Term
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Definition
Iso-osmotic reabsorption
25% Mg
70% Na, Cl, Ca
80% HCO3 via CA, PO4
90% K |
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Term
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Definition
| Symporter w/ Cl, glucose, aa |
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Term
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Definition
Symporter w/ Na
Antiporter w/ organic bases
Paracellular |
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Term
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Definition
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Term
| Plasma protein concentration in peritubular capillaries is dependent on... |
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Definition
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Term
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Definition
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Term
| Li is mainly reabsorbed in the... |
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Definition
PT
Hydrated Li ion ~same charge/volume ratio as hydrated Na, so acts as Na in the transport systems |
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Term
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Definition
Organic acids like PAH, diuretics, penicillins
Organic bases like Cr, formate, diuretics |
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Term
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Definition
| Water reabsorbed, NaCl left behind in lumen = U-osm inc. |
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Term
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Definition
Salt reabsorbed, water left behind in lumen = U-osm dec.
25% Na, Cl, Ca (b/c K secretion into tubule forces the Ca, Mg inward)
75% Mg
Rest of K (pretty much no K gets to DT) |
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Term
| Thick AL reabsorption of NaCl is important because... |
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Definition
It determines if the urine is dilute or concentrated
NaCl reabsorption creates hyperosm interstitium that drives water reabsorption w/ ADH |
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Term
| Macula densa marks the transition from... |
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Definition
| The ascending limb to the early DT |
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Term
| Macula densa is in close contact with... |
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Definition
| The vascular pole of the glomerulus, JG cells of afferent arteriole |
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Term
| The purpose of the macula densa is... |
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Definition
To monitor Na load as [NaCl] x flow rate
Uses NaK2Cl symporter |
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Term
| What does an increased Na load mean to the macula densa? |
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Definition
Reabsorptive capacity of PT, thick AL have been exceeded
Continued filtration at the existing rate would cause Na wasting and hypovolemia |
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Term
| How does the macula densa tell anyone to do anything? Who does it tell? |
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Definition
Adenosine/ATP message to afferent arteriole causing VC (suppressed, VD if opposite)
Afferent arteriole hydrostatic P dec.
Filtration and urinary flow rate dec.
More efficient reabsorption of Na in PT and thick AL |
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Term
| How is renin secretion related to the NaCl load sensed by the macula densa? |
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Definition
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Term
| So the macula densa senses low Na. What does renin do? |
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Definition
Body needs to in.c BP/EABV
Renin secretion inc.
AngII inc., stim aldosterone, enhances Na reabsorption/K secretion
AngII also stim thirst and ADH release
Isotonic expansion of plasma vol. |
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Term
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Definition
Salt reabsorbed, water left behind in lumen = U-osm dec.
5% Ca (PTH), Mg
10% Na, Cl via symporter
20% HCO3 via CA |
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Term
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Definition
90% principal cells: reabsorb Na 2-4% and H2O, secrete K
10% intercalated cells: secrete H |
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Term
| Describe the movement of Na in the principal cell |
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Definition
Basolateral Na-K ATPase creates dec. ICF Na
Na leaves lumen and enters cell via ENaC
Makes lumen electronegative
Drives out K from cell into lumen, pulls Cl paracellularly from lumen to interstitium |
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Term
| Any diuretic that inc. delivery of Na to the DT... |
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Definition
| Increases the urinary loss of K, H |
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Term
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Definition
Binds to cytoplasmic R
Inc. mito production of ATP
Inc. activity of basolateral Na-K ATPase
Inc. number of ENaC
Inc. H secretion
Indirectly inc. K secretion |
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Term
| Any diuretic that causes plasma volume contraction diuresis produces... |
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Definition
Inc. RAAS activity
Secondary aldosteronism
Hypokalemia |
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Term
| Diuretics inc. K secretion from LDT/CD because... |
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Definition
Inc. Na sent to LDT/CD causes inc. rate of Na reabsorption/K secretion
Na depletion inc. RAAS activity, causing inc. aldosterone and thus Na reabsorption/K secretion |
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Term
| How does a dec. in renal perfusion pressure cause FF to inc.? |
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Definition
RBF falls more than GFR = FF inc.
