Regulation of insulin secretion (Chemical,Hormonal and Neural factors)

Insulin was discovered in 1921 by BANTING and BEST.  

It is a peptide hormone composed of 51 amino acid residues.

Insulin has a molecular weight of 5808.

Insulin is synthesized in the beta cells of the pancreas.

The name insulin comes from the Latin word insula for "island" 

Insulin is initially produced as a single polypeptide chain, preproinsulin which contain 110 amino acid residue.

1unit of insulin is secreted per hour under basal conditions.

Regulation of insulin secretion is by Chemical, hormonal and neural factors

Chemical factors

1. Glucose, amino acids (arginine, etc.), fatty acids, and ketone bodies stimulate  the secretion of insulin. 

Hormonal factors

1. Glucagon increase insulin release
2. Somatostatin inhibits the insulin release
3. Growth hormone,Thyroid hormone,cortisol produce  hyperglycemia.

Neural factors

1. Alpha2 stimulation decreases insulin secretion.
2. B2 stimulation increases the insulin level.
3. Cholinergic stimulation increases insulin.