Melatonin in sperm biology: breaking paradigms

Area of Science:

• Endocrinology
• Molecular Biology
• Reproductive Biology

Background:

• Melatonin is a ubiquitous molecule involved in numerous physiological functions across diverse organisms.
• It acts as a photoperiodic signal, influencing tissues with melatonin-binding sites in both central and peripheral nervous systems.
• Melatonin exhibits complex actions, crossing cell membranes to affect all body cells.

Purpose of the Study:

• To review recent advancements in understanding the physiological roles of melatonin and its associated receptors.
• To specifically examine the biological functions of melatonin in mammalian seasonal reproduction.
• To discuss the significance of melatonin's presence and concentration in seminal plasma.

Main Methods:

• This review synthesizes current research on melatonin's mechanisms of action.
• It analyzes findings related to melatonin's interaction with MT1 and MT2 G-protein-coupled receptors.
• The review also considers melatonin's binding to calmodulin and nuclear receptors (RORα1, RORα2, RZRβ).

Main Results:

• Melatonin's actions are mediated through various pathways, including GPCRs (MT1, MT2) and nuclear receptors.
• Specific roles in mammalian seasonal reproduction and the function of melatonin in spermatozoa are highlighted.
• The continuous presence of melatonin in seminal plasma suggests a significant, constant role.

Conclusions:

• Melatonin plays a crucial role in photoperiod signaling and reproductive physiology.
• Its diverse receptor interactions underscore its broad physiological impact.
• Further research into melatonin's specific functions in reproduction and seminal plasma is warranted.