Zealand White rabbits were performed using a pre-determined protocol. Tacrolimus was the immunosuppressant selected. Embryos were transferred into both cornua of the sole living recipient via a mini-midline laparotomy. The pregnancy was monitored with regular reproductive profiles and serial trans-abdominal ultrasound to measure conceptus growth (gestation sac and crown rump length (CRL)).In the sole surviving doe a gestation sac was visualised on ultrasound from Day 9 (D9) after embryo transfer. Gestation sac diameter and CRL increased from D9 to D16 but by D18 the gestation sac had reduced in size. The fetus was no longer visible, suggesting fetal resorption had occurred. Subsequent scans on D22 and D25 did not demonstrate a gestation sac. Scheduled necropsy on D27 and histopathology confirmed evidence of a gravid uterus and presence of a gestational sac. A single episode of acute rejection occurred on D13.Pregnancy was achieved after rabbit allogeneic UTx but serial ultrasound suggested that fetal demise occurred prior to scheduled necropsy. The study represents only the third example of conception and pregnancy following an animal allogeneic UTx.

Evidence that cellular proliferation contributes to relaxin-induced growth of both the vagina and the cervix in the pregnant rat.

It is well established that cervical growth during rat pregnancy is relaxin dependent. The first objective of this study was to determine if relaxin also promotes vaginal growth in the pregnant rat. Finding that this is the case, the second objective of this study was to determine if cell proliferation accompanies relaxin-dependent vaginal and cervical growth during rat pregnancy. Primiparous pregnant rats were ovariectomized (O) or sham ovariectomized (group C) on day 9 (D9) of pregnancy, before relaxin (R) is detectable in the peripheral circulation. After ovariectomy, rats were treated continuously with progesterone (P) and estrogen (E, group OPE), or P, E, and porcine R (group OPER) in doses that restored normal pregnancy and parturition parameters. P and E were administered via silicon tubing implants. R was administered from miniature osmotic pumps. Vaginas and cervices were collected on D9 and D22 from group C, and on D22 from groups OPE and OPER (n = 6/group). Vaginas and cervices were weighed, frozen, and lyophilized until dry. Dried tissues were weighed, homogenized, and their DNA contents were determined. In sham-operated controls (group C), the wet weight, dry weight, and DNA contents of both the vagina and cervix increased 50-300% from D9-D22. On D22, vaginal and cervical wet and dry weights were significantly lower than controls in R-deficient group OPE; whereas, they were greater than controls in group OPER. Similarly, on D22, vaginal and cervical DNA content did not differ from D9 controls in group OPE; whereas they exceeded D22 controls in group OPER. In conclusion, this study demonstrates that vaginal growth during the second half of rat pregnancy is R dependent. Additionally, this study provides evidence that R may contribute to both vaginal and cervical growth by promoting cellular proliferation.

Evidence that cellular proliferation contributes to relaxin-induced growth of both the vagina and the cervix in the pregnant rat

It is well established that cervical growth during rat pregnancy is relaxin dependent. The first objective of this study was to determine if relaxin also promotes vaginal growth in the pregnant rat. Finding that this is the case, the second objective of this study was to determine if cell proliferation accompanies relaxin-dependent vaginal and cervical growth during rat pregnancy. Primiparous pregnant rats were ovariectomized (O) or sham ovariectomized (group C) on day 9 (D9) of pregnancy, before relaxin (R) is detectable in the peripheral circulation. After ovariectomy, rats were treated continuously with progesterone (P) and estrogen (E, group OPE), or P, E, and porcine R (group OPER) in doses that restored normal pregnancy and parturition parameters. P and E were administered via silicon tubing implants. R was administered from miniature osmotic pumps. Vaginas and cervices were collected on D9 and D22 from group C, and on D22 from groups OPE and OPER (n = 6/group). Vaginas and cervices were weighed, frozen, and lyophilized until dry. Dried tissues were weighed, homogenized, and their DNA contents were determined. In sham-operated controls (group C), the wet weight, dry weight, and DNA contents of both the vagina and cervix increased 50-300% from D9-D22. On D22, vaginal and cervical wet and dry weights were significantly lower than controls in R-deficient group OPE; whereas, they were greater than controls in group OPER. Similarly, on D22, vaginal and cervical DNA content did not differ from D9 controls in group OPE; whereas they exceeded D22 controls in group OPER. In conclusion, this study demonstrates that vaginal growth during the second half of rat pregnancy is R dependent. Additionally, this study provides evidence that R may contribute to both vaginal and cervical growth by promoting cellular proliferation.

The physiological role of relaxin in the pregnant rat. IV. The influence of relaxin on cervical collagen and glycosaminoglycans.

Changes in the collagen and glycosaminoglycan components of cervical connective tissue were studied in nonpregnant, intact pregnant, and ovariectomized hormone-treated pregnant rats. Collagen concentration and solubility and the concentration of the glycosaminoglycans dermatan sulfate (DS), heparan sulfate, and hyaluronic acid (HA) in cervices taken from day 9 (D9) pregnant rats were similar to those in cervices from nonpregnant rats. In cervical tissue from late pregnant intact control rats on D18 and D22, the collagen concentration decreased, collagen solubility increased, and there was no significant change in total glycosaminoglycan concentration. In cervices from ovariectomized pregnant rats treated with progesterone and estrogen, collagen and glycosaminoglycan parameters resembled those of D9 and nonpregnant cervices on both D18 and D22. However, treatment of ovariectomized pregnant rats with progesterone, estrogen, and porcine relaxin (R) restored cervical collagen concentrations to those of intact controls on both D18 and D22. On D18 of pregnancy, cervical collagen solubility was partially increased by R treatment, and by D22, it was similar to that of intact D22 pregnant controls. R treatment also resulted in a significantly increased cervical concentration of HA. It is concluded that the decrease in collagen concentration, increase in collagen solubility, and increase in HA concentration resulting from R action may contribute in part to the increased extensibility of the cervix that occurs during late pregnancy in the rat.