Expression of GnRH, Kisspeptin, and Their Specific Receptors in the Ovary and Uterus in Deslorelin-Treated Late-Prepubertal Bitches.

In this study, the expression and localization of gonadotropin-releasing hormone (GnRH1) and kisspeptin (KISS1) and their specific receptors in canine ovarian and uterine tissues were investigated after the application of deslorelin acetate (Suprelorin, 4.7 mg, Virbac, France) in the late prepubertal period. We hypothesized that prolonged treatment of prepubertal dogs with deslorelin would alter the expression of GnRH and kisspeptin genes in the uterus and ovaries.

The effects of the activation of TLR2/TLR1 on in vitro angiogenesis in an immortalized ovine luteal endothelial cell line.

In Brief: Activation of TLR2/TLR1 alters in vitro formation of capillary-like structures and induces inflammatory processes in ovine luteal endothelial (OLENDO) cells.

Abstract: Postpartum bacterial infections of the uterus affect uterine physiology and ovarian activity, causing fertility problems. The outer membrane component of Gram-negative bacteria, lipopolysaccharide, is involved in the initiation of the local inflammatory processes, and other bacterial toxins, particularly lipopeptides, have also been shown to be potent cytokine inducers, acting via Toll-like receptor-2 (TLR2).

The effects of follicle stimulating hormone (FSH)-induced controlled ovarian hyperstimulation and nutrition on implantation-related gene expression in caruncular tissues of non-pregnant sheep.

Disturbances at the conceptus-maternal interface can have detrimental effects on pregnancy outcome. Additionally, changes in body condition and exogenously administered gonadotropins could affect ovarian and uterine function, including cell proliferation and ovulation rates, and alter endometrial receptivity. In ruminants, endometrial caruncles maintain placental function via interaction with fetal chorionic cotyledons.

The Efficacy of a 3β-Hydroxysteroid Dehydrogenase Inhibitor for the Termination of Mid-Term Pregnancies in Dogs.

Progesterone (P4) is the only hormone needed to maintain pregnancy in dogs. Therefore, a competitive inhibitor of 3β-hydroxysteroid dehydrogenase (3β-HSD) could be a safe and effective option to terminate pregnancy by inhibiting P4 synthesis. To address this hypothesis, we investigated the efficacy of trilostane (TRL), a competitive inhibitor of 3β-HSD, in terminating pregnancy in dogs.

Testicular Expression of Antioxidant Enzymes and Changes in Response to a Slow-Release Deslorelin Implant (Suprelorin 4.7 mg) in the Dog.

Spermatogenesis takes place in a hypoxic environment, and antioxidant enzymes protect germ and somatic cells from free radical-mediated damage. Expression of the antioxidant enzyme system in the canine testis has not yet been investigated. We hypothesized that the slow-release GnRH superagonist deslorelin 4.

Molecular Mechanisms of Lipopolysaccharide (LPS) Induced Inflammation in an Immortalized Ovine Luteal Endothelial Cell Line (OLENDO).

Escherichia coli (E. coli) is the most common Gram-negative bacterium causing infection of the uterus or mammary gland and is one of the major causes of infertility in livestock. In those animals affected by E.

Canine Endotheliochorial Placenta: Morpho-Functional Aspects.

In the domestic dog, placentation arises from central implantation, passing through a transitional, yet important stage of choriovitelline placenta (yolk sac placenta), on the way to the formation of the definite, deciduate, zonary (girdle) allantochorionic endotheliochorial placenta.Sharing some similarities with other invasive types of placentation, e.g.

Plane of nutrition and FSH-induced superovulation affect the expression of steroid hormone receptors and growth factors in caruncular tissue of non-pregnant sheep.

Implantation is a critical step in the establishment of pregnancy and an important part of embryo-maternal contact. Uterine receptivity can be affected by changes in body condition and the maternal endocrine milieu, including those caused by the use of exogenous gonadotropins in controlled ovarian hyperstimulation to induce the development of multiple follicles. This study demonstrates the effects of FSH-mediated ovarian hyperstimulation on the caruncles of ewes under various feeding regimes.

