Localisation of 15-hydroxy prostaglandin dehydrogenase (PGDH) and steroidogenic enzymes in the equine placenta.

This study investigates the location of the enzymes 15-hydroxy prostaglandin dehydrogenase (PGDH) and certain steroidogenic enzymes in the horse placenta. The researchers gathered placental tissues from both pony and Thoroughbred mares during various stages of pregnancy, and used specific antibodies and visualization techniques to identify the presence and location of these enzymes.

Study Overview and Objective

• The main aim of this research was to determine how the enzyme 15-hydroxy prostaglandin dehydrogenase (PGDH) is regulated and where it alongside steroidogenic enzymes are located in the equine placenta. The PGDH enzyme is essential in controlling the metabolism of primary prostaglandins – hormone-like substances playing critical roles in various physiological functions.
• The researchers also wanted to investigate whether the regulation of PGDH occurs in a autocrine, paracrine, or intracrine manner. These terms describe how cells communicate, with autocrine signaling relating to a cell affecting itself, paracrine signaling being the communication between nearby cells, and intracrine signaling involving intracellular actions.

Methodology Employed

• Data was gathered from equine placental tissue samples from pony or Thoroughbred mares at around Days 150, 250-280, and more than 300 of pregnancy.
• Specialized techniques such as immunohistochemistry (a method that uses antibodies to detect specific proteins in cells or tissues) were used to localize key steroidogenic enzymes.
• The enzymes PGDH, 3beta-HSD, cholesterol side chain cleavage enzyme (P450scc) and 17-hydroxylase/lyase (P450C17) were localized using specific antibodies. These enzymes play key roles in the production and breakdown of steroid hormones.

Findings of the Study

• The researchers found IR-P450scc in trophoblast cells of the placenta but not in the maternal tissues retreived. Trophoblast cells help form the placenta, which is crucial during pregnancy for nutrient exchange between the mother and fetus.
• Contrastingly, the enzyme IR-PGDH was found in maternal epithelial and interstitial cells during Days 150 and 280 of pregnancy, but it was not detected in the trophoblasts or other placental cells. Epithelial and interstitial cells are types of cells found in tissues and organs.
• After Day 300, the enzyme IR-PGDH was not just present in the maternal epithelium and interstitial cells but also in the trophoblast cells of some specimens.