Enzyme-Linked Receptors Flashcards
ANP
Atrial Natriodiuretic Peptide
Atrial = heart Nartio = sodium diuretic = causing increased passing of urine
Helps to reduce heart rate back to normal
ANP Receptor
- single membrane spanning protein
- has extracellular receptor binding domain
- intracellular guanylyl cyclase domain that is inactive as a monomer
IDD: Insulin Deficient Diabetes Mellitus
- High blood glucose
- defective pancreatic beta cells
- insufficient insulin secretion
- low insulin levels
- treated with insulin
IRD: Insulin Resistant Diabetes Mellitus
- High blood glucose
- defective insulin receptors/signaling in peripheral tissues
- increased insulin resistance
- normal or high insulin levels
- treated with insulin
Diabetes
Presentation:
- weight loss
- polydipsia/polyuria
- weakness
Pathology:
- hyperglycemia
- glucosuria hyperlipemia
- ketouria
- uremia
Diabetes: Failure to take up glucose
Hyperglycemia:
-exceed renal threshold -> glucosuria
- hyperosmotic plasma ->dehydration of cells -> hyperglycemic coma
- polydipsia -> osmotic diuresis -> polyuria
Diabetes: Intracellular Energy Shortage
Mobilization of fatty acids -> hyperlipemia
Metabolism of fatty acids:
- acetyl-CoA -> acetacetate -> 4-OH butyrate + acetone
- keto acidosis -> acidotic coma
- ketouria
Amino acid metabolism -> urea production -> uremia
Normal resting plasma glucose
4-6 mM
Normal plasma glucose after eating or excitement
14-17 mM
Diabetic plasma glucose
22-44 mM
Erythropoietin in Medicine, Sports, and Doping
- Erythropoietin (EPO) produced mainly by kidneys
- Production is stimulated by reduction in oxygen partial pressure (ex- low erythrocyte counts or at high altitude)
- EPO increases number of erythocytes by stimulating proliferatin of erythrocyte progenitor cells in bone marrow
- Failing kidney may not be able to produce sufficient amount of EPO.
- Low endogenous EPO levels can be treated by giving recombinant human EPO (rhEPO) = can dramatically improve status of sick animal or human by boosting O2 delivery to all tissues
- Misuse of EPO has serious side-effects = increase in RBC numbers increases blood viscosity and poses serious risk of embolism
T/F: A patient treated with rhEPO for long enough periods of time may have reductions in their natural ability to make EPO.
True.
The body becomes dependent on the treatment and degrades its own production.
Describe the structure of the Receptor Tyrosine Kinases
- two extracellular subunits containing the hormone binding domains
- two membrane spanning subunits containing the tyrosine kinase domains
Describe the structure of Tyrosine-kinase associated receptors
single membrane spanning protein with an extracellular hormone binding domain
