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Pathophysiology of diabetes mellitus

Insulin

composition

Insulin is a polypeptide consisting of 51 amino acids, has two peptide chains: the A chain, of 21 amino acids, and the B chain, of 30 amino acids

secretion

insulin secretion occurs in two periods, one of stimulation and another baseline; the first happens when food is ingested and a synchronization is performed perfect between glucose concentrations and those of plasma insulin. The second appears during fasting periods, carries an average secretion from 0.25 to 1.5 IU / h and constitutes about 50% of the secretion total insulin in 24 h

Influential factors in insulin secretion

glucose

incretins

amino acids

fat (triglyceride, free fatty acids and ketone bodies)

hormones

action

Insulin increases glucose transport in tissues adipose and muscle and inhibits its liver production.

Glucose

transport

There are several types of glucose transporters, however, only GLUT-4 is insulin dependent to exert its effect

Counter-regulating hormones

they have the function of raise blood glucose causing degradation hepatic glycogen by increasing glucose synthesis at the liver level and by decreasing its uptake in peripheral tissue

cortisol, growth hormone, catecholamines, glucagon

Insulin resistance

is a pathological state in which there is a lack of response of the target tissue

associated with several chronic diseases, such as obesity, hypertension and diabetes

Various studies suggest that the problem, especially in DM2, is in the post-receptor, since IR tyrosine kinase activity is decreased in patients with diabetes, which may be a consequence of an increase in the activity of the tyrosine phosphatase

Frida Olivia López Méndez