[Relaxin in ovarian follicles]

Area of Science:

• Endocrinology
• Reproductive Biology
• Molecular Endocrinology

Background:

• Relaxin (RLN) is a peptide hormone structurally related to insulin.
• Initial understanding of RLN focused on its reproductive roles, particularly in the pubic symphysis and uterus.
• Recent advancements include the synthesis of human relaxin and the discovery of its broader biological activities.

Purpose of the Study:

• To review the evolving knowledge of relaxin's chemistry and biological properties.
• To highlight newly identified functions and production sites of relaxin.
• To present immunohistochemical findings on relaxin-like substances in ovarian granulosa cells.

Main Methods:

• Extraction and purification of porcine relaxin.
• Application of radio-immunological and immunohistochemical methods.
• In vitro studies on porcine granulosa cells.
• Immunohistochemical analysis of human and porcine ovarian follicles.

Main Results:

• Relaxin exhibits diverse biological activities beyond its established reproductive functions.
• New production sites identified include the ovary, mammary gland, seminal plasma, decidua, endometrial glands, and prostatic gland.
• Immunohistochemistry confirmed relaxin-like substances in granulosa cells of human and porcine ovarian follicles, suggesting potential local production.

Conclusions:

• The scope of relaxin's biological actions and production sites is significantly broader than previously understood.
• Relaxin's presence in ovarian follicular fluid and granulosa cells indicates a potential role in ovarian function.
• Further research is warranted to elucidate the full spectrum of relaxin's physiological and pathophysiological roles.