Anti-inflammatory drugs (Concepts) Flashcards
What is the process of bradykinin synthesis?

What are the 2 types of kininogens and what are their derivatives?
- High molecular weight (HMW) kininogen → Bradykinin
- Low molecular weight (LMW) kininogen → Kallidin
How is Hageman factor/factor VII activated?
Contact with -ve surface when leaking out of blood vessels (e.g. collagen, basement membrane)
What is the main functions of plasma/tissue kallikreins?
- Plasma kallikreins: Bradykinin production
- Tissue kallikreins: Kallidin production
How is bradykinin inactivated?
Cleavage by kininses
What are the kininases and their mechanisms of action?
- Kininase I: Removes C-terminus Arg to form des-Arg-Bradykinin, a ligand for bradykinin B1 receptors.
- Kininase II: Removes 2 C-terminus amino acids to inactivate badykinin.
What is another name for kininase II?
Angiotensin converting enzyme (ACE)
What are the bradykinin receptors?
- B1 (Gq-coupled)
- B2 (Gq-coupled)
When are B1 receptors expressed and what are its ligands?
- Expression: Induction by pro-inflammatory cytokines such as IL-1
- Ligand: des-Arg-Bradkinin
When are B2 receptors expressed and what are its ligands?
- Expression: Constitiutive
- Ligands:
1. Bradykinin
2. Kallidin
What are the effects of bradykinin receptor stimulation?
- Vasodilation
- Pain
How do bradykinin receptors mediate vasodilation?
- B1 →(endothelium)→ ↑[Ca2+]i → eNOS → ↑[NO] →(VSM)→ ↑[cGMP] → PKG → Vasodilation
- B2 →(endothelium)→ ↑[Ca2+]i → PLA2 → ↑[PGI2] →(VSM)→ ↑[cAMP] → PKA → Vasodilation
How do bradykinin receptors mediate pain?
- Bradykinin receptors on nociceptors (Aδ/C neurones) cause stimulation and pain
- Bradykinin receptors on nociceptors also cause sensitisation to pain through phosphorylation of ion channels and decreasing threshold of stimulation
How is kallikrein inhibited?
C1-esterase inhibitor
What are the causes of hereditary angioedema (HAE)?
- Type I HAE: Mutations compromising C1-inhibitor synthesis/secretion
- Type II HAE: Mutations causing production of inactive C1-inhibitor
What are the 4 groups of cytokines?
- Interleukins
- Chemokines
- Interferons
- Colony-stimulating factors
What is the nomenclature of chemokines?
- C = 1 N-terminus Cys residue
- CC = 2 adjacent N-terminus Cys residue
- CXC = 2 N-terminus Cys residue separated by an amino acid
- CX3X = 2 N-terminus Cys residues separated by 3 amino acids
What is unusual about chemokine receptors compared to other cytokine receptors?
Chemokine receptors are GPCRs while most cytokine receptors are RTKs
What are the functions of interleukins?
- Pro-inflammatory effects
- Anti-inflammatory effects
What are the function of chemokines?
Chemoattraction (mainly), but not restricted to.
What are the functions of interferons?
- INFα & INFβ: Anti-viral function
- INFγ: Stimulation of TH1 response
What are the functions of colony-stimulating factors?
Stimulates formation of mature colonies of leukocytes
What cell are NGF secreted from on what is its function?
- Mast cells and macrophages
- Sensitisation of nociceptors
What receptors mediate pain sesnitisation effects of NGF?
Tropomyosin-related kinase A (TrkA)