Pharmacology 7

Receptors

A
- Ionotrophic: ligand gated chloride ion channel
- 2 alpha, 1 beta, 1 delta, 1 gamma
  - (like foetal nicotinic receptors)
  - GAMMA FOR GABA!!
- when GABA binds, Cl channels open, hyper polarising the membrane
- benzodiazepines increase receptor affinity for GABA
- types
  - GABAa BZ1
    - spinal cord & cerebellum
    - anxiolysis
  - GABAa BZ2
    - spinal cord, hippocampus and cerebral cortex
    - sedation and anti-convulsant
B
- Metabotrophic: GPCR
- when activated, increases K conductance, hyper polarising the membrane
- baclofen activates GABA B

NMDA
- activated by 2 glutamate and 2 glycine
- sustained C-fibre stimulation releases glutamate, which along with glycine (co-agonist) activates receptor, leading to increased intracellular Ca and positive feedback response to glutamate —> hyperexcitable state, causing pain
- antagonised by ketamine and nitrous

Insulin binding stimulates the phosphorylation of tyrosine, which increases intracellular tyrosine kinase activity