Pramlintide (trade name Symlin) is an injectable
amylin
Amylin, or islet amyloid polypeptide (IAPP), is a 37-residue peptide hormone
Peptide hormones or protein hormones are hormones whose molecules are peptide, or proteins, respectively. The latter have longer amino acid chain lengths than the forme ...
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 ap ...
(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 othe ...
(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 includin ...
).
Pramlintide is sold as an acetate salt.
Pharmacology
Pramlintide is an analogue of
amylin
Amylin, or islet amyloid polypeptide (IAPP), is a 37-residue peptide hormone
Peptide hormones or protein hormones are hormones whose molecules are peptide, or proteins, respectively. The latter have longer amino acid chain lengths than the forme ...
, 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 the c ...
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 dimini ...
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 end ...
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 metabolism o ...
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, using ...
by slowing
gastric emptying Gastrointestinal physiology is the branch of Human body, human physiology that addresses the physical function of the Human gastrointestinal tract, gastrointestinal (GI) tract. The function of the GI tract is to process ingested food by mechanical a ...
, 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 Glucagon (medicati ...
, 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-enzymatic ...
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 is ...
plaques in
Alzheimer's disease
Alzheimer's disease (AD) is a neurodegeneration, neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in short-term me ...
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 Fibril, fibrillar morphology of 7–13 Nanometer, nm in diameter, a beta sheet (β-sheet) Secondary structure of proteins, secondary structure (known as cross-β) and ability to be Staining, ...
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