Na, H2O retained |
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Term
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Definition
| Diuresis b/c peritubular plasma protein concentration is dec. and so lots of the reabsorbed Na, H2O actually leak back to the tubule |
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Term
| Drugs that cause a low FF and diuresis |
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Definition
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Term
| Conditions/drugs that cause an inc. FF and oliguria |
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Definition
| CHF (reversed w/ digoxin) |
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Term
| What is the primary use of diuretics? |
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Definition
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Term
| What determines the desired rate of diuresis? |
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Definition
Location of excess fluid
Interstitial space: rapidly equilibrates w/ plasma volume, so rapid diuresis of plasma won't cause hypovolemia b/c the fluid will move out of the interstitium and into the plasma
Loculated (ascites): diuresis has to be done slowly b/c this compartment equilibrates slowly w/ plasma volume |
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Term
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Definition
Filtered and secreted into tubule via organic acid transport system
Inhibits CA
35% of PT reabsorption of HCO3 inhibited
Na and thus H2O PT reabsorption inhibited
Loop takes out Cl but not permeable to HCO3, so Na has to stay in lumen
Urinary pH inc. to 8.2
Inc. K secretion |
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Term
| Bumetanide, ethacrynic acid, furosemide, mannitol: MOA |
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Definition
| Dec. Na reabsorption in thick AL |
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Term
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Definition
| Dec. Na reabsorption in EDT |
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Term
| Amiloride, spironolactone, triamterene: MOA |
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Definition
Dec. Na reabsorption in LDT, CD
K-sparing |
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Term
| Acetazolamide: indications, S/E |
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Definition
Glaucoma, altitude sickness (prophylaxis), alkalinize urine to inc. loss of toxic acidic drug (like ASA)
Hyperchloremic metabolic acidosis b/c getting rid of HCO3, retaining Cl, and impairing H secretion |
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Term
| Amiloride, triamterene: indications, S/E |
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Definition
K-sparing
Use w/ loop diuretic like thiazide to enhance Na loss but lessen hypokalemia
Amiloride: CF inhalation slows mucus accumlation and inc. its clearance from lungs
Hyperkalemea: don't give w/ K supplements and be careful w/ severe renal insufficiency! |
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Term
| Amiloride, triamterene: MOA |
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Definition
Block principal cell ENaC in DT, CD
Inc. excretion of Na, Cl, H2O, HCO3
Inhibit secretion of H
Dec. secretion of K
Natriuresis not dep't on presence of aldosterone
Weak diuretic! |
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Term
| Loop diuretic + metolazone: indication |
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Definition
For pt who haven't responded to loop diuretic b/c avid proximal reabsorption of Na
Combo allows for massive Na, K loss
Need to monitor! |
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Term
| Spironolactone: MOA, duration of action |
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Definition
Blocks aldosterone R in DT
Inc. excretion of Na, Cl, H2O, HCO3
Dec. excretion of K
Long t1/2 = 24 hrs |
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Term
| Spironolactone: indications, S/E |
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Definition
K-sparing
Use w/ loop diuretic like thiazide to enhance Na loss but lessen hypokalemia
Refractory edema, CHF (dec. LV wall stiffness), nephrotic syndrome and cirrhosis (b/c intravascular hypovolemia causes secondary hyperaldosteronism and K loss)
Hyperkalemea: don't give w/ K supplements and be careful w/ severe renal insufficiency!
Partial androgen/estrogen/progesterone agonist, inhibits CYP17 = inhibits testosterone synthesis: menstrual irregularity, hirsutism, gynecomastia, azoospermia |
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Term
| Mannitol: properties, effect on diuresis |
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Definition
Ascending loop of Henle
Freely filtered, not reabsorbed, metabolically inert
Inc. urine flow rate up to 10 ml/min and excretion of Na, Cl, HCO3, K, Ca, Mg, PO4
magnitude of loss is directly proportional to amt of mannitol in urine |
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Term
| Mannitol: method of admin, indications, S/E |
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Definition
IV
Dec. ICP if not due to bleeding
Prevent complete renal failure in pt w/ AKI
Prevent toxicity of cisplatin, ampho B, cyclosporine, Mb
Dec. IPO in glaucoma
Overexpansion of intravascular volume causing pulmonary edema, CHF
Hyponatremia, headache, nausea |
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Term
| Bumetanide, ethacrynic acid, furosemide: properties, indications |
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Definition
Filtered, secreted into PT via organic acid transport system (oral or IV)
Activity not affected by pH
Rapid diuresis of short duration Effective if GFR <25 ml/min
Acute pulmonary edema
Management of edema in cardia, hepatic, renal diseases
Hypercalcemia |
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Term
| Bumetanide, ethacrynic acid, furosemide: MOA |
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Definition
Inhibit NaK2Cl symporter in medullary/cortical loop of Henle
Dec. reabsorption of NaCl, Ca, Mg
Inc. urate reabsorption
Huge natriuresis (and subsequent inability to make a dilute or concentrated urine b/c no osmotic gradient)
Inhibit NaK2Cl symporter in macula densa
Block TG feedback and immediate inc. GFR and inc. renin secretion (subsequent AngII inc. causes secondary hyperaldosteronism)
Stim renal synthesis of PG which inc. RBF, GFR
Inc. Na delivery to DT, inc. flow, and secondary hyperaldosteronism cause inc. K secretion (administered KCl can correct the hyperaldosteronism-induced metabolic alkalosis)
Also inc. HCO3 and PO4
Furosemide can inhibit CA in large doses and thus inhibit Na reabsorption in PT |
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Term
| Bumetanide, ethacrynic acid, furosemide, thiazides: S/E |
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Definition
Secondary hyperaldosteronism
Hypokalemia hypochloremic metabolic acidosis from excess loss of NaCl and KCl
Hypomagnesemia: cardiac dysrhythmias
Hyperuricemia: gouty arthritis
Orthostatic hypotn from vol. depletion
Dilutional hyponatremia from inability to excrete excessive water intake
Azotemia, coma in severe renal and hepatic disease
Ethacrynic acid: tinnitus and reversible hearing loss w/ large doses
Furosemide: hyperglycemia |
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Term
| HCTZ, metolazone: properties |
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Definition
Secreted into PT via organic acid transport system (oral), reduce GFR, effect on RBF is variable
Metolazone more efficacious that HCTZ b/c inhibits Na reabsorption in PT too
But less efficacious than loop diuretics!
Activity not affected by pH
Rapid diuresis of long duration
HCTZ: ineffective if GFR <25 ml/min, metolazone just fine if GFR <25 |
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Term
| HCTZ, metolazone: indications |
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Definition
HTN
Edema due to CHF, mild renal failure, cirrhosis, premenstrual weight gain, hormone therapy w/ estrogen
Hypercalciuria in pt w/ renal calcium stones
DI: natriuretic dec. in plasma vol. inc. the efficiency of salt/water reabsorption in PT, less vol. sent to CD |
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Term
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Definition
Inhibit active NaCl reabsorption in DT
Progressive ECF volume contraction causes activation of RAAS and secondary hyperaldosteronism
Hypertonic urine (can't make a dilute urine)
Inc. urate reabsorption in PT
Inc. excretion of K, Mg
Dec. excretion of Ca
Thiazides can inhibit CA at larger doses, urinary pH rises to 7.4 |
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