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外観
白色の粉末
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溶解性
水に溶ける。
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用途
薬理・生理研究試薬。
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使用
Hormone (antidiuretic).
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定義
ChEBI: The predominant form of mammalian vasopressin (antidiuretic hormone). It is a nonapeptide containing an arginine at residue 8 and two disulfide-linked cysteines at residues of 1 and 6.
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適応症
ADH (vasopressin) is released primarily in response to
increases in plasma osmolarity or decreases in blood
volume. It produces its antidiuretic activity in the kidney,
causing the cortical and medullary parts of the collecting
duct to become more permeable to water,
thereby increasing water reabsorption, reducing serum
osmolarity, and increasing its volume. It produces this
effect by binding to a subset of vasopressin receptors called V2 that have relatively high affinity
for the hormone. ADH also has actions at sites other
than the kidney. V2 receptors also mediate an increase
in circulating levels of two proteins involved in blood
coagulation: factor VIII and von Willebrand’s factor.At
higher concentrations, ADH interacts with V1 receptors
to cause a general constriction of most blood vessels. It
also interacts with V3 (or V1b) receptors to increase
ACTH release, although the major control of ACTH release
occurs through corticotropin-releasing hormone.
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一般的な説明
Vasopressin tannate (PitressinTannate) is a water-insoluble tannate of vasopressin administeredintramuscularly (1.5–5.0 pressor units daily)for its prolonged duration of action by the slow release ofvasopressin. It is particularly useful for patients who havediabetes insipidus, but it should never be used intravenously.
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危険性
A poison.
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作用機序
ADH itself is available for injections (Pitressin) but
has a half-life of about 15 minutes. Desmopressin
(DDAVP) is an analogue without an amino group at
the first amino acid and with D-arginine instead of Larginine.
This analogue is more stable and has very little
pressor activity. Desmopressin can be given subcutaneously
or nasally, and the effects last for 12 hours.
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臨床応用
Because it is stable, desmopressin is preferred for
treatments especially if pressor effects are not desired.
The primary indication for therapy is central diabetes
insipidus, a disorder that results when ADH secretion is
reduced and that is characterized by polydipsia,
polyuria, and dehydration. Desmopressin is also used to
reduce primary nocturnal enuresis, or bedwetting, in
children. It is useful in people with mild hemophilia A
or with some types of von Willebrand’s disease, in which
von Willebrand’s factor is present at low levels. In these
cases, desmopressin is given when excessive bleeding
occurs or before surgery to help reduce bleeding indirectly
by increasing the amounts of coagulation factors.
A possible adverse effect of desmopressin is water intoxication
if too much is taken.
ADH antagonists, including nonpeptide analogues
that may be taken orally, have been developed with
specificity for each of the receptor types. In the future,
those that block V1 receptors may be useful in treating
hypertension, and those that block V2 receptors may be
useful in any condition of excessive water retention or
hyponatremia, for which so far there is no satisfactory
therapeutic treatment.
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安全性プロファイル
A poison by intravenous route.When heated to decomposition it emits toxic vapors ofNOx and SOx.
