[Amylin--its physiological role in humans].
Amylin is a polypeptide hormone composed of 37 aminoacids, that is produced in pancreatic beta-cells, and that was discovered in 1987. Releasing amylin into the circulation is increased postprandially, proportionally to the amount of digested food. Daily profile of amylin plasma levels corresponds to the profile of insulin. Normal plasma levels of amylin vary from 4 pmol/L (fasting) to 25 pmol/L (postprandially). Receptors for amylin are highly concentrated especially in the central nervous system--area postrema and nucleus accumbens. There is a 20% sequence homology between amylin, calcitonin and adrenomedullin and 44% homology with calcitonin gene--related peptide. Amylin contributes to the regulation of postprandial glycaemia by suppression of glucagon release and by regulation of gastric emptying. Deficit os amylin is typical for diabetes mellitus type 1 or for the late stage of diabetes type 2. Insulin resistance in obese patients is characterized by increased levels of both insulin and amylin. Amylin decreases food intake and participates in the regulation of body weight. Some biochemical forms of amylin cause proliferation of osteoblasts and inhibit bone resorption. Amylin modulates insulin sensitivity of skeletal muscle, contributes to the regulation of blood pressure and causes vasodilatation.
Bronský
J
J
Ustav klinické biochemie a patobiochemie 2. LF UK a FN Motol, Praha. bronsky@email.cz
Chada
M
M
Kotaska
K
K
Průsa
R
R
D000682:Amyloid / Q000502:physiology*; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001842:Bone and Bones / Q000378:metabolism; D003920:Diabetes Mellitus / Q000097:blood; D004435:Eating / Q000502:physiology; D005934:Glucagon / Q000378:metabolism; D006801:Humans; D058228:Islet Amyloid Polypeptide
D000682:Amyloid; D001786:Blood Glucose; D058228:Islet Amyloid Polypeptide; D005934:Glucagon