Drugs Acting on the Renal System Flashcards
Renin-angiotensin system functions
Controls sodium excretion and body fluid volume
Regulates blood pressure
Renin
Aspartyl protease made in kidney (responsible for vasopressor response)
Angiotensin
Cofactor to renin that stimulates vasoconstriction
Angiotensin II
Constricts branches of artery
Regulates aldosterone secretion
Stimulates release of vasopressin from hypothalamus
Aldosterone
Controls reabsorption of sodium into the blood stream
Increases sodium levels in plasma
Increases blood volume and vascular resistance
Stimulates production of endothelin (regulates smooth muscle contraction and blood pressure)
Vasopressin
Antidiuretic hormone
Released when dehydrated to conserve water
Kinins
Vasodilators formed by proteolytic enzymes circulating in the plasma
Control Na and K balance and arterial blood pressure
Angiotensin-converting enzyme (ACE)
Nonspecific peptidyldipeptide hydrolase (converts Ang I to Ang II)
Promotes vasoconstriction
ACE inhibitors
Inhibit cleavage of Ang I to Ang II
ACE inhibitor prodrugs
Treat mild-to-moderate hypertension
Most have a 2-(S)-aminophenylbutyric acid ethyl ester moiety
Angiotensin II receptors
AT1, AT2, AT3, AT4
G-protein coupled receptors
AT1: target for managing specific cardiovascular disease (stimulation results in vasoconstriction, etc.)
Main effect of angiotensin antagonists
Block stimulation of AT1 by Ang II
Renin inhibitors
Inhibit cleavage of angiotensinogen to angiotensin I
Used to manage cardiovascular disease
Aldosterone antagonists
Inhibit sodium resorption in distal tubule of nephron, reducing urinary K+ excretion
Results in a weak diuretic effect and decreases cardiac workload