Mammalian bombesin-like peptides

Mammalian bombesin-like peptides share structural homology with the large family of amphibian bombesin-like peptides. At present there is evidence for two classes of mammalian bombesin-like peptides, the gastrin-releasing peptides (GRP) and the ranatensin-like peptides. GRPs are distributed throughout the mammalian central nervous system, peripheral nervous system, gastrointestinal (GI) tract and the lung where they act as neurotransmitters, autocrine hormones and growth factors. Less is known about the ranatensin-like peptides which to date have been detected only in the brain and spinal cord. The large number of amphibian bombesin-like peptides suggests that still more mammalian bombesin-like peptides remain to be characterized. The challenge will be to determine the key physiological roles of the entire family of these peptides.