Proopiomelanocortin

Pro-opiomelanocortin (POMC) is a precursor polipeptide that is built of 241 amino acid residues. It is synthetised in corticotroph cells of the anterior and intermedate lobes of the pituitary.

From the large molecule of POMC there are derived several important biologically active substances. Depending on the stimulus and site of production POMC can be cleavaged into any of the following:

• ACTH and β-LPH in the anterior lobe with CRH stimulation
• CLIP, γ-LPH, α-MSH and β-endorphin in the intermedate lobe with dopamine stimulation
• other products with unclear actions are :
  • γ-MSH
  • met-enkephalin