Home About us Contact
|
Home About us Contact | ||
|
|
||
Pregnant Bitches (pregnant + bitch)
Selected AbstractsExpression of MHC-I and -II in Uterine Tissue from Early Pregnant BitchesREPRODUCTION IN DOMESTIC ANIMALS, Issue 2009S Schäfer-Somi Contents The aim of the study was to investigate the expression of major histocompatibility complex (MHC)-I and -II in uterine tissues from pregnant and non-pregnant bitches, taken at different time periods after mating. The pregnant bitches were ovariohysterectomized during the pre-implantation (group 1, n = 4), implantation (group 2, n = 7) and placentation stage (group 3, n = 7). Non-pregnant animals in diestrus served as controls (group 4, n = 7). The expression of MHC- I and -II in salpinx, apex, middle horn, corpus uteri and at implantation sites was investigated by immunohistochemistry as well as qualitative and quantitative RT-PCR; MHC-I mRNA was detected in all tissues and with quantitative RT-PCR, and no significant changes were detected until placentation. Immunohistologically, at the apex and corpus site, the average number of MHC-II positive cells increased from the pre-implantation to the post-implantation stage (apex: 1.54 ± 1.21 to 3.82 ± 2.93; corpus: 1.62 ± 1.9 to 5.04 ± 4.95; p < 0.05). The greatest numbers of MHC-II positive cells were observed at placentation sites (6.64 ± 5.9). In parallel, a marked increase in the relative mRNA expression of MHC-II in uterine tissues was assessed from the pre-implantation to the placentation stage (relative to Glycerinaldehyd-3-phosphate-Dehydrogenase (GAPDH): 6.9 ± 9.5, 8.4 ± 5.8, p > 0.05). Immunohistologically, in the salpinx, significantly greater numbers of MHC-II positive cells were found in the tissues of pregnant animals than in the control group (p < 0.05). It is proposed that the increase in MHC-II is pregnancy-related, even though the impact on maintenance of canine pregnancy is still unclear. [source] Determination of gestational age in medium and small size bitches using ultrasonographic fetal measurementsJOURNAL OF SMALL ANIMAL PRACTICE, Issue 7 2000G. C. Luvoni A study was undertaken to estimate gestational age, in terms of days from parturition, in medium and small size dogs by ultrasonographic examination. Serial ultrasonographic examinations were performed in four medium size pregnant bitches throughout two consecutive pregnancies and three small size pregnant bitches throughout one pregnancy, in order to determine the range of variation in the size of selected fetal structures throughout gestation. Formulae were derived to estimate the expected delivery date for both groups of bitches by measuring anatomical fetal structures, so that this method could be applied to a large number of different breeds. The determination of gestational age could be achieved with reasonable precision by selecting fetal structures. Prediction of parturition date was accurate to within one day by ultrasonographic measurement of the diameter of the gestational sac in early pregnancy and the biparietal diameter in late pregnancy in both small size breeds and medium size breeds. [source] Comparison of Selected Endocrine Parameters During Luteal Phase and Pregnancy in German Shepherd Dogs and BeaglesREPRODUCTION IN DOMESTIC ANIMALS, Issue 2009AR Günzel-Apel Contents Concentrations of progesterone, prolactin and relaxin in serum at predetermined intervals after ovulation (day 0) in non-pregnant and pregnant normocyclic Beagles were assayed and results compared with those observed in German Shepherd dogs (GSD) in a previous study. The goal was to determine possible reproductive hormone specificities related to the GSD breed. Furthermore, the effects of medroxyprogesterone acetate (MPA)-treatment in non-pregnant Beagles and of progesterone supplementation in pregnant Beagles on the hormone concentrations were examined. Mean concentrations of progesterone and prolactin were not different in the non-pregnant Beagles compared with those seen in non-pregnant GSD, except at days 50,60, when progesterone concentrations were found to be higher in Beagles (p < 0.05). Mean progesterone concentrations in pregnant Beagles at days 50,60 after ovulation (day 0) were higher (p < 0.05) than in GSD at that time, but not at earlier time periods. Prolactin concentrations were higher (p < 0.05) in Beagles throughout pregnancy compared with those in the GSD. Mean relaxin concentrations were numerically but not significantly lower in GSD than in Beagles throughout pregnancy. A 10-day oral MPA treatment did not affect progesterone or prolactin secretion in normocyclic non-pregnant Beagles. Medroxyprogesterone acetate serum concentrations were approximately 3.9 ng/ml during treatment and decreased to 0.42 and 0.021 ng/ml within 5 and 15 days after end of treatment, respectively. Intramuscular progesterone supplementation from days 30 to 40 in pregnant Beagles resulted in higher concentrations of progesterone in the 36- to 45-day time periods; prolactin and relaxin concentrations were not significantly affected during or after treatment compared with administration of placebo. The results suggest a tendency towards deficient luteal function in the short-cycle GSD bitches previously studied, which in pregnancy may reflect the observed decreased prolactin concentrations; the possibility that GSD relaxin secretion is deficiency required needs further study. As oral treatment with MPA did not affect progesterone and prolactin release, it may be useful for studying luteal function in pregnant bitches with suspected hypoluteoidism. [source] Uterine Progesterone Receptor and Leukaemia Inhibitory Factor mRNA Expression in Canine PregnancyREPRODUCTION IN DOMESTIC ANIMALS, Issue 2009S Schäfer-Somi Contents The study investigated the expression of genes for progesterone receptor (PR) and for the cytokine leukaemia inhibitory factor (LIF) in the uterine tube and uterine horn tissues from pregnant and non-pregnant