Steroids in the follicular fluid and the corpus luteum of the mare. A ‘two-cell type’ theory of ovarian steroid synthesis.
Abstract: A comparison has been made between the steroids present in equine follicular fluid and luteal tissue. Follicular fluid was found to contain progesterone, 17α-hydroxyprogesterone, androstenedione, epitestosterone, 19-norandrostenedione, oestrone, oestradiol-17β and 6α-hydroxyoestradiol-17β, in confirmation of previous studies. On the other hand, luteal tissue contained large amounts of progesterone and 20α-hydroxypregn-4-en-3-one, and a small quantity of 17α-hydroxyprogesterone. No C18 or C19 steroids could be detected.
These findings are therefore interpreted as evidence in favour of a 'two-cell type' theory of steroid formation in the ovary. One type, possibly the theca interna cell, has the ability to convert progesterone into oestrogens; the other type, possibly the luteinized granulosa cell, has a diminished 17-hydroxylating ability and is unable to cleave the C21 side chain to make C18 and C19 steroids. However, it does have an active 20-reductase enzyme system present.
Publication Date: 1962-03-01 PubMed ID: 13912279DOI: 10.1677/joe.0.0240059Google Scholar: Lookup
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Summary
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This research focuses on analyzing the types and amounts of steroids present in two parts of a horse’s ovary — the follicular fluid and the luteal tissue — comparing their contents, and suggesting a ‘two-cell type’ theory for ovarian steroid synthesis.
Overview of the Research
- The research involved comparing the types of steroids present in equine (horse) follicular fluid and luteal tissue. These are parts of the ovary involved in the egg development and hormone release.
- Various sorts of steroids including progesterone, 17α-hydroxyprogesterone, androstenedione, epitestosterone, 19-norandrostenedione, oestrone, oestradiol-17β and 6α-hydroxyoestradiol-17β were found in follicular fluid.
- Contrarily, luteal tissue contained more concentrated amounts of progesterone and the steroid hormone 20α-hydroxypregn-4-en-3-one, and small amounts of 17α-hydroxyprogesterone but none of the C18 or C19 steroids, which are other types of steroid hormones.
The ‘Two-Cell Type’ Theory
- Based on the comparison, the research proposed a ‘two-cell type’ theory for how steroids are formed in the ovary.
- The proposed theory states there are two distinct kinds of cells involved in the process.
- The first type, which could be the theca interna cell, is capable of transforming progesterone into oestrogens (a group of hormones that regulate female sexual and reproductive development).
- The other type, potentially the luteinized granulosa cell, has a reduced capacity to perform a process known as 17-hydroxylation and is unable to cleave (split) the C21 side chain to produce C18 and C19 steroids. However, this cell type does possess an active 20-reductase enzyme system.
- 20-reductase enzyme system is essential for proper function of the cells and may play a role in hormone synthesis.
Significance of the Study
- This study broadens the understanding of ovarian steroidal hormone synthesis which could have an impact on the reproductive health of horses. As such, it could influence strategies for breeding and managing the reproductive health of horses.
- Furthermore, the ‘two-cell type’ theory proposed in the research could lead to further studies not only applicable to equine species but potentially providing insights into the steroid synthesis procedures in other species, including humans.
Cite This Article
APA
SHORT RV.
(1962).
Steroids in the follicular fluid and the corpus luteum of the mare. A ‘two-cell type’ theory of ovarian steroid synthesis.
J Endocrinol, 24, 59-63.
https://doi.org/10.1677/joe.0.0240059 Publication
Researcher Affiliations
MeSH Terms
- Animals
- Corpus Luteum
- Corpus Luteum Hormones
- Female
- Follicular Fluid
- Horses
- Humans
- Ovarian Follicle / chemistry
- Steroids
Citations
This article has been cited 10 times.- Nagashima JB, Hill AM, Songsasen N. In vitro development of mechanically and enzymatically isolated cat ovarian follicles.. Reprod Fertil 2021;2(1):35-46.
- Schiffer L, Barnard L, Baranowski ES, Gilligan LC, Taylor AE, Arlt W, Shackleton CHL, Storbeck KH. Human steroid biosynthesis, metabolism and excretion are differentially reflected by serum and urine steroid metabolomes: A comprehensive review.. J Steroid Biochem Mol Biol 2019 Nov;194:105439.
- Mochtar MH, Danhof NA, Ayeleke RO, Van der Veen F, van Wely M. Recombinant luteinizing hormone (rLH) and recombinant follicle stimulating hormone (rFSH) for ovarian stimulation in IVF/ICSI cycles.. Cochrane Database Syst Rev 2017 May 24;5(5):CD005070.
- Wright RS, Zhao WX. Steroid release from separated theca and granulosa layers of Atlantic salmon (Salmo salar) ovarian follicles: the effects of a purified salmon gonadotrophin preparation.. Fish Physiol Biochem 1988 Jul;5(3):131-9.
- Tingen CM, Kiesewetter SE, Jozefik J, Thomas C, Tagler D, Shea L, Woodruff TK. A macrophage and theca cell-enriched stromal cell population influences growth and survival of immature murine follicles in vitro.. Reproduction 2011 Jun;141(6):809-20.
- CROOKE AC, BUTT WR, PALMER R, MORRIS R, EDWARDS RL, TAYLOR CW, SHORT RV. Effect of human pituitaryfollicle-stimulating hormone and chorionic vonadotrophin in Stein-Leventhal syndrome.. Br Med J 1963 Apr 27;1(5338):1119-23.
- Bettendorf G. [Ovulation, its physiology and induction by drugs].. Arch Gynakol 1965;202:132-59.
- Blumenfeld Z. Growth hormone--a cogonadotropin? Its role in ovulation induction.. J In Vitro Fert Embryo Transf 1991 Jun;8(3):127-36.
- Mestwerdt W, Müller O, Brandau H. [Light and electronmicroscopic examinations on granulosa and theca of preovulatory and freshly ruptured follicles of human ovaries (author's transl)].. Arch Gynakol 1977 Mar 31;222(2):115-36.
- Zoller LC, Weisz J. A quantitative cytochemical study of glucose-6-phosphate dehydrogenase and delta 5-3 beta-hydroxysteroid dehydrogenase activity in the membrana granulosa of the ovulable type of follicle of the rat.. Histochemistry 1979 Aug;62(2):125-35.
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