11.20.17 Vasopressin & Oxytocin Flashcards
Vasopressin
Targets (3):
Principal action (3):
Vasopressin
Targets (3): kidney, blood vessel, anterior pituitary
Principal action (3): Water retention, vasoconstriction, ACTH release
Oxytocin
Targets (2):
Principal action (2):
Oxytocin
Targets (2): Uterus, mammary
Principal action (2): Contraction of smooth muscle, alveoli
Vasopressin (ADH) main function is to conserve water by reducing ______ output, regulate kidney ______ production and trafficking.
Vasopressin (ADH) main function is to conserve water by reducing urine output, regulate kidney aquaporin production and trafficking.
V1 receptors -G protein-coupled, \_\_\_\_\_ receptor system Describe its effect on: -vascular smooth muscle -liver \_\_\_\_\_\_\_\_\_\_\_ -\_\_\_\_\_\_\_ release -\_\_\_\_\_\_\_ synthesis
V1 receptors -G protein-coupled, phosphatidyl inositol (IP3) receptor system Describe its effect on: -vascular smooth muscle -liver glycongenolysis -ACTH release -Prostaglandin synthesis
V2 receptors:
- G protein-coupled _____ receptor system
- Increases water resorption in the kidney by increasing water permeability of ______ channels in renal luminal membranes
V2 receptors:
- G protein-coupled adenylyl cyclase (cAMP) receptor system
- Increases water resorption in the kidney by increasing water permeability of aquaporin-2 channels in renal luminal membranes
Vasopressin binds receptors in ____ or ____ of the kidney. It promotes the reabsorption of water. The tubules are impermeable to _____ without vasopressin.
Vasopressin binds receptors in distal or collecting duct of the kidney. It promotes the reabsorption of water. The tubules are impermeable to water without vasopressin.
Vasopressin stimulates insertion of “water channels” or _______ into the membranes of kidney tubules. Insertion results in transport of solute-free water through tubular cells and into blood:
- _______ in plasma osmolarity
- _______ in urine osmolarity
Vasopressin stimulates insertion of “water channels” or aquaporins into the membranes of kidney tubules. Insertion results in transport of solute-free water through tubular cells and into blood:
- decrease in plasma osmolarity
- increase in urine osmolarity
Kidneys express aquaporin __ and __.
Kidneys express aquaporin 2 and 3.
Aquaporin-3: resides constitutively on the ________, allows water to flow out of the cell after entering _____ channels
Aquaporin-3: resides constitutively on the basolateral membrane, allows water to flow out of the cell after entering aquaporin-2 channels
Aquaporin-2: regulated by V2R stimulated cAMP, is a target for cAMP mediated ____ phosphorylation. Vesicles containing aquaporin-2 fuse to _____ when the cell is stimulated by vasopressin.
Aquaporin-2: regulated by V2R stimulated cAMP, is a target for cAMP mediated PKA phosphorylation. Vesicles containing aquaporin-2 fuse to apical membrane when the cell is stimulated by vasopressin.
_____ takes up water from lumen, ____ facilitates its movement into the blood.
AQP2 takes up water from lumen, AQP3 facilitates its movement into the blood.
Vasopressin causes _____ in blood pressure by contraction of small arteries, in healthy individuals this effect is _____.
Vasopressin causes an increase in blood pressure by contraction of small arteries, in healthy individuals this effect is minimal.
Vasopressin receptors are widely dispersed in _____ regions. It cannot cross the ____. It can promote _____ in rodents and has been implicated in _____ formation.
Vasopressin receptors are widely dispersed in brain regions. It cannot cross the BBB. It can promote social recognition in rodents and has been implicated in memory formation.
V1R antagonists may have ___ and ____ actions.
V1R antagonists may have anti-anxiety and anti-depressant actions.
Hypothalmic osmoreceptors detect plasma ____.
- Dehydration results in _____ secretion
- Overhydration results in _____ secretion
Hypothalmic osmoreceptors detect plasma osmolarity.
- Dehydration results in increased secretion
- Overhydration results in decreased secretion
Other factors that increase secretion of ADH are decreases in _____ and ____, sensed by stretch receptors in heart and large arteries. Not as
Other factors that increase secretion of ADH are decreases in BP and volume, sensed by stretch receptors in heart and large arteries.
Decreases in blood pressure and volume are (more/less) sensitive as increases in osmolarity. Loss of 15-20% of blood volume results however in massive secretion of vasopressin.
Decreases in blood pressure and volume are (less) sensitive as increases in osmolarity. Loss of 15-20% of blood volume results however in massive secretion of vasopressin.
Another stimulus of vasopressin is ____ and ____ which are controlled by regions in the brain with links to the hypothalamus.
Another stimulus of vasopressin is nausea and vomiting which are controlled by regions in the brain with links to the hypothalamus.
Vasopressin dysregulation results in two forms of diabetes insipidus, describe:
- Neurogenic diabetes insipidus: deficiency in secretion of vasopressin, causes varied (head trauma, infections/tumors of hypothalamus, genetic mutations to the vasopressin gene)
- Nephrogenic diabetes insipidus: kidney unable to respond to vasopressin, common cause is renal disease, less common is mutations in the vasopressin receptor gene or AQP2 gene
A major symptom of diabetes insipidus is _______, diagnosis and treatment must differentiate from polydipsia. Rarely life-threatening if adequate water is available.
A major symptom of diabetes insipidus is excessive urine, diagnosis and treatment must differentiate from polydipsia. Rarely life-threatening if adequate water is available.
Syndrome of inappropriate antidiuretic hormone (SIADH) is characterized by _____. It can lead to ___ and ___. Causes may include CNS injuries/malignancies, psychotropic drugs (haloperidol, TCA, vinca alkaloids, sulfonylureas).
Syndrome of inappropriate antidiuretic hormone (SIADH) is characterized by excessive release of vasopressin. It can lead to hyponatremia and hypoosmolality. Causes may include CNS injuries/malignancies, psychotropic drugs (haloperidol, TCA, vinca alkaloids, sulfonylureas).
Vasopressin treats (4):
- neurogenic diabetes insipidus
- acute bleeding d/t esophageal varices or colonic diverticula
- CPR, as first line alternative to epinephrine, also in v-fib with epinephrine.
- vasodilatory shock
Desmopressin is degraded (faster/slower) than vasopressin, and has ___ effect on BP.
Desmopressin is degraded (slower) than vasopressin, and has little effect on BP.
Desmopressin treats (4):
- neurogenic diabetes insipidus
- nocturnal enuresis
- hemophilia A (VIII deficiency)
- von Willebrand syndrome (I and IIa only)
