Effects of Estradiol-17.BETA. on Oxytocin and Progesterone Release of the Bovine Corpus Luteum during the Estrous Cycle.

Liebermann, Jürgen; Schams, D.

doi:10.1262/jrd.41.187

Cited by 7 publications

(3 citation statements)

References 37 publications

(35 reference statements)

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“…In in vitro MDS studies, E 2 perfusion of bovine CL from different luteal stages with different doses shifted from no effect (d 5-7 and 8-12) to an inhibitory effect (d 15-18) on P secretion during the estrous cycle. E 2 at all doses tested was most stimulative on the release of oxytocin during d 5-7 but continuously inhibited oxytocin release from the middle to late luteal phase of the estrous cycle (48). In a recent in vitro study, E inhibited P production by bovine luteal cells in a dose-dependent manner (49).…”

Section: Discussionmentioning

confidence: 82%

Expression of Estrogen and Progesterone Receptors in the Bovine Ovary During Estrous Cycle and Pregnancy

Berisha¹,

Pfaffl²,

Schams³

2002

ENDO

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Section: Discussionmentioning

confidence: 82%

Expression of Estrogen and Progesterone Receptors in the Bovine Ovary During Estrous Cycle and Pregnancy

Berisha¹,

Pfaffl²,

Schams³

2002

ENDO

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“…2001). Estradiol‐17 β acts directly and acutely on the secretory function of bovine CL in an in vitro microdialysis system during the early luteal stage (days 5–7) of the oestrous cycle (Liebermann and Schams 1995). The PGF2 α seems to regulate the functionality of OT receptors.…”

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confidence: 99%

Regulation of Corpus Luteum Function in Cattle – an Overview

Schams

Berisha

2004

Reprod Domestic Animals

209

147

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The corpus luteum (CL) is a transient reproductive gland that produces progesterone (P), required for the establishment and maintenance of pregnancy. Although the regulation of bovine luteal function has been studied for several decades, many of the regulatory mechanisms involved are incompletely understood. We are far from understanding how these complex mechanisms function in unison. The purpose of this overview is to stress important steps of regulation during the lifetime of CL. In the first part, the importance and regulation of angiogenesis and blood flow during CL formation is described. The results underline the importance of growth factors especially of vascular endothelial growth factor A (VEGF A) and basic fibroblast growth factor (FGF-2) for development and completion of a dense network of capillaries. In the second part, the regulation of function by endocrine/paracrine- and autocrine-acting regulators is discussed. There is now more evidence that besides the main endocrine hormones LH and GH local regulators as growth factors, peptides, steroids and prostaglandins are important modulators of luteal function. During early CL development until mid-luteal stage oxytocin, prostaglandins and P itself stimulate luteal cell proliferation and function supported by the luteotropic action of a number of growth factors. The still high mRNA expression, protein concentration and localization of growth factors [VEGF, FGF-1, FGF-2, insulin-like growth factors (IGFs)] in the cytoplasm of luteal cells during mid-luteal stage suggest maintenance (survival) functions for growth factors. In the absence of pregnancy regression (luteolysis) of CL occurs. Progesterone itself regulates the length of the oestrous cycle by influencing the timing of the luteolytic signal prostaglandin F2alpha (PGF2alpha) from the endometrium. The cascade of mediators afterwards is very complex and still not well-elucidated. Evidence is given for participation of blood flow, inflammatory cytokines, vasoactive peptides (angiotensin II and endothelin-1), reactive oxygen species, angiogenic growth factors (VEGFs, FGFs, IGFs) and decrease of the classical luteotropic components as LH-R, GH-R, P450(scc) and 3beta-HSD. Despite of differences in methodology and interpretations, progress has been made and will continue to be made.

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“…Moreover, the human [6], rat [7], porcine [8], and bovine CL [9] produce estradiol-17β (E 2 ). E 2 affects the secretory function of cultured bovine luteal cells [10] and the microdialyzed bovine CL in vitro [11]. Since estrogen receptors are present in the bovine CL [12], luteal E 2 and exogenous estrogens may play…”

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confidence: 99%

Phytoestrogens and Their Metabolites Inhibit the Sensitivity of the Bovine Corpus Luteum to Luteotropic Factors

et al. 2006

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Abstract. The aim of this study was to examine whether active metabolites of phytoestrogens (equol and para-ethyl-phenol) inhibit sensitivity of bovine corpus luteum (CL) to luteinizing hormone (LH) and to auto/paracrine luteotropic factors (prostaglandin E2-PGE2 and prostaglandin F2α-PGF2α), and whether they influence pulsatile progesterone (P4) secretion by the bovine CL. In in vivo experiments, high levels of equol and para-ethyl-phenol were found in plasma and in the CL tissue of heifers and cows fed a soy bean diet (2.5 kg/animal/day), along with lower concentrations of P4 (P<0.05). Both Prostaglandins (PG) and LH strongly stimulated P4 secretion in cultured pieces of CL that were collected from cows fed a standard diet (P<0.01). There was no effect of PGs and LH on P4 stimulation in CLs obtained from cows fed a diet rich in soy bean. Finally, we examined whether active metabolites of phytoestrogens participated in regulation of pulsatile P4 secretion and LH-stimulated P4 secretion in vitro using a microdialysis system. Equol and para-ethyl-phenol had no effect on basic and pulsatile P4 secretion in CLs during 240 min of perfusion when compared to the control (P<0.05). However, they inhibited LH-stimulated P4 secretion (P<0.05). Phytoestrogens and their metabolites may disrupt CL function by inhibiting PG-and LH-stimulated P4 secretion. Key words: Phytoestrogens, Luteinizing hormone, Progesterone, Corpus luteum, Estrous cycle (J. Reprod. Dev. 52: [33][34][35][36][37][38][39][40][41] 2006) he corpus luteum (CL) is a reproductive gland that plays a role in regulation of the estrous cycle, fertility, and pregnancy [1]. The main function of the CL is secretion of progesterone (P 4 ), an important hormone for establishment of a successful pregnancy [2]. P 4 is secreted episodically from the bovine CL [3], and luteinizing hormone (LH) is one of the most potent regulators of synthesis and P 4 secretion from the bovine CL [4].The mechanisms controlling development, maintenance of the CL, and P 4 secretion involve many factors produced both, inside and outside the CL [1,5]. Besides pituitary hormones (LH and FSH), locally produced growth factors, peptides, steroids, and prostaglandins (PG) play important roles in bovine luteal function [1,4,5]. Moreover, the human [6], rat [7], porcine [8], and bovine CL [9] produce estradiol-17β (E 2 ). E 2 affects the secretory function of cultured bovine luteal cells [10] and the microdialyzed bovine CL in vitro [11]. Since estrogen receptors are present in the bovine CL [12], luteal E 2 and exogenous estrogens may play

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Effects of Estradiol-17.BETA. on Oxytocin and Progesterone Release of the Bovine Corpus Luteum during the Estrous Cycle.

Cited by 7 publications

References 37 publications

Expression of Estrogen and Progesterone Receptors in the Bovine Ovary During Estrous Cycle and Pregnancy

Expression of Estrogen and Progesterone Receptors in the Bovine Ovary During Estrous Cycle and Pregnancy

Regulation of Corpus Luteum Function in Cattle – an Overview

Phytoestrogens and Their Metabolites Inhibit the Sensitivity of the Bovine Corpus Luteum to Luteotropic Factors

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