B5-045 Renal Physiology V Flashcards
what part of the tubule
- reabsorption of solutes/fluid
- secretion of organic anions/cations
proximal tubule
what part of the tubule
reabsorption of Na+, Cl-, K+
ascending loop of Henle
what part of the tubule
- reabsorption of Na+, Cl-, and water
- secretion of K+ and H+
2
distal tubule
collecting duct
[…] is required to drive all transporters in the proximal tubule
sodium
what part of the tubule
all transport depends on NaKATPase
proximal
what part of the tubule
glucose, amino acids, and phosphate are absorbed by apical Na+ cotransporters
proximal
what part of the tubule
protons are secreted by Na+ proton exhanger
proximal
what part of the tubule
chloride follows the paracellular pathway and base-dependent exchanges
proximal
what part of the tubule
organic anions are secreted by Na-dependent and independent OAT transporters
proximal
transport defects in the proximal tubule result in a kidney reabsorptive condition called
Fanconi syndrome
- polyuria, polydipsia, and dehydration
- hypophosphatemic rickets/osteomalacia
- growth failure
- metabolic acidosis
Fanconi
symptoms vary depending on extent
- hypokalemia
- hyperchrolemia
- hypophosphatemia, phosphaturia
- glucosuria, aminoaciduria
Fanconi
symptoms vary depending on extent
environmental causes of Fanconi syndrome
- heavy metals (lead)
- tetracyclins, gentamycin
- toluene (paint/dyes)
what part of tubule
Na+, K+ and Cl- are co-transported in the apical side by NKCC
ascending loop of Henle
what part of tubule
K+ and Cl- are absorbed together at the basolateral side or independently through channels
ascending loop of Henle
what part of tubule
K+ also leaks to the tubular side via ROMK1, helps with K+ recycling and maintains function of NKCC2
ascending loop of Henle
transport defects in the ascending loop of Henle depend on alterations in […], […], and […]
ROMK1
NKCC2
Barttin
Bartter’s syndrome
- polyuria, polydipsia
- poor muscle tone
- heart repolarization abnormalities
Bartter’s syndrome
- hyponatremia
- hypokalemia
- hypochloremia
- ECF volume contraction
- high renin aldosterone
- metabolic alkalosis
Bartter’s syndrome
environmental causes of Bartter’s syndrome
furosemide and bumetanide
inhibit NKCC2
malfunction of the countercurrent mechanism in Bartter’s syndrome causes
polyuria/polydipsia
malfunction of the NKCC, ROMK1, and Cl channels in Bartter’s syndrome causes
solute diuresis
wasting of Na+, K+, Cl-
malfunction of the juxtaglomerular apparatus in Bartter’s results in
hyper-reninemia, high aldosterone, alkalosis
activates proton pumps
hormone
aldosterone
treatment of Bartter’s
- postassium supplement
- aldosterone antagonists
- ACE inhibitors
- NSAIDs
- Ca+ and Mg+ supplements
- growth hormone
what part of tubule
Na+ and Cl- are cotransporterd in the apical side and reabsorped basolaterally
distal tubule
what part of tubule
K+ is secreted to the tubular fluid via K+ channels
distal
what part of tubule
Ca2+ is reabsorbed via channels and the basolateral Na/Ca exhanger
distal
transport defects in the distal tubule are due to mutations in […] or [..]
- TSC (Na/Cl exchanger)
- TRPM6 (magnesium)
- hyponatremia
- hypokalemia, high urine K+
- hypomagnesemia, high urine Mg+
- hypocalciuria
- ECF volume contraction
- normotensive
Gitelman’s syndrome
environmental cause of Gitelman’s
thiazide OD
what part of tubule
Na+ is reabsorbed apically by ENAc
collecting duct