Bombesin is a 14-

amino acid Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although over 500 amino acids exist in nature, by far the most important are the 22 α-amino acids incorporated into proteins. Only these 22 a ...

peptide Peptides are short chains of amino acids linked by peptide bonds. A polypeptide is a longer, continuous, unbranched peptide chain. Polypeptides that have a molecular mass of 10,000 Da or more are called proteins. Chains of fewer than twenty am ...

originally isolated from the

skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other animal coverings, such as the arthropod exoskeleton, have different ...

of the

European fire-bellied toad The European fire-bellied toad (''Bombina bombina'') is a species of fire-bellied toad native to eastern parts of mainland Europe, where it can be found near waterbodies such as ponds and marshes. It is known for its red colored belly used to wa ...

(''Bombina bombina'') by

Vittorio Erspamer Vittorio Erspamer (30 July 1909 – 25 October 1999) was an Italian pharmacologist and chemist, known for the identification, synthesis and pharmacological studies of more than sixty new chemical compounds, most notably serotonin and octopamine. ...

''et al.'' and named after its source. NIHMSID 45053. It has two known

homologs Homologous chromosomes or homologs are a set of one maternal and one paternal chromosome that pair up with each other inside a cell during meiosis. Homologs have the same genes in the same loci, where they provide points along each chromosome th ...

mammals A mammal () is a vertebrate animal of the class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three middle e ...

called

neuromedin B Neuromedin B (NMB) is a bombesin-related peptide in mammals. It was originally purified from pig spinal cord, and later shown to be present in human central nervous system and gastrointestinal tract. Sequence The sequence of the C-terminal decap ...

and

gastrin-releasing peptide Gastrin-releasing peptide GRP, is a neuropeptide, a regulatory molecule encoded in the human by the ''GRP'' gene. GRP has been implicated in a number of physiological and pathophysiological processes. Most notably, GRP stimulates the release of g ...

. It stimulates

gastrin Gastrin is a peptide hormone that stimulates secretion of gastric acid (HCl) by the parietal cells of the stomach and aids in gastric motility. It is released by G cells in the pyloric antrum of the stomach, duodenum, and the pancreas. ...

release from

G cells A G cell or gastrin cell is a type of cell in the stomach and duodenum that secretes gastrin. It works in conjunction with gastric chief cells and parietal cells. G cells are found deep within the pyloric glands of the stomach antrum, and occasi ...

. It activates three different

G-protein G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. Their ...

-coupled

receptors Receptor may refer to: *Sensory receptor, in physiology, any neurite structure that, on receiving environmental stimuli, produces an informative nerve impulse *Receptor (biochemistry), in biochemistry, a protein molecule that receives and responds ...

known as BBR1, -2, and -3. It also activates these receptors in the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

. Together with

cholecystokinin Cholecystokinin (CCK or CCK-PZ; from Greek ''chole'', "bile"; ''cysto'', "sac"; ''kinin'', "move"; hence, ''move the bile-sac (gallbladder)'') is a peptide hormone of the gastrointestinal system responsible for stimulating the digestion of fat a ...

, it is the second major source of

negative feedback Negative feedback (or balancing feedback) occurs when some function (Mathematics), function of the output of a system, process, or mechanism is feedback, fed back in a manner that tends to reduce the fluctuations in the output, whether caused ...

signals that stop eating behaviour. Bombesin is also a

tumor A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

marker for small cell carcinoma of lung, gastric cancer, pancreatic cancer, and

neuroblastoma Neuroblastoma (NB) is a type of cancer that forms in certain types of nerve tissue. It most frequently starts from one of the adrenal glands but can also develop in the head, neck, chest, abdomen, or Vertebral column, spine. Symptoms may include ...

Receptors

The

anuran A frog is any member of a diverse and largely semiaquatic group of short-bodied, tailless amphibian vertebrates composing the order Anura (coming from the Ancient Greek , literally 'without tail'). Frog species with rough skin texture due to ...

receptor homologue is termed (). Iwabuchi ''et al.'' 2003 discovered a

chicken The chicken (''Gallus gallus domesticus'') is a domesticated subspecies of the red junglefowl (''Gallus gallus''), originally native to Southeast Asia. It was first domesticated around 8,000 years ago and is now one of the most common and w ...

(''Gallus domesticus'') receptor which is homologous to both the and fBB₄ and so they named it .

Effects

Erspamer 1988 finds bombesin has a similar effect on the chicken to ranatensin, unreliably increasing or decreasing blood pressure.

References

{{Neuropeptides N-Acyltryptamines Imidazoles Neuropeptides Pyrrolidones

Receptors

Effects

See also

References