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The Yale journal of biology and medicine2017; 90(3); 449-461;

A Brief Account of the Discovery of the Fetal/Placental Unit for Estrogen Production in Equine and Human Pregnancies: Relation to Human Medicine.

Abstract: The role of steroids in human medicine is well recognized, but the major contributions made by the large domestic animals as a source of material in the discovery, isolation, and determination of the structure of the steroid hormones is less well appreciated. After a brief reminder of the early efforts to obtain a reliable source of steroids for clinical use, the narrative here is to outline one example where success was ultimately achieved for estrogen replacement therapy. Whereas knowledge of the high concentrations of estrogens in urine of pregnant women and mares dates from the late 1920s, it was not until the 1940s that the latter was shown to be a practical source. Initially, the placenta was held to be responsible, but the involvement of the fetus in each case was eventually established. The remarkable enlargement of the human fetal adrenal glands and the fetal gonads in the horse, with characteristic features of steroid secreting tissues, suggested their participation. Ultimately, it was 16-hydroxylation by the fetal liver that resulted in estriol being the major estrogen type, by far, in late human pregnancy. In the mare, the pattern of estrogen production reflected that of the growth and later regression of the fetal gonads. The characteristic production ring-B, unsaturated estrogens in the mare is derived from an alternative pathway involving retention of the additional double bond in the biosynthesis of equilin.
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Publication Date: 2017-09-25 PubMed ID: 28955183PubMed Central: PMC5612187
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

The research article reviews the discovery and understanding that the fetal-placental unit in both equine and human pregnancy is a key source of estrogen production. It details the crucial role of large domestic animals in the history of steroid hormone research and highlights the importance of this biological process for estrogen replacement therapy in human medicine.

Background

  • The study sets the context by highlighting the importance of steroids in human medicine, specifically the role of steroid hormones.
  • It points out that the substantial contributions of large domestic animals in steroid hormone research and development are often overlooked.
  • The paper serves to outline an instance where breakthrough was achieved in estrogen replacement therapy, a vital aspect of human medicine.

Early Research and Significant Discoveries

  • The article mentions the recognition, from as early as the 1920s, of high estrogen concentrations in the urine of pregnant women and mares.
  • However, it wasn’t until the 1940s that the urine of pregnant mares was confirmed to be a practical source of estrogen.
  • Researchers initially thought the placenta was solely responsible for estrogen production, but shifting understandings eventually established that both the fetus and placenta are involved in this process.

Role of Human and Equine Fetal Tissues

  • The research recounts the discovery of the large size of the human fetal adrenal glands and horse fetal gonads, which suggested their involvement in steroid production.
  • The major estrogen type during late human pregnancy, estriol, was found to be a result of 16-hydroxylation by the fetal liver.
  • In mares, estrogen production was seen to correlate with the growth and later regression of the fetal gonads.

Understanding the Biochemical Processes

  • Notably, the research discusses the process through which the unique production ring-B, unsaturated estrogens in mares, is derived from an alternative pathway involving retention of the additional double bond in the synthesis of equilin, an estrogen hormone.

Impact of the Study

  • This research offers significant insights into the evolution of understanding estrogen production, mainly its source and process, and its application in human medicine for estrogen replacement therapy.

Cite This Article

APA
Raeside JI. (2017). A Brief Account of the Discovery of the Fetal/Placental Unit for Estrogen Production in Equine and Human Pregnancies: Relation to Human Medicine. Yale J Biol Med, 90(3), 449-461.

Publication

The Yale journal of biology and medicine
ISSN: 1551-4056
NlmUniqueID: 0417414
Country: United States
Language: English
Volume: 90
Issue: 3
Pages: 449-461

Researcher Affiliations

Raeside, James I
  • Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada.

MeSH Terms

  • Adrenal Glands / embryology
  • Adrenal Glands / metabolism
  • Animals
  • Estrogens / metabolism
  • Estrone / metabolism
  • Female
  • Gonads / embryology
  • Gonads / metabolism
  • Horses
  • Humans
  • Placenta / embryology
  • Placenta / metabolism
  • Pregnancy
  • Steroids / metabolism

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