w2- metabolic consequences of kidney failure Flashcards
what are the principle substrates for gluconeogenesis
lactate, the amino acids alanine & glutamine, and glycerol
what contributes to the circulating glucose during an overnight fast, late into a fast, and in the post- prandial state
After an overnight fast, glucose release via gluconeogenesis is about equal from liver & kidneys, although total glucose yield from liver is greater because it also performs glycogenolysis.
As fasting continues, and the contribution of liver glycogenolysis declines, the proportion of all the glucose released into the circulation coming from the kidneys increases- about equal liver and kidney In the
post-prandial state, glycogenolysis & gluconeogenesis in liver both decrease, but in kidneys gluconeogenesis increases 2x. It accounts for 60% of endogenous glucose release in the post-prandial period.
what would be the consequences of renal failure to arginine and NO synthesis
kidney synthesizes the majority of arginine and also contributes to NO synthesis
since the arginine is converted into citriline in the small intestines and then uncovered by the kidney into arginine, without the kidney all of the urea would be converted to urea by the liver
why would melanin and NE production be decreased in CKD
kidneys make tyrosine by hydroxylating phenyalanine
Where is ammonia in the kidney produced
PCT
what does the kidney use glutamine for
glutamine is made into ammonia –> used to buffer acidity and decrease uric acid stones
glutamine –> glutamate –> alpha keto
the above rxn yels alpha ketoglutarateàCo2 àbicarb to also buffer
what is the kidneys response to acidemia
increase ammonia
increase bicapb
hypertrophy due to decreased protein degredation
what kind of anemia is caused by CKD?
what is a TX
normocytic (normal MCV), normochromic (normal concentration of hemoglobin in red cells) and hypoproliferative anemia
EPO - if dont respond then add iron
what is the preferred energy source for the kidney
ammonia
define Cachexia
degrade more proteins (increased proteosome activity) than regularly and this is then complicated by anorexia and the down reg of protein synthesis
Increased by acidemia whichincreases proteasome activity
Increased by inflammation
Downregulation of protein synthesis due to insulin resistance
Result in negative nitrogen balance
what happens to leptin in CKD
increased –> limits appetite
ID the role of hepcidin
Iron availability is controlled by the liver hormone, hepcidin
Hepcidin lowers dietary iron absorption and macrophage iron recycling from senescent red cells and this is elevated in CKD
