Download Antidiuretic Hormone (ADH)

By Jill Ruiz Carreon
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Arginine vasopressin (AVP)
Argipressin
 “Pressor” effect is secondary significance
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9 amino acids
Produced in hypothalamus
Released from posterior pituitary
(pars nervosa) to the blood
Stimulates water retention in the
kidneys
Less water excreted in urine
Regulates and balances water in
blood
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Released into the brain by
neurons of the
hypothalamo-hypophyseal
tract
Suprachaismatic nuclei (SCN)
◦ Regulation of circadian rhythms
◦ Circadian clock genes –
transcribed into mRNA 
proteins
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Role in species-typical
patterns of social behavior
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Hypotension
Increases vasoconstriction  Arterial BP
Compensatory / Regulatory
However, also seen in patients with heart
failure
◦ Too many AVP receptors / AVP secretion
◦ Sympathetic and renin-angiotensin system
activation in heart failure override hypothalamic
control of AVP release
◦ May contribute to the increase in systemic vascular
resistance as well as in renal retention of fluid
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Minimal pressor effects in humans
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Regulation of extracellular fluid
Conserve body water by reducing urine
output
ADH binds to aquaporins in the plasma
membranes of the collecting duct epithelial
cells
◦ Transports solute-free water through tubular cells
◦ Back into blood
◦ Decreases plasma osmolarity and increases urine
osmolarity
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Work with ADH to maintain water metabolism
By sensors in the hypothalamus reacting to
the ccn of particles in your blood
◦ Na+, K+, Cl-, CO2, etc
◦ Unbalanced /   sensors tell kidneys to store or
release water to maintain a healthy range
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Regulate body’s sense of thirst
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Specialized membrane channel proteins
Made up of single peptide chain consisting of
about 270 aa
Facilitate water transport across cell
membranes
At least 7 expressed in kidneys
◦ AQP 1, 2, 3, 4, 6, 7, 11
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Role in short- & long-term regulation of
water balance and pathophysiology of water
balance disorders
Aquaporin Group Localization in Kidney
AQP 1
APM/BLM of proximal tubules and
descending thin limbs
AQP 2
APM/VES of principal cells of collecting
ducts
AQP 3
BLM of collecting ducts
AQP 4
BLM of medullary collecting ducts
AQP 6
Cortex, Medulla
AQP 11
Proximal tubule (Intracellular)
AQP: Aquaporin, APM: Apical membrane, BLM: Basolateral membrane, VES: Vesicles
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Cloned as an ADH-regulated water channel of
CD
Basal state: AQP2 stored in intracellular
vesicular compartment
With ADH stimulation, it moves quickly to
apical membrane where it acts as water
channel for the ccn of urine
ADH acts at V2 receptors in BLM of CD
principal cells
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Protein-coding gene
Subfamily of G-protein coupled receptors
◦ AVPR1B, V2R and OXT receptors
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Mediates:
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Vasoconstriction
Antidiuresis
ACTH release
Cell contraction and proliferation
Platelet aggregation
Release of coagulation factor
Glycogenolysis
By G proteins that stimulate a
phosphatidylinositol-calcium second messenger
system
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AVPR2 gene provides for production
of this protein
Located on Chromosome Xq28
ADH + V2 Receptor = trigger chemical
reactions for body’s water balance
control
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SIADH
Symptoms:
◦ Headache, Nausea, Vomiting
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Associated with:
◦ Leukemia, lymphoma, lung / pancreatic / bladder /
brain cancers, systemic cancers that produce ADH,
MS, Epilepsy, Acute intermittent porphyria, TB,
dehydration, brain trauma, and surgery
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Nephrogenic diabetes insipidus
◦  very dilute urine
◦ Symptoms: excessive urination (polyuria), extreme
thirst (polydipsia)
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May be due to compulsive water drinking or
low blood serum osmolality
Central diabetes insipidus
◦  in production of ADH by hypothalamus or
realease of ADH from pituitary gland
◦ Symptoms: excessive urination (polyuria), extreme
thirst (polydipsia), often tired since sleep
interrupted by urination urges, clear, odorless and
has low ccn of particles in urine
◦ Lead to severe dehydration
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“Antidiuretic Hormone (ADH) Test”
http://www.healthline.com/health/adh#Purpose3
“Aquaporins: The renal channels”
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2813137/
“AVPR1A arginine vasopressin receptor 1A [Homo sapiens (human)]”
https://www.ncbi.nlm.nih.gov/gene/552
“AVPR1A Gene (Protein Coding)”
https://ghr.nlm.nih.gov/gene/AVPR2#resources
“AVPR2 Gene” https://ghr.nlm.nih.gov/gene/AVPR2#resources
“Definition of Antidiuretic Hormone (ADH)”
http://www.medicinenet.com/script/main/art.asp?articlekey=7000
http://images.slideplayer.com/29/9441578/slides/slide_13.jpg
Human Physiology, McGraw Hill
“Vasopressin” http://www.healthline.com/health/adh#Purpose3
“Vasopressin (Antidiuretic Hormone)”
http://www.cvphysiology.com/Blood%20Pressure/BP016.htm