G protein linked 2nd messengers Flashcards
Alpha 1
G protein class: Q
- Increase vascular smooth muscle contraction
- Increase pupillary dilator muscle contraction (mydriasis)
- Increase intestinal and bladder sphincter muscle contraction
Alpha 2
G protein class: i
- decrease sympathetic outflow
- decrease insulin release
- decrease lipolysis
- increase platelet aggregation
- decrease aqueous humor production
Beta 1
G protein class : S
Increase heart rate (tachycardia)
Increase contractility
Increase renin release
Increase lipolysis
M1
(parasympathetic)
G protein class: Q
CNS, enteric nervous system
M2
(parasympathetic)
G protein class: i
decrease heart rate and contractility of atria
M3
(parasympathetic)
G protein class: Q
Increase exocrine gland secretions
lacrimal, saliva, gastric acid
Increase gut peristalsis
Increase bladder contraction
Bronchoconstriction
Increase pupillary sphincter muscle contractions (miosis)
Ciliary muscle contraction (accommodation)
D1
G class protein: S
Relaxes renal vascular smooth muscle (low dose)
D2
G class protein: i
Modulates transmitter release, especially in brain
H1
G class protein: q
increase nasal and bronchial mucus production
increase vascular permeability contraction of bronchioles
puritus
pain
H2
G class protein: s
increase gastric acid secretion
V1
G class protein: q
Increase vascular smooth muscle contraction
V2
G class protein: s
Increase H2O permeability and
reabsorption in collecting tubules of kidney
receptor —-> Gq
- –> phosphlipase C —> (PIP2—>) DAG –> Protein Kinase C
- –> IP3 = increase Ca2+ — smooth muscle contraction
HAVe 1 M&M
Receptor —Gs
–> cAMP –> Protein kinase A – increase ca2+ heart and inhibits myosin light chain kinase (smooth muscle)
MAD 2’s are the inhibitors of this pathway