Anti-Müllerian hormone, testosterone, and insulin-like peptide 3 as biomarkers of Sertoli and Leydig cell function during deslorelin-induced testicular downregulation in the dog.

The role of anti-Müllerian hormone (AMH) and insulin-like peptide 3 (INSL3) in male infertility is not fully understood. We used the downregulated testis as a model of gonadotropin-dependent infertility. Serum testosterone and AMH concentrations were studied in five adult male Beagles implanted (day 0) with 4.

Implications of the RhoA/Rho associated kinase pathway and leptin in primary uterine inertia in the dog.

The underlying functional and molecular changes in canine primary uterine inertia (PUI) are still not clarified. Leptin (Lep) and obesity negatively affect uterine contractility in women, partly mediated by the RhoA/Rho associated kinase pathway, affecting myometrial calcium sensitization. We hypothesized that increased uterine Lep/Lep receptor (LepR) or decreased RhoA/Rho associated kinase expression contributes to PUI in dogs, independent of obesity.

Correction to: Canine Endotheliochorial Placenta: Morpho-Functional Aspects.

Chapter 8 was inadvertently published with errors and the following corrections were updated.

Progesterone receptor blockers: historical perspective, mode of function and insights into clinical and scientific applications.

Antigestagens (antiprogestins) are functional competitors of progesterone (P4) that prevent P4 from mediating its biological functions either by suppressing its production or blocking its function. Among the latter are progesterone antagonists, competitors of P4 binding to its nuclear receptor PGR, which have found application in both human and veterinary medicine, in particular in small animal practice for the prevention of nidation and the interruption of pregnancy. Depending on their mode of action, progesterone receptor antagonists can be divided into 2 classes.

Lipopolysaccharide disrupts gap junctional intercellular communication in an immortalized ovine luteal endothelial cell line.

Gram-negative bacteria, in particular Escherichia coli with its cell wall lipopolysaccharide (LPS), often cause metritis and mastitis in domestic animals. Ovarian LPS accumulation may initiate local inflammatory reactions mediated through cell surface Toll-like receptors (TLRs). This may disrupt ovarian functionality leading to infertility.

Prostaglandin-mediated effects in early canine corpus luteum: In vivo effects on vascular and immune factors.

Prostaglandins (PGs) are important regulators of the early corpus luteum (CL) in the dog. Whereas, initially, CL is gonadotropin independent, in the second half of its lifespan, hypophyseal support is required. The transition period is marked by decreased availability of PGs, in particular of PGE2.

Angiopoietin expression in ovine corpora lutea during the luteal phase: Effects of nutrition, arginine and follicle stimulating hormone.

The aim of this study was to evaluate angiopoietin (ANGPT) 1 and 2, and tyrosine-protein kinase receptor 2 (TIE2) expression in the corpora lutea (CL) of FSH-treated, or non-treated sheep administered arginine (Arg) or vehicle (saline, Sal), and fed a control (C), excess (O) or restricted (U) diet. Ewes from each dietary group were treated with Arg or Sal (experiment 1), and with FSH (experiment 2). Luteal tissues were collected at the early-, mid- and/or late-luteal phases of the estrous cycle.

Luteal ANGPT-TIE system during selected stages of pregnancy, and normal and antigestagen-induced luteolysis in the dog.

Rapid establishment of a vascular network is essential for normal functionality of the corpus luteum (CL). The early luteal phase is associated with increased expression of the VEGF system in canine CL. Acting in synchrony with angiopoietins (ANGPTs), VEGF system plays major roles in stabilization of blood vessels.

Transcriptome analysis reveals differences in mechanisms regulating cessation of luteal function in pregnant and non-pregnant dogs.

