Debbie Hay- 6 Flashcards
What are examples of ligand gated ion channels causing disease?
Mutations in some GABA receptors may underlie some instances of seizures
These can be targeted by several drugs such as anaesthetics, barbiturates and benzodiazepines
Some venoms can target ion channels such as the alpha-bungarotoxin from the venom of the banded krait snake which binds to nAChR at the neuromuscular junction causing respiratory failure
What are the therapies that target receptor tyrosine kinases?
Insulin therapy
Herceptin which targets the over expression of EGFR in tumour cells, specifically ErbB2d (Her 2) gene in breast cancers, this has 4 related receptors (Her 1,2,3,4) Her 2 has no known ligand and will activate the other receptors effectively acting as EGF
A monoclonal antibody can target Her 2 and reduce block its effects
How can the Ras gene be implicated in cancers?
It is frequently mutated so that it cannot hydrolyse GTP and is trapped in the on position
What is the most common class of receptor targeted by drugs and what are some examples?
GCPRs, including beta-adrenoreceptor agonists for asthma, H2 receptors for ulcers
What is the relevance of GCPR signalling and diabetes?
Byetta is a drug which mimics GLP-1 increasing cAMP activating PKA which phosphorylates kinases important for the exocytosis of insulin containing granules.enhancing glucose mediated insulin secretion
Galpaha(i) agonists must be avoided as they have the opposite effect
Galpha(q) agonists can also be used as they increase intracellular calcium which also aids exocytosis of granules
How is GCPR signalling relevant to cholera?
The A1 subunit of the cholera toxin acts with mono-ADP transferase activity, giving a ADP ribose to Galpha(s) stabilizing this G protein in its active form increase cAMP, forcing CFTR to remain open, causing loss of fluids
