Diabetes-2 Flashcards
how can you describe insulin release
biphasic
what does it mean that insulin release is biphasic (what are the phases)
2 phases, first is a spike and it descends a bit then second is more rounded increase then down again
what happens in T2DM with biphasic release
the first phase is missing, the second phase is normal
what happens in T1DM with biphasic release
both phases absent, its just a straight line of insulin release (being none)
what happens to ions in insulin secreting cells with low plasma glucose
K+ exits the cells, making the inside more negative
what happens to ions in insulin secreting cells with high plasma glucose
block K+ leaving, Ca++ enters and insulin release
what does adding glucose do to membrane from beta cells
increases depolarization, so more insulin secretion
what is the mechanism of action of sulfonylureas
inhibit SUR1 , part of the K ATP channels (inhibiting the channel causes insulin release)
what is Kir6.2
pore forming subunit to allow K+ to pass through
what does ATP do to Kir6.2
inhibits it
what is the mechanism of diazoxide - what does this cause
binds to SUR1 to open channel (reduces insulin secretion)
what disease state do you use diazoxide for
hypoglycemia
what is a drug we use to inhibit insulin release
diazoxide
what do anabolic hormones do
uptake and store glucose (as polymer glycogen), amino acids and fats, inhibits catabolism
is insulin anabolic or catabolic
anabolic
what does insulin do to the liver
inhibits glycogenolysis and gluconeogenesis, stimulates glycogen synthesis, increases lipogenesis —> increases glycogen and triglyceride stores
what does insulin do to the muscle
increase glucose uptake by GLUT4 and stimulates glycogen synthesis —> increase glycogen stores
what does insulin do to the adipose tissue
increase glucose uptake by GLUT4, stimulates glycerol and fatty acid synthesis (end products of glucose metabolism) —> increase glycogen and triglyceride stores
which tissues get increase TG with insulin
liver and adipose
which tissues get increase glycogen with insulin
adipose, muscle and liver
which tissues get both increased glycogen and TG stores with insulin
adipose and liver
which tissues only get increased glycogen stores with insulin
muscle
what kind of receptors does insulin bind to (what mechanism)
tyrosine kinase linked receptors
what subunits are in the tyrosine kinase linked receptors that insulin bind to
2alpha and 2beta
what happens when insulin binds to its receptors
dimerization and auto phosphorylation on tyrosine residues
what happens when there is dimerization and auto phosphorylation on tyrosine residues
phosphorylation of insulin receptor substrate (IRS) proteins
what do IRS (insulin receptor substrate) proteins do
interact with -SH2 domain
what does insulin do to glycogen fat and protein formation
increase
what does insulin do to glucose uptake
increase
what does insulin do to glucose utilization
increase
what does insulin do to formation of glucose from glycogen fat and protein
decrease
what does insulin do to growth
increase
what does insulin do to gene expression
increase
what does insulin do to blood glucose
decrease