Receptors (G-protein coupled receptors) Flashcards
(20 cards)
What are the sympathetic receptors?
Alpha 1 and 2 and Beta 1 and 2
What are the Parasympathetic Receptors?
M1, M2, M3
What is the major function of alpha 1
Vascular smooth muscle contraction, Pupillary dilation, Intestinal and bladder sphincter contraction
Dilates veins and eyes, contracts butthole and peehole
Major FUnction of alpha 2
Lowers sympathetic outflow Lowers insulin release Lowers lipolysis enhances platelet agg Lowers
Major function of Beta 1
High heart rate and high contractility
Also Renin release and lipolysis
Major Function of Beta 2
Vasodilation, Bronchodilation, Increased heart rate, increased heart contractility, increased lipolysis, in creased insulin release, increased aqueous humor
decreased uterine tone,
Major Function of Muscarinic 1
enteric nervous system
Major function of M2
Lowers heart rate, contraction of atria
Major function of M3
Increased secretions (tears, stomach, lungs), gut peristalsis, bladder contraction, BRONCHOCONSTRICTION (so cholinomimetics can make asthma worse), pupillary sphincter muscle contraction
D1 receptor function
Relaxes vascular smooth muscle
D2 receptor function
modulates transmitter release
Major function of H1
Nasal and bronchial mucous production, pruritis, pain, bronchiole contraction
Major Function of H2
increase gastric acid secretion
V1 receptor major function
vasopressin so it does vascular smooth muscle contraction…often given in codes to raise bp
Receptrs that fall into the Gq class
Qc’s HAVE 1 M&M
Means Gq receptors are H1, A1, V1, and M1 and M3
Gs receptors do what
stimulate adenylyl cyclase
Gi receptors inhibit,,,,what are the Gi receptors
MAD 2’s….M2, A2, D2
Gq pathway— this is how the receptors mentioned above that fall into this category elicit the effect we just described
Activation of Gq receptor leads to activation of phospholipase C.
- This converts lipids to PIP2 which can then turn into DAG and IP3
- DAG turns into Protein Kinase C
- IP3 leads to increased calcium and smooth muscle contraction
Gs pathway — this is how the receptors mentioned above that fall into this category elicit the effect we just described
Gs activation activates adenylyl cyclase
- Adenylyl cyclase activates ATP which stimulates cAMP to activate Protein Kinase A….leads to increased calcium in the heart and Myosin
Gi inhibits the adenylyl cyclase pathway
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