introduction to diabetes Flashcards
1
Q
- In which cell types are GLUT-4 transporter proteins most commonly found?
- Do GLUT-4 transporter proteins respond to insulin?
A
Common in myocytes and adipocytes
Yes
2
Q
- How does insulin affect proteolysis and protein synthesis respectively in myocytes?
A
Inhibits proteolysis as protein is not needed as a fuel source
Stimulates protein synthesis to use the proteins for storage
3
Q
- What effect does GH and IGF-1 have on protein synthesis in myocytes?
- What effect does cortisol have on proteolysis in myoctes?
- What is a gluconeogenic amino acid?
A
Stimulates it
Stimulates it An amino acid that can be converted into glucose through gluconeogenesis
4
Q
- What hormone leads to an increase in uptake of gluconeogenic amino acids in the liver?
- What role does glucagon have in the liver?
A
Glucagon
Stimulates proteolysis to produce more gluconegenic amino acids These amino acids are then converted into glucose in gluconeogenesis which is also stimulated by glucagon (as well as cortisol)
5
Q
- What effect does insulin have on the hepatic glucose output in the fed state?
A
It reduces hepatic glucose output
Because it inhibits gluconeogensis So less glucose is synthesised
6
Q
- What does Lipoprotein Lipase break Triglycerides down into to be absorbed into adipocytes and what hormone is this process stimulated by?
A
Glycerol and Non-Esterified Fatty Acids (NEFA)
Insulin
7
Q
- What does Insulin do in the adipocytes?
A
Increases uptake of glucose via GLUT-4
Converts Glycerol and NEFA into triglycerides again for later use when needed - lipogenesis Also uses glucose as a substrate for the re-synthesis of triglyceride (due to glycolysis, acetyl Co A produced, converted into fatty acids), instead of NEFA to reduce glucose levels Thereby inhibiting the breakdown of triglycerides in the adipocytes back into NEFA and Glycerol
8
Q
- What effects does GH and Cortisol have on the triglycerides in the adipocytes in the fasting state?
- In the fasting state what happens to the glycerol taken up by the liver?
A
Stimulates breakdown of triglycerides into Glycerol and NEFA to be used as an alternative energy source once transported into the liver - stimulates lipolysis
It is converted into glucose in process, gluconeogenesis Increasing hepatic glucose output
9
Q
- In the fed state what happens to the glycerol taken up by the liver?
- Can the brain utilise NEFA as a fuel?
- What can the brain use as a fuel?
A
Converted into triglycerides
no
Glucose, Ketone Bodies
10
Q
- In the fed state, what does insulin do once NEFA is uptaken by the liver?
A
NEFA converted into fatty Acyl-CoA
Insulin inhibits the conversion of Fatty Acyl-CoA into ketone bodies This prevents it from being used as an alternative metabolic substrate to glucose The opposite happens in the fasting state where ketone bodies are produced
11
Q
- What does it mean if there is a high level of ketones and glucose?
- In the fed state what happens to glucose in the liver?
A
There is an issue with insulin secretion#
It is converted into Glucose-6-P This is then converted into Glycogen (stimulated by insulin)
12
Q
- In the fasting state what happens to glycogen in the liver?
- In the fed state what happens to Glucose in myocytes?
A
It is broken down (process stimulated by glucagon) - Glycogenolysis
It is converted into glycogen to be stored and used when the myocyte needs energy It is also used in aerobic respiration
13
Q
- What effect does Glucagon and GH have on the GLUT-4 transporters in myocytes?
- In the fasting state why is amino acid concentration increased initially and then decreased when prolonged?
A
Inhibits uptake of glucose via GLUT-4 to allow more glucose to remain in circulation and increase the blood glucose levels
Increased due to increased proteolysis and then decreased due to more gluconeogenesis to increase hepatic glucose output
14
Q
- What tests can be carried out to make a diagnosis of diabetes?
A
Fasting glucose > 7.0mmol/L
Random glucose > 11.1mmol/L Oral glucose tolerance test HbA1c (>48mmol/L)
15
Q
- How many tests do you need to diagnose diabetes?
A
2 positive tests
Or 1 positive test and symptoms
