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Case 8: Diabetes Insipidus

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renal physiology

Text of Case 8: Diabetes Insipidus

Case Special ConferenceCase 8: Diabetes Insipidus

38. 51460612 . 51460629 . Tenzin Thoesam 50461283

Case 8: Diabetes Insipidus 19 (Polyuria) 5 (Polydipsia) 105/70 mmHg (Heart rate,HR) 85 /

PlasmaNa+ Osmolarity 147 mEq/L (normal 140 mEq/L) 301 mOsm/L (normal 290 mOsm/L)

Urine70 mOsm/L Negative

Glucose (fasting) 90 mg/dL (normal 70-100 mg/dL)

2 (a 2- hour water deprivation test) Plasma osmolarity (mOsm/L) Urine osmolarity (mOsm/L) 301 325

70

70

dDAVP (vasopressin or antidiuretic hormone, ADH) Plasma osmolarity (mOsm/L) Urine osmolarity (mOsm/L) dDAVP dDAVP 325 70 290 500

Diabetes insipidus

dDAVP

1 urine osmolarity

Urine osmolarity1. With normal diet and fluid intake: 500-800 mOsm/L 2. Range: 50-1,200 mOsm/L

Plasma osmolarity ADH Secretion

H2O reabsorption Urine osmolarity & urine volume Plasma osmolarity

Plasma osmolarity ADH Secretion

H2O reabsorption Urine osmolarity & urine volume Plasma osmolarity

2 (primary polydipsia )

2 (a 2- hour water deprivation test) Plasma osmolarity (mOsm/L) Urine osmolarity (mOsm/L) 301 325

70

70

( Primary polydipsia )

3 polyuria polydipsia

Diabetes mellitus The high levels of glucose in plasma Glucose is found in the urine Polyuria Polydisia

PlasmaNa+ Osmolarity 147 mEq/L (normal 140 mEq/L) 301 mOsm/L (normal 290 mOsm/L)

Urine70 mOsm/L Negative

Glucose (fasting) 90 mg/dL (normal 70-100 mg/dL)

4 central nephrogenic diabetes insipidus 2

Diabetes InsipidusCentral diabetes insipidus Nephrogenic diabetes insipidus : (idiopathic)

:mutation V2 receptor gene

hypokalemia,hypercalcimia lithium carbonate, democlocycline

Central diabetes insipidus Nephrogenic diabetes insipidus ADH Posm >>> Hyper-osmolarityUosm>>> Hypo-osmolarity

ADH ADH

Posm >>> Hyper-osmolarityUosm>>> Hypo-osmolarity

dDAVPCentral diabetes insipidus Nephrogenic diabetes insipidus

Urine osmolarity Plasma osmolarity

Urine osmolarity Plasma osmolarity

dDAVPPlasma osmolarity (mOsm/L) Urine osmolarity (mOsm/L)

dDAVP325 70

dDAVP290 500

Central Diabetic insipidus

5 serum ADH central diabetes insipidus nephrogenic diabetes insipidus

Central diabetes insipidus ADH

Nephrogenic diabetes insipidus ADH

Relationship of plasma AVP to urine osmolarity (left) and plasma osmolarity (right) before and during fluid deprivationhypertonic saline infusion test in patients who are normal (blue zones) or have primary polydipsia (blue zones), pituitary diabetes insipidus (green zones), or nephrogenic diabetes insipidus (pink zones).

6 dDAVP urine osmolarity

corticopapillary gradient 1. Countercurrent multiplier system 2. Urea recycle 3. ADH

Countercurrent multiplier systemsolutes

H2O

Single effectDiluting segment

Urea recycle

ADH50-60% in max. urine flow

In the presence of max. ADH level

NO ADH with max. water load

7dDAVP central diabetes insipidus nephrogenic diabetes insipidus

dDAVP (desmopressin) exogenous ADH half-life vasopressor action ADH permeability reabsorb late distal tubule collecting duct

Treatment of nephrogenic diabetes insipidus1. 2. 3. 4. thiazide control the body's fluid levels Li+NaCl reabsorption in thick ascending limb of Henles loop & early distal tubule

ThiazideNa+, K+ Ca2+, Mg2+

Reference .(2548) . 1-2 . . (2552). . Berne and Levy, 6th Edition: Textbook of Medical Physiology Guyton and Hall,11th Edition: Textbook of Medical Physiology Harrisons Principles of INTERNAL MEDICINE, 17th Edition Robins Basis of Pathologic Diseases AMGAD N. MAKARYUS, MD SAMY I. McFARLANE, MD, MPH. Diabetes insipidus: Diagnosis and treatment of a complex disease.PDF file http://emedicine.medscape.com/article/117648-overview[ 22 2553] http://www.nlm.nih.gov/medlineplus/diabetesinsipidus.html[ 23 2553]

Distal tubule Ca 2+ reabsorption

H2O & NaCl reabsorption in late distal tubule & collecting ductaldosterone

aldosterone

Water permeabilityADH