bitches. The aim was to study whether a relation existed between the likely biological effectiveness of progesterone (P4) and the change in the uterine expression of LIF mRNA during pregnancy, as has been described in primates. For this purpose, 20 pregnant bitches were ovariohysterectomized after being allotted to three groups according to gestational age (pre-implantation: days 10 to 12, n = 7; peri-implantation: days 18 to 25, n = 7; post-placentation: days 28 to 45, n = 7). Tissue samples were obtained from the uterine tubes, one uterine horn (including placentation sites and interplacental sites in bitches that had already implanted) and the corpus uteri, stored at ,80°C, and then analysed by qualitative and quantitative PCR for PR and LIF mRNA expression. From the pre-implantation to the placentation stage, a decrease in the relative expression of PR mRNA in uterine tissue was obvious and significant when expressed relative to ,-actin (11.2 ± 6.8 vs 2.7 ± 1.9; p < 0.05). However, over the same period, the relative expression of LIF mRNA increased (10.1 ± 16.1 vs 50.0 ± 32.3; p < 0.05). In addition, PR mRNA went from being detectable to no longer detectable in the uterine tube, and no longer detectable in interplacental-site uterine tissue. We conclude that LIF is important for the establishment of canine pregnancy; that decreased uterine PR mRNA expression may contribute to the increase in uterine LIF mRNA; and, that the ability of the embryo to preserve PR mRNA expression at implantation and placentation sites while expression is lost in the remainder of the uterus represent an effect important to the establishment and maintenance of pregnancy. We additionally propose that canine embryo secretory proteins have a regulatory effect on both PR and LIF before as well as at and after implantation. [source] Expression of Genes in the Canine Pre-implantation Uterus and Embryo: Implications for an Active Role of the Embryo Before and During InvasionREPRODUCTION IN DOMESTIC ANIMALS, Issue 6 2008S Schäfer-Somi Contents The aim of the present study was to assess genes expressed in maternal uterine tissue and pre-implantation embryos which are presumably involved in maternal recognition and establishment of canine pregnancy. For this purpose, 10 pregnant bitches were ovariohysterectomized between days 10 and 12 after mating. Four non-pregnant bitches served as controls. Early pregnancy was verified by flushing the uterine horns with PBS solution. The collected embryos (n = 60) were stored deep-frozen (,80°C). Uterine tissue was excised, snaps frozen in liquid nitrogen and homogenized using TRI Reagent. All embryos from one litter were thawed together and also homogenized in TRI Reagent. RT-PCR was performed to prove mRNA expression of progesterone receptor, key enzymes of the prostaglandin synthesis pathway, selected growth factors, cytokines, immune cell receptors, major histocompatibility complex (MHC) and matrix-metalloproteinases (MMP). Only pregnant uteri revealed the presence of mRNA for interferon (IFN)-,, IL-4 and CD-8, which resembles the milieu in humans and other mammalians. Similarly, in day 10 embryos, mRNA for transforming growth factor-,, insulin-like growth factor-1,-2, hepatocyte growth factor, leukaemia inhibitor factor, tumour necrosis factor-,, interleukin-1,,-6,-8, cyclooxygenase-2, CD4+ cells, and MMP-2 and -9 were detected, but not MHC-I or -II. We therefore suppose that the canine embryo, like its human counterpart, actively initiates measures to prevent attacks from the maternal immune system to prepare its own adhesion, nidation, growth and further development. [source] Secretion of Prolactin and Growth Hormone in Relation to Ovarian Activity in the DogREPRODUCTION IN DOMESTIC ANIMALS, Issue 3-4 2001HS Kooistra In pregnant bitches an apparent increase in plasma prolactin concentrations is observed during the second half of pregnancy, mean plasma prolactin concentrations peak on the day of parturition, fall for the next 24,48 h and then rise again. During lactation, high plasma prolactin concentrations are observed. Plasma prolactin levels in non-pregnant bitches appear to be lower than in pregnant animals, particularly in the last part of the luteal phase. Pulsatile secretion of prolactin has been observed during the luteal phase and mid-anoestrus. Progression of the luteal phase is found to be associated with an increase in prolactin release. The association of a strong increase of prolactin release and a decrease of plasma progesterone concentrations has also been demonstrated in overtly pseudopregnant bitches. Elevated prolactin secretion during progression of the luteal phase in the bitch may play a role in mammogenesis and is important because of the luteotrophic action of prolactin. Acromegaly is a syndrome of tissue overgrowth and insulin resistance due to excessive growth hormone (GH) production. In the bitch, acromegaly can be induced either by endogenous progesterone or by exogenous progestagens. Progestagen-induced GH production in this species originates from foci of hyperplastic ductular epithelium of the mammary gland. Pulsatile secretion of GH has been observed in normal cyclic bitches. In contrast with the pulsatile GH secretion seen in healthy dogs, the progestagen-induced plasma GH levels in bitches with acromegaly do not have a pulsatile secretion pattern. Just as with prolactin, the plasma progesterone levels influence the secretion pattern of GH in the bitch. The pulsatile secretion pattern of GH changes during the progression of the luteal phase in healthy cyclic bitches, with higher basal GH secretion and less GH being secreted in pulses during the first part of the luteal phase. The progesterone-induced GH production may promote the proliferation and differentiation of mammary gland tissue during the luteal phase of the bitch by local autocrine/paracrine effects and may exert endocrine effects. [source] | ||||||||||