24 Questions
Which of the following is a selective COX-2 inhibitor?
Celecoxib
What is the role of acetyl transferase in the synthesis of PAF?
Acetylates lysoPAF to form PAF
What is the effect of PAF on platelets?
Increases platelet aggregation
What is the source of renin in the renin-angiotensin system?
Kidney
What is the function of angiotensin-converting enzyme (ACE) in the renin-angiotensin system?
Converts angiotensin I to angiotensin II
What is the effect of angiotensin II on blood pressure?
Increases blood pressure
Which of the following is NOT a pharmacological action of PAF?
Inhibits the release of eicosanoids
What is the effect of PAF on renal flow?
Decreases renal flow
What is the function of angiotensin-converting enzyme (ACE) in the renin-angiotensin system?
To convert angiotensin I to angiotensin II
Which of the following enzymes can independently catalyze the conversion of angiotensinogen to angiotensin I?
Cathepsin D
What is the effect of angiotensin II on blood pressure?
It increases blood pressure
What is the primary function of bradykinin?
To regulate blood pressure by vasodilation
Which of the following medications blocks the angiotensin II receptor 1 (AT1R1)?
Losartan
What is the precursor to angiotensin I in the renin-angiotensin system?
Angiotensinogen
What is the effect of angiotensin II on the kidneys?
It increases sodium reabsorption in kidney tubules
What is the role of kallikrein in the synthesis of bradykinin?
It converts prekallikrein to kallikrein
Which of the following peptides is a potent vasoconstrictor?
Endothelin
What is the effect of ETA receptors on blood pressure?
Prolonged increase in blood pressure
Which of the following is a nonselective endothelin receptor antagonist?
Bosentan
Which of the following kinins is a nonapeptide?
Bradykinin
Which of the following receptors mediates vasodilatation?
B2
Which of the following cytokines participates in the pathogenesis of rheumatoid arthritis?
IL-1
Which of the following vasodilators acts together with ACh?
VIP
What is the indication for blockers of ET-1 receptors?
Pulmonary arterial hypertension
Study Notes
COX Inhibitors
- Nonselective COX inhibitors: aspirin-like, inhibit both COX-1 and COX-2
- Selective COX-2 inhibitors: coxibs, preferential COX-2 inhibitors
- Antipyretic and analgesic effects
Platelet Activating Factor (PAF)
- Released from membrane phospholipids by phospholipase A2
- Synthesized by platelets, monocytes, mast cells, eosinophils, renal medullary cells, and endothelium
- Pharmacological actions:
- Increases platelet aggregation
- Potent vasodilator, decreases blood pressure
- Constricts pulmonary vessels
- Increases microvascular permeability
- Releases eicosanoids, generates superoxides
- Contracts nonvascular smooth muscles, increases respiratory secretions, and forms pulmonary edema
- Decreases renal flow
Biogenic Peptides
Angiotensin
- Synthesis: angiotensinogen → angiotensin I → angiotensin II
- Angiotensin II effects:
- Vasoconstriction
- Increases peripheral vascular resistance
- Increases blood pressure
- Directly stimulates heart
- Facilitates epinephrine and aldosterone release
- Increases Na reabsorption in kidney tubules
- Releases ADH (vasopressin) to restore blood volume
- Inhibitors: losartan and valsartan (block angiotensin receptors), captopril and enalapril (inhibit ACE)
Bradykinin
- Member of the kinin group
- Actions:
- Mediates nociception (pain)
- Regulates blood pressure (vasodilator)
- Increases capillary permeability
- Balances electrolytes and fluid
- Contracts gut slowly and stimulates prostaglandin synthesis
- Produced by tissue damage, viral infection, allergic reaction, and inflammation
- Synthesis: prekallikrein → kallikrein → kininogen → bradykinin
- Receptors:
- B1: mediates vasoconstriction
- B2: mediates vasodilation, permeability, smooth muscle contraction, and pain
- B3: mediates guinea pig tracheal contraction
Endothelin
- Potent vasoconstrictor peptides isolated from aortic endothelial cells
- Receptors:
- ETA: causes prolonged increases in blood pressure
- ETB: causes transient drop in blood pressure
- Endothelin receptor antagonists: bosentan (nonselective), ambriSentan, macitentan (indicated for PAH treatment)
Vasodilators and Neuropeptides
- Vasodilators:
- NPY (with NA)
- ANP
- VIP (with ACh)
- CGRP
- Kinins (kallikrein, bradykinin)
- SP
- Neuropeptides:
- CCK: involved in pathogenesis of panic reactions
Cytokines
- Soluble proteins and glycoproteins that interact with specific cellular receptors
- Involved in inflammatory and immune response
- Cytokines act together on: endothelium, leucocytes, mastocytes, fibroblasts, stem cells, and osteoclasts
- Examples:
- Interleukins (ILs)
- IL-1: participates in the pathogenesis of rheumatoid arthritis
- IL-2: used in renal carcinoma but has ADRs
- IL-11: stimulates thrombocytopoiesis
This quiz covers the different types of COX inhibitors, including non-selective and selective inhibitors, as well as their effects on the body. Learn about aspirin-like NSAIDs and their role in pain relief and inflammation reduction.
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