5 - Inroduction to Diabetes Mellitus Flashcards
Name the 2 mechanisms of insulin to decrease the blood glucose concentration
- decreased hepatic glucose output
- increase uptake of glucose by muscles
How does insulin increase protein conc in the blood?
decreased proteolysis
Name the 2 mechanisms of insulin to decrease the blood lipid concentration
- decreased lipolysis
- decreased ketogenesis
What are the other mitogenic affects insulin?
- growth
- vascular effects - smooth muscle hypertrophy
- ovarian function
- clotting
- energy expenditure
The majority of glucose transporters (e.g. GLUT-4) are insulin sensitive. Which ones are not?
brain, liver, RBCs, pancreas
Where are the GLIT-4 transporters mostly found?
on the surface of muscle cells and adipose tissue
What re the element of the GLUT-4 receptor?
hydrophobic elements on the outside and a hydrophilic core which allow for glucose to pass through
What effect does insulin have on GLUT-4?
GLUT-4 is recruited from vesicles in the cytoplasm to the membrane (causes a 7 fold increase in glucose uptake)
What is the more specific effect of insulin on protein in muscle cells?
prevents oxidation of amino acids
increases re-synthesis of proteins from amino acids
What four hormones have a contradicting effect to insulin?
somatotrophin
cortisol
catecholamines
glucagon
NOTE: somatotrophin and cortisol have contradicting effects
What is the effect of insulin on the liver?
- stimulates protein synthesis
- inhibits gluconeogenesis
What is the effect of glucagon on the liver?
- increases uptake of amino acids
- increases gluconeogenesis
(this includes somatotrophin, cortisol and catecholamines aswell) - increase hepatic glucose output
What is the effect of insulin on adipocytes?
(triglycerides come from the blood, but are too big to enter the adipocytes directly)
- insulin stimulates LIPOPROTEIN LIPASE - break the TAGs down so they can be absorbed
What is the effect of insulin and the 4 counter regulatory hormones on lipolysis?
insulin stops lipolysis
What molecules are ketone bodies synthesised from?
Where in the body are they synthesised?
fatty acids
in the liver
How is glucose converted into glycogen?
Which hormones promotes this?
- glucose enters the liver
- glucose ——> glucose-6 phosphate
- glucose-6 phosphate ——> glycogen
insulin
