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13 Cards in this Set
- Front
- Back
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Angiotensionogen released in response to what from where?
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Low BP and Na+. From liver. Circulates.
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Angiotensionogen is what?
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alpha2 globulin. Inactive precursor waiting to be activated by renin.
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ACE found where?
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endothelial cells in vasculature and dominant in pulmonary circulation.
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Renin released from where?
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Juxtaglomerular cells lining arterioles
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Rate limiting step of the process?
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Renin release
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Renin secretion influced by what?
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1. [Local] Less blood blow to kidney therefore lower wall pressure in afferent artierioles
2. [Local] Lower tubular Na 3. [CNS] Lower systemic blood pressure (picked up by baroreceptors) -> sympathetic nerves directly innervate JG cells. |
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Aliskiren
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1st renin inhibitor introduced in 2007 to treat high bp.
Very expensive therefore held back unless other BP treatments fail to work. Orally active non peptide inhibitor. Therefore->inhibits rate limiting step |
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Inhibition of renin release?
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Beta adrenoceptor->blocks sympathetic innervation of J.G cells. Not all renin is inhibited
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Captopril + Details
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Inhibits ACE - fits very well into the enzyme and blocks it.
First ACE inhibitor. Most common drug to treat hypertension and heart failure. Non peptide orally active. Very potent ki=2nm Only drug proven to prolong life in heart failure. Side effects: very safe however: enhances bradykinen therefore -->irritant cough. Sulphydryl comound therefore immune hypersensitivity. |
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Enalapril
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Non peptide orally active.
Pro drug-active metabolite = enalaprilic acid more potent (ki=0.2nm) Longer 1/2 life ->plasma esterase activates it over the course of the day. Therefore only a single dose needed. Side effect: Irritant cough |
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What does the AT1 receptor mediate?
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Vasoconstriction
Adrenaline release Prejunctional enhancement of NA Aldosterone production |
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Losartan
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AT1 receptor vompetitive inhibitor
Just as effective as ACE inhibitors however, newer, thereofre more expensive Physicians can only prescribe if patients do not respond well to other drugs or have irritant cough. |
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spironolactone
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Synthetic steroid competitive antagonist at aldosterone receptor in the distal convoluted tubule.
Potassium sparing diuretic Major use in heart failure when there is overactivity of the renin angiotensin system. |
