PACAP: A regulator of mammalian reproductive function

Area of Science:

• Neuroendocrinology
• Reproductive Biology
• Molecular Endocrinology

Background:

• Pituitary adenylate cyclase-activating polypeptide (PACAP) is an ancestral peptide hormone.
• PACAP stimulates cAMP production and is involved in reproductive regulation alongside GnRH.
• PACAP exhibits widespread distribution, suggesting diverse physiological roles beyond a simple releasing factor.

Purpose of the Study:

• To review the expression and function of PACAP within the hypothalamic-pituitary-gonadal (HPG) axis.
• To emphasize PACAP's specific role in fetal and neonatal pituitary function.
• To consolidate current knowledge on PACAP's paracrine/autocrine regulatory functions.

Main Methods:

• Literature review of existing studies on PACAP.
• Analysis of PACAP expression patterns in the HPG axis.
• Synthesis of functional data regarding PACAP's impact on reproductive tissues and the pituitary.

Main Results:

• PACAP is widely expressed in the CNS, pituitary, gonads, and placenta.
• PACAP acts as a paracrine/autocrine regulator in various tissues.
• Evidence highlights PACAP's significant role in fetal and neonatal pituitary development and function.

Conclusions:

• PACAP is a crucial regulator within the HPG axis, extending beyond its initial identification.
• Its paracrine/autocrine actions are vital for reproductive control.
• PACAP plays a critical role in the developing pituitary, particularly in fetuses and newborns.