Pancreatic Hormones Flashcards
Describe regulatory relationship between Insulin, Glucagon, and Somatostatin in pancreas
- A cell (glucagon) promotes both B and D
2. B and D both inhibit other two cell types
Describe mechanism of insulin/glucagon secretion
Key = closure of ATP-K pump
Insulin: high glucose -> high ATP -> closes ATP-K channel -> Ca channel opens
Glucagon: low glucose -> low ATP -> closes ATP-K channel -> Ca channel opens
Effect of ANS on insulin/glucagon
SNS decreases insulin
PNS increases insulin
Both increase glucagon
Aside from low glucose, what else decreases insulin?
Somatostatin
Leptin
a-Adrenergic activity
The B subunits of the insulin receptor have which activity?
Tyrosine kinase
Actions of insulin
Increase TG, protein, and glycogen synthesis (therefore decreases levels in blood)
Decrease blood KBs and K+
Which tissues have GLUT4 (insulin dependent) transporters?
Fat, skeletal muscle, heart
Where does insulin promote lipolysis?
OUTSIDE of adipocytes (Lipoprotein Lipase)
Inhibits hormone-sensitive lipase
Insulin degradation
5-10 min half-life
- Insulinases on cell membranes (liver and kidney)
- Receptor-mediated endocytosis (kidney)
Glucagon is inhibited by
Somatostatin
Insulin (not reciprocal)
Diabetogenic hormones
Cortisol
Growth Hormone
Glucagon
Epinephrine
Effect of diet on Insulin/Glucagon balance
Insulin really only goes down when fasting
Glucagon goes up if pure-protein diet
Type __ diabetes is common in dogs, while type __ diabetes is common in cats.
Dogs: Type 1
Cats: Type 2
How to treat type 1 diabetes
Administer insulin
How to treat type 2 diabetes
- Administer insulin
- Stimulate insulin release w/ sulfonylurea (closes the ATP-K channel in B cells)
- Increase receptor sensitivity w/ metformin
- Inhibit glucagon w/ GLP-1 agonists
- Diet/exercise
