0. Receptors Flashcards
Autonomic G-Protein Linked Receptors
Sympathetics
- alpha-1 - Gq protein
- alpha-2 - Gi protein
- beta-1 - Gs
- beta-2 - Gs
Parasympathetics
- M1 - Gq protein
- M2 - Gi
- M3 - Gq
Dopamine
- D1 - Gs
- D2 - Gi
Histamine
- H1 - Gq
- H2 - Gs
Vasopressin
- V1 - Gq
- V2 - Gs
“Qiss (kiss) and qik (kick) till you’re siq (sick) of sqs (sex)”
Alpha-1 Adrenergic Receptor
Gq linked
- Increase IP3 –> Increase Intracellular Ca
- Increase DAG –> Activate protein kinase C
Actions:
- Contract vascular smooth muscle
- Contract pupillary dilator muscle - mydriasis
- Contract intestinal and bladder sphincters
Alpha-2 adrenergic receptor
Gi linked
- Inhibit adenylyl cyclase –> Decrease cAMP –> prevent protein kinase A activation
Actions:
- Decrease sympathetic outflow
- Decrease insulin release
Beta-1 adrenergic receptor
Gs linked
- Activate adenylyl cyclase –> Increase cAMP –> Activate protein kinase A
Actions:
- Increase HR
- Increase contractility
- Increase Renin release
- Increase lipolysis
Beta-2 adrenergic receptor
Gs linked
- Activate adenylyl cyclase –> Increase cAMP –> Activate protein kinase A
Actions:
- Vasodilation
- Bronchodilation
- Increase HR
- Increase contractility
- Increase lipolysis
- Increase insulin release
- Decrease uterine tone
M1 muscarinic receptor
Gq linked
- Increase IP3 –> Increase Intracellular Ca
- Increase DAG –> Activate protein kinase C
Actions:
- CNS and enteric nervous system signalling
M2 muscarinic receptor
Gi linked
- Inhibit adenylyl cyclase –> Decrease cAMP –> prevent protein kinase A activation
Actions:
- Decrease HR of atria
- Decrease contractility of atria
M3 muscarinic receptor
Gq linked
- Increase IP3 –> Increase Intracellular Ca
- Increase DAG –> Activate protein kinase C
Actions:
- Increase exocrine gland secretions (sweat, gastric acid)
- Increase gut peristalsis
- Increase bladder contraction
- Bronchoconstriction
- Pupillary sphincter muscle contraction - Miosis
- Ciliary muscle contraction - accommodation
D1 dopamine receptor
Gs linked
- Activate adenylyl cyclase –> Increase cAMP –> Activate protein kinase A
Actions:
- Relax renal vascular smooth muscle
D2 dopamine receptor
Gi linked
- Inhibit adenylyl cyclase –> Decrease cAMP –> prevent protein kinase A activation
Actions:
- Modulate transmitter release, especially in the brain
H1 histamine receptor
Gq linked
- Increase IP3 –> Increase Intracellular Ca
- Increase DAG –> Activate protein kinase C
Actions:
- Increase nasal and bronchial mucus production
- Contract bronchioles
- Pruritus
- Pain
H2 histamine receptor
Gs linked
- Activate adenylyl cyclase –> Increase cAMP –> Activate protein kinase A
Actions:
- Gastric acid secretion
V1 vasopressin receptor
Gq linked
- Increase IP3 –> Increase Intracellular Ca
- Increase DAG –> Activate protein kinase C
Actions:
- Contract vascular smooth muscle
V2 vasopressin receptor
Gs linked
- Activate adenylyl cyclase –> Increase cAMP –> Activate protein kinase A
Actions:
- Increase H2O permeability and reabsorption in the collecting tubules of the kidney
“V2 in the 2 Kidneys”
Receptor coupled Gq protein
Linked to H1, a-1, V-1, M-1, M-3 receptors
- Activates Phospholipase C –> Make PIP –> PIP becomes DAG and IP3 –> DAG activates protein kinase C, and IP3 increase intracellular Ca
“HAVe 1 M&M”