Lecture 28 - High Blood Pressure Part 2 Flashcards
how do calcium channel blockers (CCBs) work?
inhibiting the movement of Ca++ by binding to L-type voltage gated Ca++ channel receptors
true or false: calcium channel blockers (CCBs) are generally recommended as a first line therapy and in combination therapies for high blood pressure
true
what is the main signal for smooth muscle contraction
increased intracellular Ca++
a class of calcium channel blockers (CCBs) that act by vasodilating the peripheral vasculature
dihydropyridine
what are two examples of dihydropyridines?
amlodipine and clevidipine
a class of calcium channel blockers (CCBs) that act on Ca++ channels of cardiac and smooth muscle to decrease muscle contractility
non-dihydropyridines
what are two examples of dihydropyridines?
verapamil and diltiazem
the renin-angiotensin-aldosterone system (RAAS) is targeted by several classes of drugs, with two primary classes being:
- angiotensin receptors blockers (ARBs)
- angiotensin converting enzyme inhibitors (ACEis)
an enzyme secreted by the kidneys at the juxtaglomerular apparatus that processes angiotensinogen to angiotensin I (ATI)
renin
an angiotensin converting enzyme that processes angiotensin I (ATI) to angiotensin II (ATII)
ACE
a powerful vasoactive peptide that causes vascular smooth muscle control and aldosterone release
angiotensin II (ATII)
a steroid hormone that promotes reabsorption of Na+ and H2O in the kidney (preserves blood volume and increases blood pressure)
aldosterone
renin release is stimulated by:
the sympathetic nervous system via beta-1 adrenergic receptors
how does inhibition of -beta-1 adrenergic receptors by beta-blockers affect renin?
inhibits renin release
angiotensin converting enzyme (ACE) exists primarily as a membrane bound glycoprotein in the:
pulmonary capillary endothelium
angiotensin (ATII) effects are primarily mediated by the:
ATII receptor (type 1) –> usually called the AT1 receptor
the AT1 receptor activates a _____ pathway to produces second messengers, such as _____, which mobilizes the _____ and activates ______ and different downstream signalling pathways
Gq protein and phospholipase C (PLC), inositol triphosphate (IP3) and diacylglycerol (DAG), intracellular Ca++ store, protein kinase C (PKC)
what effect does mobilizing intracellular Ca++ stores due to AT1 activation have?
leads to activation of calmodulin (CaM) which leads to smooth muscle contraction
what effect does activating protein kinase C (PKC) due to AT1 activation have?
PKC and calmodulin signals trigger the synthesis/release of aldosterone
why is aldosterone not stored in vesicles like neurotransmitters?
because it is lipid soluble
the key targets of aldosterone are found in the _____, including the _____
nephron, distal convoluted tubule
what are the two key targets of aldosterone?
- Na+/K+ ATPase pump
- epithelial Na+ channel (ENaC)
what is the main effect of aldosterone?
promotes Na+ (and therefore H2O) reabsorption
what are two common examples of angiotensin converting enzyme inhibitors (ACEis)?
captopril and enalapril
