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
