Pancreatic hormones

Amylin

• slows gastric emptying

• increase satiety

• co-secreted with insulin and reduces glucagon

• maybe a bone impact/calcitonin?

  • it is similar to calcitonin

Somatostatin

• Inhibits both glucagon and insulin

• Inhibits GH

• “Brake” for secretion of other hormones

• Exogenous treatment with SS for tumors, excess GH diorders, etc.

Pancreatic Polypeptide

• Stimulated by CCK

• Reduced by ghrelin

• slows pancreatic secretions

• Reduces appetite

• Slows movement of food stomach to SI

Glucagon

• When blood glucose is too low

• Proglucagon cleaved into either

  • Glucagon+ (pancreas)

  • GLP-1+ (gut, brain, etc.)

• Binds glucagon receptor an triggers glucose formation, glycogen breakdown

• Mostly in liver

Insulin

• When blood glucose is too high

• Proinsulin is cleaved into insulin and C-peptide

• Insulin secreted into blood to stimulate glucose uptake in target cells

• C-peptide has no biological function, but is used to measure insulin

role of insulin in target tissue (not necessarily necessary to know i think)

• Liver

  • Dec glucogeogenesis

  • Dec glycogenolysis

• Muscle

  • Inc glucose uptake

• Adipose

  • Dec lipolysis

• Brain

  • Dec appetite

• Mitochondria

  • Dec oxidative stress

• Endothelium

  • Inc vasodilation

• Lipids

  • Inc HDL

  • dec triglyceride

  • Large buoyant LDL

• Kidney

  • dec gluconeogenesis

  • dec albuminuria

  • dec glomerulosclerosis

Coordination of blood glucose

• Glucagon and insulin coordinate to maintain

  blood glucose at appropriate range (72-100

  mg/dL)

• When blood glucose levels are high

  (>100 mg/dL, hyperglycemia), insulin triggers

  cells to take up glucose

  • When blood glucose is low (<72 mg/dL,

    hypoglycemia), glucagon triggers release of

    glucose (and glycogen)

A1C

• Test to detect avg blood suagr level over 3 months

• Tests glucose coating hemoglobin

• High A1C = inc (sustained) blood glucose = inc risk of diabetes

• prediabetes: 5.7-6.4%

• Diabetes: 6.5%+

GLUT4

• Insulin binding

• P13K signaling triggers exocytosis of GLUT4 to cells membrane

• High GLUT4 at membrane takes up glucose from blood along concentration gradient

What are the pancreatic islets called

Pancreatic islets