Pituitary hormones in the brain: what is their function?

Area of Science:

• Neuroendocrinology
• Molecular Psychiatry

Background:

• Anterior and intermediate pituitary lobe hormones, including ACTH, beta-lipotropin, alpha-MSH, beta-endorphin, prolactin, growth hormone, gonadotrophic hormone, and TSH, have been detected in the central nervous system (CNS).
• The ACTH-lipotropin family of peptides shows evidence of synthesis occurring in both the brain and the pituitary gland.

Purpose of the Study:

• To review existing data on the presence and potential synthesis of anterior and intermediate lobe hormones within the CNS.
• To highlight the current gaps in understanding the physiological roles, mechanisms of action, biosynthesis, and regulation of these neuroactive peptides.

Main Methods:

• Literature review of studies investigating the presence and effects of pituitary hormones in the CNS.
• Analysis of evidence for peptide synthesis in both brain and pituitary tissues.
• Examination of reported behavioral effects of specific peptides and their fragments.

Main Results:

• Data confirm the presence of various anterior and intermediate lobe hormones within the CNS.
• Evidence suggests that peptides of the ACTH-lipotropin family can be synthesized within the brain.
• Behavioral effects have been documented for certain peptides (e.g., ACTH, alpha-MSH, beta-endorphin, prolactin) and their fragments.

Conclusions:

• The brain is a site for the synthesis of certain pituitary hormones, particularly the ACTH-lipotropin family.
• While behavioral effects are noted, the physiological significance, underlying mechanisms, biosynthetic pathways, and regulatory factors for these brain-derived peptides require extensive further investigation.