Hormones of the Pancreas Flashcards
What are 2 major hormones produced in the pancreas and what is their effect on glucose?
insulin - decrease Glc
glucagon - increase Glc
what is a normal glucose range?
5-6mM
what other 3 hormones affect Glc and how do they affect it?
cortisol - increases Glc
epinephrine - increases Glc
Growth hormone - increases Glc
what are the endocrine cells of the pancreas? exocrine cells?
endo - islets of langerhans
exo - acini
what are the 4 major cell types of the islet of Langerhans and what hormones do they produce?
A(alpha) - glucagon
B(beta) - insulin
D(delta) - somatostatin
F - pancreatic peptide
What is proinsulin?
Uncut insulin, consisting of A + B + C chains with little biologic activity
What is mature insulin? What is the piece cut off and what is its function?
mature insulin = A + B chain
C peptide cut off - no known function
what is the cleaving enzyme of proinsulin?
proprotein convertase
What occurs after cleavage of proinsulin?
post translational processing occurs in Golgi and secretory granules
Mature insulin complexed with zinc and C peptide released from G granules by exocytosis is regulated
What do stimulants of insulin release? (4pts)
sugars (Glc, mannose)
AAs (leucine)
Vagus nerve stimulation
sulfonylureas
What are molecules that amplify glucose?
enteric hormones (gastrin, secretin, cholecystokinin) Neural amplifiers (beta adrenergic effect of catecholamines) AAs (arginine)
what are two inhibitors of insulin release?
neural: alpha-adrenergic effect of catecholamines
humoral: somatostatin
How does food influence Glc, glucagn, and insulin levels?
Glc goes up first, then insulin
~1hr after meal is peak
Glucagon opposite of Glc (lowest ~1hr after meal)
Where are the 4 areas of the body that Glc can be utilized?
Brain
Muscle
Adipose tissue
liver
what is Glc converted to in the muscle?
glycogen and protein (also AA)
what is Glc converted to in adipose tissue?
triglycerides and FAs
what is Glc converted to in the liver?
glycogen and then stored
What effect does insulin have on the body?
Glc uptake into cells
glycogen synthesis
lipid synthesis
protein synthesis by increased AA uptake
is insulin anabolic or catabolic?
anabolic
How is Glc taken up into cells?
by facilitated diffusion using glucotransporters GLUT1-5