Pramlintide (trade name Symlin) is an injectable

amylin Amylin, or islet amyloid polypeptide (IAPP), is a 37-residue peptide hormone. It is co-secreted with insulin from the pancreatic β-cells in the ratio of approximately 100:1 (insulin:amylin). Amylin plays a role in glycemic regulation by slo ...

analogue drug for

diabetes Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level (hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ...

(both type 1 and 2), developed by

Amylin Pharmaceuticals Amylin Pharmaceuticals is a biopharmaceutical company based in San Diego, CA, that was founded in 1987. The company was engaged in the discovery, development and commercialization of drug candidates for the treatment of diabetes, obesity and o ...

(now a wholly owned subsidiary of

AstraZeneca AstraZeneca plc () is a British-Swedish multinational pharmaceutical and biotechnology company with its headquarters at the Cambridge Biomedical Campus in Cambridge, England. It has a portfolio of products for major diseases in areas includ ...

). Pramlintide is sold as an acetate salt.

Pharmacology

Pramlintide is an analogue of

, a small peptide

hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...

that is released into the

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in th ...

stream by the

β cells Beta cells (β-cells) are a type of cell found in pancreatic islets that synthesize and secrete insulin and amylin. Beta cells make up 50–70% of the cells in human islets. In patients with Type 1 diabetes, beta-cell mass and function are dimi ...

of the

pancreas The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an en ...

along with

insulin Insulin (, from Latin ''insula'', 'island') is a peptide hormone produced by beta cells of the pancreatic islets encoded in humans by the ''INS'' gene. It is considered to be the main anabolic hormone of the body. It regulates the metabol ...

after a meal. Like insulin, amylin is completely absent in individuals with Type I diabetes. In synergy with endogenous amylin, pramlintide aids in the regulation of blood

glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, usi ...

by slowing

gastric emptying Gastrointestinal physiology is the branch of human physiology that addresses the physical function of the gastrointestinal (GI) tract. The function of the GI tract is to process ingested food by mechanical and chemical means, extract nutrients and ...

, promoting

satiety Satiety ( ) is a state or condition of fullness gratified beyond the point of satisfaction, the opposite of hunger. It is a state which induces meal termination.Hetherington, M.Sensory-specific satiety and its importance in meal termination ''Neuro ...

via

hypothalamic The hypothalamus () is a part of the brain that contains a number of small nuclei with a variety of functions. One of the most important functions is to link the nervous system to the endocrine system via the pituitary gland. The hypothalamus i ...

receptors (different receptors than for

GLP-1 Glucagon-like peptide-1 (GLP-1) is a 30- or 31-amino-acid-long peptide hormone deriving from the tissue-specific posttranslational processing of the proglucagon peptide. It is produced and secreted by intestinal enteroendocrine L-cells and certa ...

), and inhibiting inappropriate secretion of

glucagon Glucagon is a peptide hormone, produced by alpha cells of the pancreas. It raises concentration of glucose and fatty acids in the bloodstream, and is considered to be the main catabolic hormone of the body. It is also used as a medication to trea ...

, a catabolic hormone that opposes the effects of insulin and amylin. Pramlintide also has effects in raising the acute first-phase insulin response threshold following a meal. Both a reduction in

glycated hemoglobin Glycated hemoglobin, also known as HbA1c, glycohemoglobin, hemoglobin A1c, A1C, is a form of hemoglobin (Hb) that is chemically linked to a sugar. Most monosaccharides, including glucose, galactose and fructose, spontaneously (i.e. non-enzymati ...

and weight loss have been shown in insulin-treated patients with type 2 diabetes taking pramlintide as an adjunctive therapy.

Research Applications

In the research field, pramlintide has been experimented with and used as a potential treatment drug. Pramlintide has demonstrated its ability to decrease

amyloid beta Amyloid beta (Aβ or Abeta) denotes peptides of 36–43 amino acids that are the main component of the amyloid plaques found in the brains of people with Alzheimer's disease. The peptides derive from the amyloid precursor protein (APP), which i ...

plaques in Alzheimer's disease mouse models.

Approval

Pramlintide has been approved by the FDA, for use by type 1 and type 2 diabetic patients who use insulin. Pramlintide allows patients to use less insulin, lowers average blood sugar levels, and substantially reduces what otherwise would be a large unhealthy rise in blood sugar that occurs in diabetics right after eating. Apart from insulin analogs, pramlintide is the only drug approved by the FDA to lower blood sugar in type 1 diabetics since insulin in the early 1920s.

Design and structure

Since native human amylin is highly

amyloid Amyloids are aggregates of proteins characterised by a fibrillar morphology of 7–13 nm in diameter, a beta sheet (β-sheet) secondary structure (known as cross-β) and ability to be stained by particular dyes, such as Congo red. In the hu ...

ogenic and potentially toxic, the strategy for designing pramlintide was to substitute residues from rat amylin, which is less amyloidogenic although not completely (but would presumably retain clinical activity). Proline residues are known to be structure-breaking residues, so these were directly grafted into the human sequence. Despite its enhanced stability compared to human amylin, pramlintide is still able to organize into amyloid material. Amino acid sequences: Pramlintide as protein is (positively charged).

References

External links

www.symlin.com
- product website
www.amylin.com
- Symlin page on the Amylin Pharmaceuticals website {{Oral hypoglycemics and insulin analogs Anti-diabetic drugs Diabetes Human proteins AstraZeneca brands Recombinant proteins Peptide hormones