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Flashcards in Diabetes Deck (27):
1

What are the 4 ways that insulin decreases blood glucose?

- incr. glucose uptake into muscle and fat cells
- incr. glycogen synthesis
- dec. gluconeogenesis
- dec. glycogen breakdown

2

Glucagon stimulates what 3 mechanisms?

- gluconeogenesis
- glycogenolysis
- lipolysis

3

Beta cells respond to which two stimuli?

absolute glucose concentration
rate of change of blood glucose

4

Responding to a change in blood glucose has 2 phases which are?

1. Initial rapid phase (release of stored hormone)
2. Slower delayed phase (continued release of stored hormone and NEW synthesis).

5

How is insulin secreted?

ATP-sensitive K+ channels determine the resting membrane potential in B-cells.

Glucose enters B-cells via GLUT-2

Glucose metabolised by glucokinase and glycolysis increases intracellular ATP.

Incr. ATP blocks K(ATP) channels causing depolarisation, CA2+ channels open.

Ca2+ signal induces insulin secretion.

6

Insulin receptor is what kind of receptor?

Tyrosine kinase receptor. When insulin binds, it leads to phosphorlylation.

7

Diabetes effects what % of the population?

3-5%

8

The degeneration of B-cells is what type of diabetes?

Type 1

9

What % of diabetes is Type 1?

15-20%

10

What main 2 conditions can result from low insulin?

Hyperglycaemia
- liver/skeletal muscle can't store glycogen
- Tissues unable to take up and use glucose

Ketosis
- inhibition of FA synthesis
- ketones form (metabolic acidosis)
- aceto-acetate forms
- B-hydroxybutyrate
- acetone

11

What was wrong using pork or beef insulin to treat IDDM?

Poorly tolerated by many patients and different aa in peptide chains

12

What is Humulin?

Human insulin. This is genetically engineered and better tolerated.

13

3 ways insulin can be injected?

Sub-cutaneously
Jet-injection
Pump

14

What is the most fast acting type of injectable insulin?

Humalog (acts in 45-90min, stops after 3-4 hrs)

15

What is the fast acting/regular type of injectable insulin?

Humulin (acts in 2-5 hrs, stops after 5-8 hrs)

16

What is the intermediate acting injectable type of insulin?

NPH/Lente (acts in 6-12 hrs, stops 20-24 hrs)

17

What is a long acting insulin type?

Ultralente (prolongs entry of insulin into blood stream for 4-6 hrs, stops after 28 hrs)

18

What is an ultra-long acting insulin type?

Glargine (constant rate for 24 hrs)

19

Which type of Diabetes is autoimmune?

Type 1

20

When does NIDDM develop?

After 35 years of age

21

What does NOT form in type 2 diabetes?

Ketosis

22

What is type 2 diabetes due to?

Insensitivity of target cells to insulin.

23

What 2 factors causes insulin resistance?

Reduced number of insulin receptors
Problem in pathway of insulin action.

24

What is used to treat type 2 diabetes?

Oral hypoglycaemic agents
- sulfonylureas
- meglinitides
- Biguanides

25

How do sulfonylureas increase the release of insulin in type 2 diabetes?

high affinity for sulfonylureas on K(ATP) channels

Block K(ATP) channels

Depolarisation in the cells

Incr. insulin release

26

How do meglinitides increase the release of insulin in type 2 diabetes?

Work on the pancreas to promote insulin secretion

Same as sulfonylureas, except different binding site.

27

How do biguanides increase the release of insulin in type 2 diabetes?

Reduces liver gluconeogenesis

Activates AMP-activated protein kinase

Incr. glucose uptake and utilisation