Background: In the domestic dog, corpora lutea (CL) are the only source of progesterone (P4), both in pregnant and non-pregnant cycles because there is no placental steroidogenesis. The absence of an endogenous luteolysin in absence of pregnancy results in long-lasting physiological pseudopregnancy, strongly contrasting with the acute luteolysis observed prepartum. The underlying biological mechanisms and the involvement of P4 signalling remain, however, not fully understood.

Functional implications of the utero-placental relaxin (RLN) system in the dog throughout pregnancy and at term.

Relaxin (RLN) is a key hormone of pregnancy in mammals best known for its involvement in connective tissue remodeling. In the domestic dog, placental RLN is the only known endocrine marker of pregnancy. However, knowledge is sparse regarding the spatio-temporal expression of RLN and its receptors (RXFP1 and RXFP2) in the canine uterus and placenta.

Uterine responses to early pre-attachment embryos in the domestic dog and comparisons with other domestic animal species.

In the dog, there is no luteolysis in the absence of pregnancy. Thus, this species lacks any anti-luteolytic endocrine signal as found in other species that modulate uterine function during the critical period of pregnancy establishment. Nevertheless, in the dog an embryo-maternal communication must occur in order to prevent rejection of embryos.

Cells expressing CD4, CD8, MHCII and endoglin in the canine corpus luteum of pregnancy, and prepartum activation of the luteal TNFα system.

In the dog, knowledge about involvement of the immune system in controlling luteal function is restricted to observations showing a time-dependent invasion of immune cells into the corpus luteum (CL) of non-pregnant bitches. Therefore, this study investigated the presence of CD4-, CD8-, MHCII- and endoglin-expressing cells in CL collected throughout pregnancy from pre-implantation until prepartum luteolysis. Immunohistochemistry and semi-quantitative RT-PCR were applied.

Cellular localization, expression and functional implications of the utero-placental endothelin system during maintenance and termination of canine gestation.

Utero-placental (Ut-Pl) angiogenesis and blood flow are fundamental for successful outcome of pregnancy. They are controlled by numerous vasodilator and vasoconstrictor systems such as endothelins (EDNs) and the renin angiotensin system. Dogs possess an invasive type of placentation, classified as endotheliochorial.

Elevated utero/placental GR/NR3C1 is not required for the induction of parturition in the dog.

The endocrine mechanisms that lead to initiation of parturition in dogs are still not fully understood. The prepartum luteolysis is associated with increased prostaglandin (PG) F2α secretion; however, there is no pregnancy- or parturition-related increase in estrogens. Moreover, unlike in other mammalian species, in the dog, increased peripartum levels of cortisol measured sporadically in maternal peripheral blood are not mandatory for normal parturition.

The Dog: Nonconformist, Not Only in Maternal Recognition Signaling.

Although similar at the molecular and cellular levels, endocrine mechanisms governing reproductive function in the domestic dog (Canis familiaris) differ markedly at the regulatory level from those known in other domestic animal species. Some of the events, e.g.

Expression and localization of vascular endothelial growth factor A (VEGFA) and its two receptors (VEGFR1/FLT1 and VEGFR2/FLK1/KDR) in the canine corpus luteum and utero-placental compartments during pregnancy and at normal and induced parturition.

VEGFA is one of the most potent known inducers of angiogenesis. However, the function of angiogenic factors in the canine corpus luteum (CL) of pregnancy and in the pregnant uterus and placenta has not yet been elucidated. Therefore, here we investigated the expression and localization of VEGFA and its receptors (VEGFR1/FLT1 and VEGFR2/FLK1/KDR) in the canine CL and utero-placental compartments (ut-pl) throughout pregnancy until prepartum luteolysis.

In vitro decidualisation of canine uterine stromal cells.

Background: The uterine response to the presence of embryos is poorly understood in the domestic dog (Canis familiaris). The intimate embryo-maternal cross-talk, which begins following the hatching of blastocysts and embryo attachment leads to strong structural and functional remodelling of the uterus. A part of this process is decidualisation, comprising morphological and biochemical changes that result in formation of maternal stroma-derived decidual cells.