NAD+-dependent 15-hydroxyprostaglandin dehydrogenase activity in human endometrium

Area of Science:

• Reproductive biology
• Enzymology
• Endocrinology

Background:

• Prostaglandins play crucial roles in reproductive processes, including menstruation and implantation.
• NAD+-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is a key enzyme in prostaglandin metabolism.
• Understanding 15-PGDH activity in the human endometrium is important for reproductive health.

Purpose of the Study:

• To measure the specific activity of NAD+-dependent 15-hydroxyprostaglandin dehydrogenase in human endometrial tissue.
• To investigate the relationship between 15-PGDH activity and the menstrual cycle phases in ovulatory women.
• To compare 15-PGDH activity in the endometrium of ovulatory and anovulatory women.

Main Methods:

• Human endometrial tissue samples were obtained from ovulatory and anovulatory women.
• The specific activity of NAD+-dependent 15-hydroxyprostaglandin dehydrogenase was assayed using PGE2 as a substrate.
• Endometrial tissue was fractionated to isolate cytosolic components, and glandular epithelium was separated from stromal cells.

Main Results:

• 15-hydroxyprostaglandin dehydrogenase specific activity was highest during the secretory phase (days 15-25) and lowest during the menstrual (days 1-5) and premenstrual (days 26-28) phases in ovulatory women.
• In anovulatory women, 15-PGDH activity was low, comparable to the proliferative phase (days 6-14) of ovulatory women.
• The enzyme activity was localized to the cytosolic fraction and primarily found in the glandular epithelium.

Conclusions:

• NAD+-dependent 15-hydroxyprostaglandin dehydrogenase activity in the human endometrium exhibits distinct cyclical patterns.
• Altered 15-PGDH activity may be associated with anovulatory conditions.
• The glandular epithelium is the principal site of prostaglandin metabolism by 15-PGDH in the endometrium.