in vitro PHARMACOLOGY 2011 CATALOG - Cerep

26 in vitro pharmacology 2011 catalog
❚ calcitonin gene-related peptide
CGRP - agonist radioligand
binding
Ref. 0373
Q 3 weeks
Included in:
High-throughput profile
Organ safety profile
Source
Ligand
Kd
Non specific
Reference
human recombinant (CHO cells)
[ 125 I]hCGRPa (0.03 nM)
0.06 nM
hCGRPa (1 µM)
hCGRPa (IC 50 : 0.032 nM)
Aiyar, N. et al. (1996) J. Biol. Chem., 271: 11325-11329.
specific binding (% of control)
100
50
0
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log [drug] (M)
hCGRPα
CGRP 8-37
adrenomedullin
human calcitonin
CGRP
cellul ar
Ref. 1621
Ref. 1622
Q 3 weeks
Agonist effect
Antagonist effect
Source
human recombinant (CHO cells)
Measured product cAMP
Detection method HTRF
Agonist effect Control hCGRPa (10 nM)
Reference hCGRPa (EC 50 : 0.11 nM)
Antagonist effect Stimulant hCGRPa (0.3 nM)
Reference hCGRPa (8-37) (IC 50 : 26 nM)
Aiyar, N. et al. (1996) J. Biol. Chem., 271: 11325-11329.
cAMP modulation (% of control)
100
50
0
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log [agonist] (M)
hCGRPα
adrenomedullin
amylin
100
50
0
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log [antagonist] (M)
hCGRPα (8-37)
CGRP
tissue
Ref. 0306
Q 4 weeks
Source
rat vas deferens (field-stimulated)
Agonist hCGRPa (pD 2 = 9)
Antagonist hCGRPa (8-37) (pA 2 = 6.3)
Test concentrations 3 concentrations, n=2 (2 tissues)
for both activities
[Solvent] must be kept ≤ 0.1%
Longmore, J. et al. (1994) Eur. J. Pharmacol., 265: 53-59.
tension (% of control)
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100
-9 -8 -7 -6 -5 -4
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50 -10 -9 -8 -7 -6 -5
-9 -8 -7 -6 -5
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0
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log [agonist] (M)
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hCGRPα (8-37)
none
1 µM
❚ calcium sensing
CaS
cellul ar
Ref. 2144
Ref. 2146
Q 3 weeks
Agonist effect
Antagonist effect
Source
human recombinant (HEK-293 cells)
Measured product intracellular [Ca 2+ ]
Detection method fluorimetry
Agonist effect Control neomycin (100 µM)
Reference neomycin (EC 50 : 11 µM)
Antagonist effect Stimulant neomycin (30 µM)
Reference unavailable
Quinn, S.J. et al. (1997) Am. J. Physiol., 273: 1315-1323.
Ca 2+ mobilization (% of control)
100
50
0
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log [agonist] (M)
neomycin
gadolinium (III) chloride hexahydrate
spermine
CaCl2
[Solvent] must be kept ≤ 0.1%
antagonist effect:
no graph available
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❚ For radioligand binding assays, how should I choose between the agonist and the antagonist models when both are
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available?
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For some binding assays two models are available using either agonist or antagonist as radioligand.
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G-protein-coupled receptors have both high-affinity and low-affinity states that are bound differently by agonists and antagonists. Whereas
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the antagonists bind with an equal affinity to both affinity states, agonists bind poorly to the low affinity state of the receptor. Therefore,
it is advisable to use an antagonist radioligand to evaluate the binding of antagonists knowing that this may fail to reveal the binding
of agonists. On the other hand, an assay using an agonist radioligand is suitable to evaluate both agonists and antagonists.
The testing of a compound in both assays and the comparison of its competition curves against each radioligand may provide information
about its functional activity at the receptor.
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