NT receptors Flashcards
Noradrenaline
- α1
- α2
- β1
- β2
- β3
α1-adrenoreceptor
- Type: Gq/11
- Functions:
Pupil dilation
Vasoconstriction
Salivary secretion
Decreased GI motility
Piloerection
Contraction of bladder smooth muscle
Ejaculation
Increased glycogenolysis and gluconeogenesis
α2-adrenoreceptor
- Type: Gi/o
- Functions:
Decreased NT (e.g. NA) release
Platelet aggregation
Inhibition of insulin release
β1-adrenoreceptor
- Type: Gs
- Functions:
Increased force of cardiac contraction
Increased heart rate
β2-adrenoreceptor
- Type: Gs
- Functions:
Bronchodilation
Vasodilation in myocardium/skeletal muscle
Relaxation of uterine smooth muscle
Gluconeogenesis
β3-adrenoreceptor
- Type: Gs
- Functions:
Lipolysis
Thermogenesis
Relaxation of bladder smooth muscle
Acetylcholine
Nicotinic:
- N1
- N2
Muscarinic:
- M1
- M2
- M3
- M4
- M5
M1 ACh receptor
- Type: Gq/11
- Functions:
Mediates synaptic transmission in CNS and PNS.
Can be found in nicotinic synapses. Binding of ACh to these cause a slow depolarisation (EPSP).
Gastric acid secretion
M2 ACh receptor
- Type: Gi/o
- Functions:
Involved in parasympathetic control of the heart and feedback pre-synaptic inhibition in nerve terminals.
M3 ACh receptor
- Type: Gq/11
- Functions:
Sweat secretion
Salivation
Pupil constriction
Ciliary muscle contraction
Vasodilation (via NO)
M4 ACh receptor
- Type: Gq/11
- Functions:
CNS transmission
M5 ACh receptor
- Type: Gq/11
- Functions:
CNS transmission
Histamine
H1-4
Histamine H1 receptor
- Type: Gq/11
- Functions: Inflammatory response
Histamine H2 receptor
- Type: Gs
- Functions: Gastric acid secretion
Histamine H3 receptor
- Type: Gi/o
- Functions: Inhibitory CNS autoreceptor
Histamine H4 receptor
- Type: Gi/o
- Functions: Chemotaxis/cytokine release