Nitrogen Metabolism Flashcards
What are struvite crystals related to
Bacterial infections
What is calcium oxalate related to
Hyperparathyroidsim
What is the first step in nitrogen removal
Oxidative deamination
What holds the nitrogens to get removed
Glutamate
what is the carbon source for transamination reactions
Aspartate
What is the rate limiting step of urea cycle
Conversion of ammonia and carbamoyl phosphate via carbamoyl phosphate synthetase and NAG activation
Where is nitrogen removed in the kidney
PCT
Hartnup and cystinuria are diseases related to ….
H- reuptake of nonpolar AA
C- reuptake of dibasic AA
Why are Hartnup and Cystinuria double whammy effects
Because they have both the reuptake issue in the kidney but they also have the uptake issue in the intestines
What is the MoA of Hartnup and Cystinuria
Deficient membrane transporters
Hartnup is devastating when looking at one particular AA, which one causes the most issues?
Trp
It is used for NT and niacin (energy production)
What is a classic symptom of hartnup
Pellagra-like dermatosis
What causes a Hartnup event
Sunlight, fever, drugs, emotional or physical stress, or poor nutrition
What is the treatment for hartnup disease
Niacin repletion and includes a high-protein diet
What is niacin or B3 also called
Nicotinic acid
What tissues need niacin more
Tissues that have high energy demands or tissues that have a high turnover rate
What are the dibasic AA
COAL Cystine Ornithine Arginine Lysine
What are the symptoms of cystinuria
Renal colic related to the stones
How do we diagnose cystinuria
Nitroprusside test
What is the transporter that can help with uptake/reuptake issues
PEPT1 can take up peptides
Secondary PKU is an issue with what enzyme
Dihydrobiopterin reductase
What enzyme is affected in classic PKU
Phenylalanine hydroxylase
What defective enzyme is responsible for albinism
Tyrosinase
Tyrosine—> melanin
What is the most common IEM
PKU
What are the symptoms of PKU? Treatment?
Musty odor in urine cause by phenylacetate (also blocks AA transport and neurotransmission in the brain)
Limit Phe and supplement Tyr
When is it critical to have diagnosed PKU
Before 2 weeks
What is the upper limit of Phe in the blood
6 mg/dL
What helps with PKU in diet
Treatment of tetrahydropiopterin (5-20mg/kg a day)which is a PAH cofactor
What enzyme is linked to type 1 tyrosinemia
Fumaraylacetate hydrolase
What is a main symptom of type 1 tyrosinemia
Cabbage smelling urine
What enzyme is related to type 2 tyrosinemia
Tyrosine aminotransferase
What is the inheritance of alkaptonuria
Autosomal recessive
What do we find with alkaptonuria
Black intervertebral disks and urine
What triad is associated with alkaptonuria
Homogenistic aciduria, ochronosis, and arthritis
