Pancreas Flashcards
pancreas secretions
insulin
glucagon
somatostatin
pancreatic polypeptide
beta cells
insulin
alpha cells
glucagon
delta cells
somatostatin
remaining cells
pancreatic polypeptide
insulin structure
peptide hormone
A and B chains linked two disulfide bonds
C peptide
secreted with insulin
-good marker of insulin secretion from beta cells
insulin action
up-regulates GLUT-4 transporters
-muscle and adipose tissue
promotes formation of glycogen in liver and muscle
inhibits glycogenolysis and gluconeogenesis
decreased FA and ketoacid concentration in blood
stimulates fat deposition and inhibits lipolysis
promotes K uptake into cells
GLUT 2
low affinity
- pancreatic beta cells
- ilver
- intestine
- kidney
GLUT 1 and 3
allow glucose to go to brain
GLUT 4
skeletal muscle and adipose
insulin-responsive
insulin and potasslum
promotes movement of potassium into cells
high insulin:glucagon
anabolic state
low insulin:glucagon
catabolic state
insulin deficiency
leads to ketosis
oral vs. IV glucose
oral more powerful
-bc GIP release increases effect of insulin
DM I
insulin-dependent - destruction of beta cells
increased blood glucose, FA, ketoacids, AA
increased ketoacids
metabolic acidosis (diabetic ketoacidosis)
polyuria
hyperkalemia
DM I and polyuria
glucose is an osmotic diuretic
DM II
insulin-independent - associated with obesity
insulin resistance
normal insulin levels, no response
blood glucose elevated fed and fasting states
Tx: caloric restriction, weight reduction, sulfonylurea drugs and biguanide drugs
biguanide drugs
upregulate receptors for insulin
Tx for type II DM
glucagon secretion
stimulated by low blood glucose
inhibited by insulin
stimulated by protein ingestion (Arg, Ala)
stimulated by fasting and exercise
stimulated by alpha-adrenergic stimulation
action of somatostatin
from delta cells
inhibit secretion of insulin and glucagon
modulate response of insulin and glucagon
type I DM
immune mediated
beta cell destruction
insulin dependent
ketoacidosis**
type II DM
insulin resistance
overweight, usually no ketoacidosis
gestational DM
during pregnancy
diabeticogenetic effect
acromegaly and hypercortisolism
family Hx
more with type II DM
obesity
BMI > 30
kg / m~2
pre-diabetic
fasting 100-126
2 hour oral glucose tolerance 140-200
criteria for diabetes Dx
fasting
oral glucose tolerance
random glucose
hemoglobin A1c
incretin effect
oral glucose - stimulates GLP-1
-potentiates insulin release from beta cells
no GLP-1 with IV
glucagon and incretins
glucagon, GLP-1, GLP-2 from same gene
amylin
also from beta cells
suppress appetite
inhibit gastric emptying
type 2 diabetics
reduced incretin effect
can use GLP-1 agonists
fruity odor on breath
indicative of ketones
type 1 DM
cell mediated autoimmune
T cell mediated**
predictable with islet autoantibodies
pre-diabetes
beta cell mass decreases
after autoantibodies present
genes associated with type I DM
HLA
also INS, PTPN22
insulin in thymus - protective - recognize as self
MHC
class II - DP DQ DR class I - B C A
major islet autoantigens
ZnT8
IA-2
GAA
mIAA
diabetic ketoacidosis
C peptide of zero
common to DM I and DM II
nonenzymatic glycosylation of proteins
