Type 1 Diabetes Flashcards
Where does insulin secreted by the pancreas mostly go?
To the liver via the portal vein.
4 important cell types in the islets of Langerhans?
beta cells - insulin
alpha cells - glucagon
delta cells - somatastatin (supresses both insulin and glucagon)
pancreatic polypeptide cells - unknown function
In what form is insulin synthesize in beta cells? How is it released?
Starts as pre-proinsulin.
Cleaved in ER to proinsulin.
Proinsulin cleaved to insulin + C peptide.
Insulin + C peptide are released from secretory vesicles.
4 necessary conditions for proper insulin function?
Beta cells must be there. <- problem in T1D
Beta cells must make insulin.
Beta cells must secrete insulin in response to glucose.
Insulin signaling in target cell must function.
Other molecule missing in T1D that may be useful to administer?
IAPP aka amylin.
How is endogenous insulin measured?
By measuring levels of C-peptide, not insulin itself.
allows you to monitor while giving exogenous insulin
3 different ways to stimulate insulin secretion?
Nutrient load - mainly glucose.
Autonomic - seeing/smelling food -> vagal stimulation. (also fight-or-flight turns it off).
Hormonal - incretins (GLP-1 and GIP)
2 ways to inhibit insulin secretion?
Starvation/hypoglycemia.
Hormonal - glucagon, epinephrine, growth hormone, cortisol.
2 types of T1D?
Autoimmune (most common)
Non-autoimmune
Other, less common forms of diabetes mellitus? (aside from T1D, T2D, and gestationaL)
LADA - latent autoimmune diabetes of adulthood. Monogenic diabetes (beta cells don't work properly) Secondary to other conditions (drugs, endocrinopathies, infections, etc.) Pancreatic disease.
3 major things that distinguish T1D from T2D?
There’s no insulin at all.
Way easier to get diabetic ketoacidosis (DKA).
Auto-antibodies.
Do beta cells die in T2D?
Yes, but only late in the disease process.
Boards question: You see a women with recurrent yeast infections…
Rule out diabetes.
Why does glucose get into the urine?
Transporters for reabsorption are overwhelmed.
Prevalence of T1D in US people under 20?
Geographic bias?
0.25%
More common in North American and northern European areas.