Lecture 3&4

Question 1

Define hyperglycemia

Answer 1

Elevated blood glucose levels due to the inability to regulate blood glucose

Question 2

TRUE OR FALSE

Type 2 diabetes begins with depleted beta cells that leads to insulin resistance?

Answer 2

False

It begins with insulin resistance that eventually leads to beta cell depletion due to the constant production of insulin

Question 3

Hyperglycemia affects…

Answer 3

Tissues of the body including blood vessels and nerves

Question 4

TRUE OR FALSE

An increase in insulin resistance leads to increased insulin production?

Answer 4

True

It is a compensatory mechanism which is why glucose levels initially remain stable

Question 5

Does obesity cause T2D?

Answer 5

No but they are highly associated. The reason for the association is unknown

Question 6

Which 3 major metabolic defects does hyperglycemia result from?

Answer 6

1. Liver - increased hepatic glucose production
2. Pancreas - impaired glucose secretion
3. Adipose - insulin resistance

Question 7

Explain EdU labelling

Answer 7

Incubate cells with EdU (an analogue of thymidine) and they are incorporated into cells synthesising DNA AKA proliferating cells.

Question 8

What were the main findings of the Hill paper?

Answer 8

In germ free environment there is no increase in b-cells during development. BefA protein release by bacteria restored the b-cell population by increasing the number of proliferating b-cells (shown by EdU labelling).

Question 9

Explain the evidence that adenosine signalling plays a role in b-cell regeneration

Answer 9

Double transgenic fish to selectively ablate (NTR-MTZ) b-cells and visualise them. Treat fish with different drugs to see which drugs restored b-cell populations. All drugs that had an effect acted on the adenosine signalling pathway.

Question 10

What is leptin?

Answer 10

A hormone made by adipocytes. Released after eating, makes us feel full

Question 11

What happens in a leptin KO mouse?

Answer 11

They are obese, diabetic, infertile and hypoactive

Question 12

Where are leptin neurons found?

Answer 12

In the arcuate nucleus of the hypothalamus (near the third ventricle of the brain)

Question 13

NYP neuron

Answer 13

• INHIBITED BY LEPTIN

- When stimulated neurons increase food intake

Question 14

POMC neurons

Answer 14

• STIMULATED BY LEPTIN

- When stimulated, food intake increases