Pancreatic Hormones

Question 1

what do alpha cells secrete

Answer 1

glucagon, proglucacon

Question 2

what do beta cells secrete

Answer 2

insulin
C peptide
proinsulin
islet amyloid polypeptide
GABA

Question 3

what do delta cells secrete

Answer 3

somatostatin

Question 4

what do episolin cells secrete

Answer 4

ghrelin

Question 5

what do PP or F cells secrete

Answer 5

pancreatic polypeptide

Question 6

steps on insulin secretion

Answer 6

Insulin gene translated to preproinsulin in ER, preproinsulin cleaved immediately. Proinsulin packaged into granules in Golgi. Proinsulin converted to insulin and C-peptide in secretory vesicles.

Question 7

half life of insuline

Answer 7

3-5 minutes

Question 8

how does glucose affect insulin

Answer 8

most potent stimulator of release

increass intracellular ATP, inhibits K channel, results in Ca++ inflex

Question 9

how does vagal stimulation affect insulin

Answer 9

acetylcholine activate M3 receptos and increass intracellular Ca

Question 10

how do hormones affect insulin

Answer 10

GLP1 amplifies insulin release

somatostatin inhibits insulin releasess

Question 11

how do catecholamines affect insulin

Answer 11

beta adrenergic stim (epinephrine) can amplify secretion

Question 12

how does alpha adrennergic stimulation affect insuline

Answer 12

inhibit insulin release

Question 13

Describe the cellular events that take place during glucose and acetylcholine stimulated insulin secretion.

Answer 13

Glucose moves down conc. gradient into cell (likely thru glucose transporter 2), leads to increased ATP in cell. This inhibits K channel, memb depolarizes, and Ca flows in and is involved in insulin release.

Question 14

cellular consequences that occur following activation of the insulin receptor.

Answer 14

activates intracellular signaling pathways. Outcomes are mitogenic (cellular growth), and metabolic.

Question 15

can glucose move across the cell membrane

Answer 15

no

Question 16

GLUT 4

Answer 16

on skeletal muscle and adipose tissue

insulin mediated uptake of glucose

Question 17

GLUT 2

Answer 17

pancreatic B cells, liver/kidney.gut, leads to insulin release

Question 18

metabolic consequences of insulin on liver

Answer 18

stimulate glycogen syn/storage. inhibit glycogen breakdown, increase protein syntehsis
inhibit glycogenolysis, inhibit ketogenesis, and inhibit gluconeogenesis.

Question 19

affect of insulin on adipose

Answer 19

Increase triglyceride storage by promoting free FA uptake, promote esterification of free Fas, and inhibit lipolysis.

Question 20

affect of insulin on skeletal muscle

Answer 20

Increase protein synth by increasing AA uptake. Increases glycogen synth by increasing glucose uptake, increasing glycogen synthase activity, and inhibiting glycogen phosphorylase.

Question 21

main difference between glucagon and insulin

Answer 21

insuline promotes energy storage, glucagon promotes energy mobilization

Question 22

affect of insulin on glucose in the blood

Answer 22

decreases

Question 23

IAPP

Answer 23

produced by B cells. Packaged in same vesicles as insulin. Decreases glucagon secretion, inhibits GI motility, regulates appetite. Analogue can be used for type I and II diabetes.

Question 24

pancreatic polypeptides

Answer 24

secreted by F or PP cells in pancreas. Regulated by vagus nerve and neuronal control. Regs exocrine function of pancreas, gallbladder contraction, gastric acid secretion, and GI motility.

Question 25

somatostatin

Answer 25

secreted by delta cells, secreted in response to same stimuli as insulin. Produced also in brain, periph neurons, endocrine cells of stomach/pancreas. Inhibits insulin secretion thru activation of SSTR-5

Question 26

ghrelin

Answer 26

Secreted by epsilon cells

Question 27

GLP1

Answer 27

GLP1 secreted in response to meal, is insulin secretion amplifier. GLP1 promotes production and secretion of insulin and somatostatin (is neg reg of insulin). GLP1 protects and promotes growth of B cells.

Question 28

what can break down GLP1

Answer 28

DPP-4