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Öğe The effects of aglepristone alone and in combination with cloprostenol on hormonal values during termination of mid-term pregnancy in bitches(Elsevier Science Bv, 2014) Kaya, D.; Kucukaslan, I.; Agaoglu, A. R.; Ay, S. S.; Schaefer-Somi, S.; Emre, B.; Bal, Y.This study was designed to assess endocrine changes associated with termination of midterm pregnancy after use of two different protocols. For this purpose we compared the effects of aglepristone (AGL) alone and in combination with cloprostenol (CLO) on serum concentrations of progesterone (P-4), estradiol (E-2) and relaxin (RLN) measured at shortterm intervals during the abortion period in bitches. Fourteen pregnant bitches between day 25 and 32 of gestation were used in the study. In the AGL group (n = 7), aglepristone was administered solely (10 mg/kg body weight (BW), subcutaneously, once daily on two consecutive days) whereas in the AGL-CLO group (n = 7), aglepristone (dosage as in AGL group) and cloprostenol (1 mu g/kg BW, subcutaneously, same with aglepristone) were combined. All pregnancies were successfully terminated 5.2 1.6 days after initiation of treatments, which was significant in both groups (P> 0.05). At the time of the start of abortion (SA) and the end of abortion (EA), the mean P4 concentrations were 26.6 7.3 and 12.0 6.4 ng/ml in AGL group, and 2.7 0.7 and 0.9 0.1 ng/ml, in AGL-CLO group, respectively (P< 0.01). Serum E-2 concentrations were significantly higher (P< 0.05) in AGL group at 42, 48, 54 hand SA after initiation of treatment. In the AGL-CLO group, serum RLN concentrations did not significantly change from the initiation of treatment to EA (P> 0.05). However, markedly higher RLN concentrations (P< 0.05) were observed in the AGL group at 48 h (1.5 0.7 ng/ml) and at SA (1.6 0.5 ng/ml). The results of the present study indicate that changes in the hormonal concentrations affect the mechanism of abortion in different ways. Further in depth studies investigating changes in the expression of hormone receptors inside the ovary, endometrium and placenta might be helpful to our understanding of the endocrinological differences observed in this study. (C) 2014 Elsevier B.V. All rights reserved.Öğe GnRH and its receptor (GnRH-R) are expressed in the canine placenta and uterus(Elsevier Science Inc, 2015) Schaefer-Somi, S.; Kowalewski, M. P.; Kanca, H.; Bozkurt, M. P.; Gram, A.; Sabitzer, S.; Kucukaslan, I.In reproductive tissues, GnRH participates in the regulation of cell growth and proliferation by direct binding to the GnRH-R, which is essential for embryo implantation. However, there is no study on the expression and cellular localization of GnRH and GnRH-R in the canine uterus and placenta. Therefore, bitches were ovariohysterectomized 10 to 12 days after mating (vaginal cytology and progesterone measurement), the uteri were flushed, and if embryos were detectable, bitches were allocated to the embryo positive group (E-pos.; preimplantation, n = 5). Other bitches were operated at later stages and, dependent on the gestational age, either allotted to the post-implantation group (Day 18-25 after mating, n = 9), or the mid-gestation group (Day 30-40 after mating, n = 3). Dogs negative in embryo flushing served as controls (E-neg.; controls, n = 5). Samples of the entire uterine wall were taken from the middle of the horn in E-neg. and E-pos. groups, and from placental and interplacental uterine sites in post-implantation and mid-gestation groups. GnRH-R expression was localized at the mRNA and protein levels by immunohistochemistry and in situ hybridization. The expression of GnRH and GnRH-R mRNA was assessed by semi-quantitative polymerase chain reaction. Additionally, both GnRH and GnRH-R mRNA were expressed in all tissues examined until mid-gestation. Relative expression of GnRH was higher than that of GnRH-R (P < 0.05). During the post-implantation stage, GnRH-R expression was significantly higher in uteroplacental than in interplacental tissues. In the uterus, GnRH-R stained strongly in the surface and glandular epithelial cells, and seemed to be weaker in myometrium and stroma. Placental signals were predominantly localized in fetal trophoblast cells and to a lesser extent in maternal decidual cells. These findings suggest a local regulatory function of GnRH during early canine pregnancy. (C) 2015 Elsevier Inc. All rights reserved.Öğe Is Apoptosis a Regulatory Mechanism During Early Canine Pregnancy?(Wiley-Blackwell, 2012) Schaefer-Somi, S.; Sabitzer, S.; Klein, D.; Tomaszewski, C.; Kanca, H.; Beceriklisoy, H. B.; Kucukaslan, I.Contents Fas is a membrane-bound protein which upon activation causes programmed cell death. Fas ligand (FasL) binds Fas on target cells. Both these factors are known to regulate apoptosis at implantation in different species and thus might be involved in the regulation of implantation in dogs. The aim of the study was to assess the expression of Fas and FasL in canine uterine tissue throughout pregnancy as well as in pre-implantation embryos using RT-PCR and RT-qPCR. Uterine tissues was collected from of 21 healthy pregnant bitches (group I: days 1012, n=5; group II: days 1825, n=6; group III: days 2845, n=6) and from 4 non-pregnant bitches (controls: days 1012). Pregnancy stage was determined by days after mating, that is, 23days after ovulation as determined by vaginal cytology and progesterone measurement. After ovariohysterectomy, uteri from group I bitches were flushed with PBS and the embryos washed and stored frozen at -80 degrees. Tissues from the other groups were taken from the implantation and placentation sites, respectively, covered with Tissue Tek (R) and frozen at -80 degrees. Extraction of RNA was performed with Trizol Reagent and RT-qPCR using SYBR green probes. In pre-implantation embryos, only FasL but not Fas could be detected. In all tissues from pregnant and non-pregnant bitches, both parameters were detectable. Before implantation (group I) expression of FasL resembled that of non-pregnant bitches in early dioestrus and decreased significantly during implantation and thereafter (p<0.05). Expression of Fas did not change significantly until day 45. The relative expression of Fas exceeded that of FasL at each stage investigated, which is comparable to observations of other species; however, high standard deviations indicate high individual differences. These preliminary results point towards a regulatory function of the Fas/FasL system during early canine pregnancy.Öğe Vascular Endothelial (VEGF) and Epidermal Growth Factor (EGF) as well as Platelet Activating Factor (PAF) and receptors are expressed in the early pregnant canine uterus(Wiley-Blackwell, 2012) Schaefer-Somi, S.; Sabitzer, S.; Klein, D.; Reinbacher, E.; Kanca, H.; Beceriklisoy, H. B.; Kucukaslan, I.[Abstract Not Available]
