The ovarian endothelin network: an evolving story.
1Department of Animal Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, Rehovot 76100, Israel. rina.meidan@huji.ac.il
Trends in Endocrinology and Metabolism: TEM
|November 13, 2007
Summary
The ovarian endothelin (ET) system, including ET isopeptides and receptors, influences key reproductive functions like ovulation. Understanding this network offers new reproductive control strategies.
Area of Science:
- Reproductive biology
- Endocrinology
- Molecular signaling
Background:
- The endothelin (ET) system comprises ET isopeptides, converting enzymes, and ETA/ETB receptors.
- The ovarian ET network has rapidly expanded since ET-1's discovery in granulosa cells.
Purpose of the Study:
- To review current findings on the ovarian ET network.
- To highlight the role of ETs in reproductive processes.
Main Methods:
- Literature review of recent studies on the ovarian ET system.
- Synthesis of data on ET isopeptides, enzymes, and receptors in the ovary.
Main Results:
- ETs significantly impact ovulation, steroidogenesis, and luteolysis.
- New members and functions within the ovarian ET network are continually being discovered.
Conclusions:
- A comprehensive understanding of the ovarian ET network is crucial.
- This knowledge may lead to novel strategies for reproductive management.
More Related Videos
Related Concept Videos
Regulation of Angiogenesis and Blood Supply
Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...
Mechanism of Angiogenesis
Blood vessel formation starts early during embryonic development, around day 7. In the extraembryonic yolk sac, mesodermal precursor cells called hemangioblast proliferate and differentiate into angioblast. Angioblasts express vascular endothelial growth factor receptor 2 or VEGFR2, which binds VEGF-A, a proangiogenic factor, guiding blood vessel formation. VEGF signaling promotes angioblasts to form a blood island in the developing embryo. Angioblasts further differentiate, giving rise to...
Hormonal Control of the Ovarian Cycle
The ovarian cycle is meticulously regulated by the hypothalamic-pituitary-gonadal axis. This cycle orchestrates the release of a mature oocyte, essential for reproduction.
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
Endocrine Signaling
Endocrine cells produce hormones to communicate with remote target cells found in other organs. The hormone reaches these distant areas using the circulatory system. This exposes the whole organism to the hormone but only those cells expressing hormone receptors or target cells are affected. Thus, endocrine signaling induces slow responses from its target cells but these effects also last longer.
Endocrine Signaling
Endocrine cells produce hormones to communicate with remote target cells found in other organs. The hormone reaches these distant areas using the circulatory system. This exposes the whole organism to the hormone but only those cells expressing hormone receptors or target cells are affected. Thus, endocrine signaling induces slow responses from its target cells but these effects also last longer.
Oogenesis
In human women, oogenesis produces one mature egg cell or ovum for every precursor cell that enters meiosis. This process differs in two unique ways from the equivalent procedure of spermatogenesis in males. First, meiotic divisions during oogenesis are asymmetric, meaning that a large oocyte (containing most of the cytoplasm) and minor polar body are produced as a result of meiosis I, and again following meiosis II. Since only oocytes will go on to form embryos if fertilized, this unequal...


