Production

• corticotrope cells of the anterior pituitary gland
• melanotrope cells of the intermediate lobe of the pituitary gland
• about 3000 neurons in the arcuate nucleus of the hypothalamus
• smaller populations of neurons in the dorsomedial hypothalamus and brainstem
• melanocytes in the skin

Derivatives

• adrenocorticotropic hormone (ACTH) and β-LPH in the anterior pituitary gland
• CLIP, γ-LPH, α-MSH and β-endorphin in the intermediate lobe
• γ-MSH
• β-MSH

Although the N-terminal 5 amino acids of beta-endorphin are identical to the sequence of Met-enkephalin, it is not generally thought that beta-endorphin is converted into Met-enkephalin. Instead, Met-enkephalin is produced from its own precursor, proenkephalin.

The production of beta-MSH occurs in humans but not in mice or rats due to the absence of the enzymatic processing site in the rodent POMC.

Functions

• α-MSH produced by neurons in the arcuate nucleus has important roles in the regulation of appetite and sexual behavior, while α-MSH secreted from the intermediate lobe of the pituitary regulates the production of melanin.
• ACTH is a peptide hormone that regulates the secretion of glucocorticoids from the adrenal cortex.
• β-endorphin and met-enkephalin are endogenous opioid peptides with widespread actions in the brain.

See also

• melanocortin
• melanotan

External links

References

Further reading