12: Endocrine Pancreas

Question 1

Three types of innervation to the endocrine pancreas

Answer 1

Adrengergic, cholinergic, peptidergic

Question 2

Three ways cells in the islets communicate

Answer 2

1. Ion concentrations
2. Gap junctions between a’s and B’s
3. Blood supply

Question 3

How does blood flow through the islets

Answer 3

Center receives blood first -> insulin released into blood flows by a and D cells so they can sense how much insulin is in blood

Question 4

C peptide secretion and function

Answer 4

Secreted equally with insulin - used as an endogenous insulin secretion marker

Question 5

Biphasic release of insulin

Answer 5

initial spike within minutes + further increase half hour to an hour later

Question 6

Exercise on blood sugar

Answer 6

Muscle contraction activates AMPK -> causes GLUT4 translocation so more glucose can enter cells

Question 7

Insulin actions on skeletal muscle

Answer 7

Increases: glucose uptake, glycogen synthesis, glycolysis, protein synthesis
Decreases: protein breakdown

Question 8

Insulin actions on liver cells

Answer 8

Increases: glycogen synthesis, glycolysis, hexose monophosphate shunt, pyruvate oxidation, lipid storage, protein synthesis
Decreases: gluconeogenesis, lipid oxidation, protein breakdown

Question 9

Insulin actions on adipose cells

Answer 9

Increases: glucose uptake, glycolysis, uptake of FAs
Decreases: lipolysis

Question 10

Insulin major effect on cells in general

Answer 10

Increase K uptake -> decreases K in ECM

Question 11

What three metabolic processes does glucagon increase

Answer 11

Gluconeogenesis, lipolysis, glycogenolysis

Question 12

Glucagon and insulin actions on one another

Answer 12

Glucagon inhibted by insulin, but glucagon stimulates insulin release

Question 13

How many cases of DM2 have insulin resistance?

Answer 13

95%

Question 14

Incretin effect

Answer 14

normal spike of insulin in healthy patients due to GI hormone release - over time, pts with insulin resistance lose normal incretin effect

Question 15

Environmental risks for DM 2

Answer 15

caloric excess, sedentary, maternal disease and nutrition, rapid post-natal growth, sleep debt, endocrine disrupters, chronic inflammation

Question 16

What happens when adipose tissue is inflamed in terms of insulin resistance?

Answer 16

Recruits M1 macrophages -> release of inflammatory markers (IL-6, TNFa, IFN-y) -> disruption of adipokines + release of FA’s

Question 17

Three types of medications for DM2 treatment

Answer 17

1. Insulin sensitizers
2. Sulfonylurea receptors
3. Insulin secretagogues

Question 18

Two types of insulin sensitizers

Answer 18

Biguanide drugs (metformin), TZDs

Question 19

What are sulfonylurea receptors associated with?

Answer 19

ATP-dependent K channels

Question 20

What causes DM 1?

Answer 20

T cell mediated destruction of B cells of pancreas -> inadequate insulin secretion

Question 21

When do sx start to appear with DM 1?

Answer 21

When about 80% of B cells are destroyed

Question 22

What causes DKA?

Answer 22

Decreased utilization of ketoacids

Question 23

Three major symptoms that occ with DM 1

Answer 23

Hyperkalemia, osmotic diuresis, glucosuria

Question 24

What causes hyperkalemia in DM 1?

Answer 24

Lack of insulin effect on Na/K ATPase

Question 25

What causes osmotic diuresis and glucosuria in DM 1?

Answer 25

Increased blood glucose increases filtered load of glucose, exceed reabsorption capacity of proximal tubule + water and electrolyte reabsorption is blunted

Question 26

What does polyuria cause in DM 1?

Answer 26

Increased excretion of Na and K even though urine concentration of electrolytes is relatively low

Question 27

Two major alleles associated with DM 1

Answer 27

HLA DQ2 and DQ8

Question 28

Environmental factors with DM 1

Answer 28

early exposure to cows milk, vitamin D deficiency, gluten intolerance, childhood infections, obesity

Question 29

Treatment for DM 1

Answer 29

Timing insulin doses to meal consumption to mimic physiological response