Sponsored Links
Results 1 to 3 of 3
  1. #1
    Roxanita is offline Senior Member
    Join Date
    May 2004
    Posts
    539
    Downloads
    0
    Uploads
    0
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Physiology N* Q-12

    Advertisements



    Which of the following tests best distinguishes central diabetes insipidus from nephrogenic diabetes insipidus?

    A) Injection of ADH (vasopressin)

    B) Injection of hypertonic saline

    C) Injection of insulin

    D) Water deprivation

    E) Water loading

  2. #2
    mjl1717's Avatar
    mjl1717 is offline Member
    Join Date
    May 2003
    Posts
    176
    Downloads
    8
    Uploads
    0
    Thanks
    0
    Thanked 0 Times in 0 Posts

    ADH

    injection of vasopressin

  3. #3
    Roxanita is offline Senior Member
    Join Date
    May 2004
    Posts
    539
    Downloads
    0
    Uploads
    0
    Thanks
    0
    Thanked 0 Times in 0 Posts

    a) ADH (Vasopressin)

    Nephrogenic Diabetes Insipidus and Central Diabetes Insipidus have similar clinical presentation: polyuria, polydipsia, electrolyte imbalance, dehydration, urinalysis shows low specific gravity...
    In Central DI an Injection of ADH (vasopressin) will temporaly fix the problem while in Nephrogenic DI will not have any effect because on this condition there is a lack of receptor for ADH (water channels or aquaporins)




    http://www.mfi.ku.dk/ppaulev/chapter25/Chapter%2025.htm


    CHECK THIS...

    Nephrogenic Diabetes Insipidus

    Congenital Nephrogenic Diabetes Insipidus
    Babies with NDI present with vomiting, constipation, failure to thrive, fever, and polyuria. Symptoms usually occur during the first week of life, and on testing the patients are found to have HYPERNATREMIA and a low urine osmolality. Historically, the patients were reported to have mental retardation, complications of urinary tract dilatation, and intracranial calcification. An association between intracranial calcification and mental retardation has not been established, and the calcification may be a consequence of hypernatremia rather than of congenital disease.

    DIAGNOSIS:The diagnosis is established by high levels of VASOPRESSIN in the plasma in the presence of hypotonic polyuria and, subsequently, by the absence of a response to administered desmopressin. There are two causes:
    (1) mutation in the V2 receptor and
    (2) mutations in the aquaporin-2 water channels



    DIFERENT MUTATIONS (SEX-RELATED)

    *** More than 90% of cases of congenital nephrogenic diabetes insipidus are X-linked disorders occurring in males and are caused by one of more than 132 different V2 RECEPTOR MUTATIONS.

    *** When the proband is a girl, it is likely that the defect is an AQUAPORIN-2 WATER CHANNEL MUTATIONgene on chromosome 12,q1213 producing an autosomal recessive disease.


    ACQUIRED NEPHROGENIC DIABETES INSIPIDUS, here the kidney lacks of capacity to produce a concentrated urine; this may be caused by numerous chronic renal diseases that distort the architecture of the kidney (e.g., polycystic kidney disease; renal infarcts with neovascularization, such as produced by sickle cell anemia; and infiltrative disease of the kidney).

Similar Threads

  1. Physiology I
    By jasonb123 in forum American University of the Caribbean (AUC)
    Replies: 44
    Last Post: 01-07-2009, 08:09 PM
  2. Physiology N* Q-18
    By Roxanita in forum USMLE Step 1 Forum
    Replies: 3
    Last Post: 11-17-2004, 08:58 AM
  3. Physiology N* Q-20
    By Roxanita in forum USMLE Step 1 Forum
    Replies: 2
    Last Post: 10-05-2004, 12:24 PM
  4. Physiology N* Q-19
    By Roxanita in forum USMLE Step 1 Forum
    Replies: 2
    Last Post: 10-05-2004, 10:20 AM
  5. Physiology
    By Anonymous in forum USMLE Step 1 Forum
    Replies: 2
    Last Post: 10-02-2004, 08:34 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •