is a 14 amino acid peptide
originally isolated from the skin
of a frog
. It has two known homologs
called neuromedin B
and gastrin releasing peptide
. It stimulates gastrin
release from G cells
. It activates three different G-protein
known as BBR1 2 & 3. It also activates these receptors in the brain
. Together with cholecystokinin
it is the second major source of negative feedback
signals that stop eating behaviour.
Bombesin is also a tumor marker for lung cancer, gastric cancer and neuroblastoma.