The endocrine Pancreas

Question 1

What does SGLTs mean?

Answer 1

Sodium-Glucose cotransporters

Secondary Active transport

Question 2

SGLT 1

Answer 2

Glucose Absorption from the gut

Question 3

SGLT1, SGULT2

Answer 3

Glucose reabsorption from the kidney (PCT)

Question 4

GLUT 1

Answer 4

Brain, erythrocytes - a high affinity for glucose: constant uptake of glucose at 2-6 mM

Question 5

GLUT2

Answer 5

Liver, kidney, pancreas, gut- low-affinity- glucose equilibrates across the membrane

-Glucose-dependent insulin release in the pancreas

Question 6

GLUT3

Answer 6

Brain - high affinity

Question 7

GLUT4

Answer 7

Muscle and adipose - a medium affinity. Insulin recruits transporters
-Insulin-dependent uptake of glucose into cells

Question 8

Islets of Langerhans

Answer 8

Clusters of endocrine cells surrounded by exocrine pancreas

Question 9

alpha- cells

Answer 9

Glucagon

Question 10

Beta cells

Answer 10

Insulin

Question 11

Delta cells

Answer 11

Somatostatin

Question 12

How is insulin made?

Answer 12

Pre-pro insulin - signal sequence removed - proinsulin (in the rough endoplasmic reticulum)
Transfer to Golgi apparatus- peptidases break off the C peptide leaving an A and B chain linked by disulfide bonds
One mole of C-peptide is secreted for each molecule of insulin

Question 13

What arteries supply the pancreas?

Answer 13

Ceoliac, superior mesenteric, and splenic arteries

Question 14

Where does venous drainage of the pancreas go to?

Answer 14

The portal vein

Question 15

Where is half of the insulin metabolised?

Answer 15

By the liver

Question 16

How do beta cells detect a rise in glucose?

Answer 16

There are no glucose receptors so GLUT2/glucokinase can be thought of as the sensor.
Effector is rise in ATP due to glucose oxidation

Question 17

What family is the insulin receptor in?

Answer 17

Tyrosine kinase superfamily

Question 18

What happens when insulin binds to the insulin receptor?

Answer 18

• Activates a cascade of protein phosphorylation, which stimulate or inhibit specific metabolic enzymes by modulating enzyme phosphorylation.
• Modulates the activity of metabolic enzymes by regulating gene transcription

Question 19

Type 1 classification diabetes mellitus

Answer 19

Absolute insulin deficiency (due to destruction of insulin-producing pancreatic beta cells)

Question 20

Type 2 classification diabetes mellitus

Answer 20

Variable combination of insulin resistance and insulin insufficiency

Question 21

What fasting concentration of plasma glucose indicates diabetes?

Answer 21

> /= 7.0 mmolL-1

Question 22

What % is good for glycaemic control?

Answer 22

6.5%

Question 23

Treatment for type 2 diabetes

Answer 23

Metformin: decreases gluconeogenesis
Sulfonylureas: Bind and close KATP channels, depolarize B cells releasing insulin
Thiazolidinediones: activate PPARgama receptor (controller of lipid metabolism), which reduces insulin resistance
SGLT2 inhibitors: promote glucose excretion via kidney
Incretin targeting drugs: potentiate insulin release in response to rising plasma glucose

Question 24

What does DPP-4 inhibitors

Answer 24

Prevent breakdown of natural incretins