-
Adrenergic receptors = GPCRs
1. Types
2. Endogenous ligands
- 1. Types:
- - a1-gq coupled: increases IP3 & Ca --> contracts arterioles
- a2-gi coupled: inhibits AC --> dec cAMP --> inc heart contraction
- b1/b2-gs coupled: activate AC --> inc cAMP --> relax bronchiole SM
- b2 more sensitive to E than to NE (higher affinity for E)
2. Endogenous ligands: E & NE
-
a-adrenergic Rs
1. general fcn
2. types and fcn
1. vasoconstrict arteries to heart, veins, & dec motility of GI SM
2. a1: SM contraction; a2: inhibit insulin release, activate sphinctors, activate thrombocyte agg.
-
b-adrenergic Rs
-types and fcn of each
- b1: inc HR/CO, inc contraction, inc renin secretion
- b2: SM relax, dilation (dec bp), inhibit His release from mast cells
- b3: inc lipolysis in adipose tissue
-
Adrenergic agonists
1. 2 categories
2. Drugs from each category (4 each)
1. Catecholamines, Non-catecholamines
- 2.
- Catecholamines:
- - clonidine (a2 agonist)
- - dobutamine (b1 agonist)
- - isoproterenol (b2 agonist)
- - E & NE (non-selective)
- Non-catecholamines:
- - tetrahydrozoline / visine (a agonist)
- - phenylephrine (a1 agonist)
- - pseudoephedrine (a1 agonist)
- - albuterol (b2 agonist)
-
B antagonists (autonomic) - 2
- 1. propanolol (dec HR, bp)
- 2. labetalol (also a1 antagonist)
-
Neostigmine
- AChE inhibitor
- competitive antagonist
-
Treatments for Parkinson's disease (3)
- bromocriptine
- amantadine
- L-DOPA + carbidopa = Sinemet
-
-
-
ephinephrine/NE (CNS)
- non-selective agonist
- catecholamines
-
-
tetrahydrozoline (CNS)
- visine
- non-catecholamine
- a agonist --> constrict bvs to dec red eye
-
phenylephrine, pseudoephedrine (CNS)
- a1 agonists
- non-catecholamines
- decongestant (vasoconstrictor --> dec perfusion rate)
-
albuterol (CNS)
- b2 agonist
- non-catecholamine
- treatment for asthma
-
bromocriptine
- DA agonist
- parkinson's disease treatment
- longer 1/2 life but less effective than LDOPA
-
amantadine
- inc DA release
- parkinson's disease treatment
-
Sinemet (L-DOPA + carbidopa)
- parkinson's treatment
- allows L-DOPA to cross BBB without being metabolized by AAAD (carbidopa inhibits AAAD enzyme)
|
|