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11 Cards in this Set
- Front
- Back
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How is Liddle's SYndrome caused? |
Autosomal dominant inheritance Mutation in genes for ENaC (Principal cell - renal) |
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What occurs in Liddle's syndrome? |
Na and fluid retention -excessive Na and H2O uptake (ENaC), Leads to expansion of ECF, Hypertension
Hypokalaemia. -abs excess Na (ENaC) drives Vm towards Ena, drives exit of Na and entrance of K (Na/K ATPase)
Metabolic alkalosis. alpha-intercalated cell, increased Na abs = driving force for secretion of H = increase pH
Low renin and aldosterone levels |
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How would the body normally decrease BP? |
BP rises: decreased renin and aldosterone release low aldosterone reduces trafficking of ENaC decreased Na reabs so decreased H2O reabs so decreased BP |
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How would the body react to an increase in BP in an individual with Liddle's syndrome? |
BP rise: decreased renin and aldosterone release but faulty compensation mechanism so can't remove ENaC from membrane No reduction in Na reabs Hypertension persists |
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What is the treatment for Liddle's syndrome? |
Amiloride K+ sparing diuretic blocks ENaC |
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Why does spironolactone not work as a treatment for Liddle's syndrome? |
It's a mineralcorticoid R antagonist (MR R binds aldosterone) Not effective b/c aldosterone already low |
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What are the symptoms seen in diabetes insipidus? |
Polyuria increased flow rate upto 23L in 24hrs
Compensatory polydipsia thirst dehydration can be a serious issue
Hypernatremia high Na |
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What are the 4 types of diabetes insipidus? |
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What are the causes of central diabetes insipidus? |
1. Acquired infection in brain head trauma surgery 2.Congenital neurohypophyseal DI 67 mutations in AVP gene (production/ function/ trafficking) |
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What are the causes of nephrogenic diabetes insipidus? |
1.Acquired lithium -bipolar affective disorder treatment. Toxic to kidney. Some antibiotics, antifungals, antineoplastic (chemo) agents Hypokalemia and hypercalciuria Acute and chronic renal failure
2.Congenital mutations in AVPR2/AQP2 genes AVPR2 gene -X-linked -impacts on trafficking(dominant) or function (recessive) of protein |
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What are the treatments of diabetes inspidius? |
1.Central Desmopressin increases urine osmolality 2.Nephrogenic - difficult as defect lies in kidney so can't respond Possibilities: Modulator drugs - corrects misfolding Pharmacological chaperones - push misfolded proteins to membrane (AQP2) Cell permeable R antagonists (cGMP and cAMP pathway antagonists - traffick AQP2) Statins Prostaglandins Heat shock protein 90 |
