Regulation of plasma glucose Flashcards
What is the normal range of plasma glucose?
100 mg/dL
5.5 mmol/L
What is hypoglycemia?
A drop in blood glucose
What happens to the body during hypoglycemia?
Different organs have different dependencies on glucose
Brain - requires continuous glucose supply, very sensitive to changes - main source of energy for neural cells
Heart - can produce energy from fatty acids
Liver - hepatocytes have glycogen storage and can catalise metabolites to make ATP - not sensitive to glucose changes
Muscle - glycogen is primary fuel - large storage of glycogen
What happens to the brain during hypoglycemia?
A limited amount of glucose can be derived from the glycogen stored in astrocytes - consumed within minutes
cognitive dysfunction -> seizure -> coma
What is hyperglycemia?
High blood glucose
Normal if transcient
If prolonged - complications
What are the short term complications from hyperglycemia?
Increased urine output
Thirst
Ketoacidosis
What are the long term complications from hyperglycemis?
Atherosclerosis
Kidney failure
Eye complications
Diabetic foot ulcer
How is glucose in the plasma maintained?
Exchanged between the cytoplasm and the extracellular fluid
Can glucose pass through the membrane by diffusion?
NO
What facilitates trasfer of glucose into cells?
Carrier proteins
What are the different types of carrier proteins found in cells?
GLUT - 1
GLUT - 2
GLUT - 3
GLUT - 4
Where is the carrier protein GLUT-1 found?
Brain and RBC
Where is the carrier protein GLUT-2 found?
Liver, pancreas and intestine
Where is the carrier protein GLUT-3 found?
Brain and kidney
Where is the carrier protein GLUT-4 found?
Muscle and adipose tissue