Endocrinology MPB 4153 : Hormone of Pancreas: Insulin
Tanjungpura University
Definition and Notes
INSULIN HORMONE
The role of metabolism is influenced by the endocrine function of
the pancreas located in the islets of Langerhans, in the form of epithelial
cells scattered throughout the organ. Two hormones that affect
carbohydrate metabolism are produced by the islets of Langerhans,
namely insulin by beta cells and glucagon by alpha cells. In addition,
delta cells have also been known to store and secrete the hormone
somatostatin (Harper at al., 1979: 544).
The mechanism of insulin formation is through the formation of a
small protein which is synthesized in the rough endoplasmic reticulum as
preproinsulin. Prepeproinsulin will break down into proinsulin. Proinsulin
will break down again in the Golgi apparatus to form insulin. Insulin will
be packaged with a number of proinsulin that has not broken down into
membrane-bound secretory granules. Membrane-bound secretory
granules will remain in the cytoplasm until insulin secretion is triggered.
Insulin is a protein hormone produced by the islets of Langerhans
which make up 1% of pancreatic tissue. In pancreatic beta cells, insulin is
synthesized like other proteins, via ribosomes and endoplasmic reticulum.
Approximately 50 units of insulin are required daily, and 1/5 of this
amount is stored in the human pancreas.
Insulin is produced initially as a preprohormone, then turns into a
prohormone and becomes active as the insulin hormone. Insulin synthesis
begins in the form of preproinsulin (insulin hormone precursor) in the
endoplasmic reticulum of the beta cells. Furthermore, the peptidase
Tanjungpura University
Definition and Notes
INSULIN HORMONE
The role of metabolism is influenced by the endocrine function of
the pancreas located in the islets of Langerhans, in the form of epithelial
cells scattered throughout the organ. Two hormones that affect
carbohydrate metabolism are produced by the islets of Langerhans,
namely insulin by beta cells and glucagon by alpha cells. In addition,
delta cells have also been known to store and secrete the hormone
somatostatin (Harper at al., 1979: 544).
The mechanism of insulin formation is through the formation of a
small protein which is synthesized in the rough endoplasmic reticulum as
preproinsulin. Prepeproinsulin will break down into proinsulin. Proinsulin
will break down again in the Golgi apparatus to form insulin. Insulin will
be packaged with a number of proinsulin that has not broken down into
membrane-bound secretory granules. Membrane-bound secretory
granules will remain in the cytoplasm until insulin secretion is triggered.
Insulin is a protein hormone produced by the islets of Langerhans
which make up 1% of pancreatic tissue. In pancreatic beta cells, insulin is
synthesized like other proteins, via ribosomes and endoplasmic reticulum.
Approximately 50 units of insulin are required daily, and 1/5 of this
amount is stored in the human pancreas.
Insulin is produced initially as a preprohormone, then turns into a
prohormone and becomes active as the insulin hormone. Insulin synthesis
begins in the form of preproinsulin (insulin hormone precursor) in the
endoplasmic reticulum of the beta cells. Furthermore, the peptidase
