VPAC1 | VPAC2 | N-VPAC2/VPAC1 | N-VPAC1/VPAC2 | N → EC1 VPAC1/VPAC2 | ||||||
---|---|---|---|---|---|---|---|---|---|---|
IC50 | EC50 | IC50 | EC50 | IC50 | EC50 | IC50 | EC50 | IC50 | EC50 | |
nM | ||||||||||
VIP | 0.5 ± 0.11-a | 0.5 ± 0.11-a | 3.0 ± 0.21-b | 15 ± 2.51-b | 0.5 ± 0.1 | 0.5 ± 0.1 | 100 ± 201-a 1-b | 50.0 ± 121-a 1-b | 80 ± 22 | 100 ± 25 |
Ro 25-1553 | 800 ± 2001-a | 1000 ± 2501-a | 1.5 ± 0.41-b | 5.0 ± 1.21-b | 5.0 ± 1.01-b | 3.0 ± 0.81-b | 3000 ± 8001-a | 1000 ± 2001-a | 200 ± 50 | 1000 ± 2001-a |
Ac His1 VIP | 3.0 ± 0.7 | 10.0 ± 2.2 | 1.5 ± 0.3 | 5.0 ± 0.1 | 3.0 ± 0.1 | 8.0 ± 0.3 | 100 ± 151-a 1-b | 30.0 ± 81-a | 80 ± 10 | 100 ± 25 |
C6-VIP | 2.0 ± 0.31-c | 3.0 ± 0.71-a 1-c | 1.0 ± 0.11-c | 0.3 ± 0.11-b 1-c | 5.0 ± 1.21-a 1-c | 10.0 ± 1.51-a 1-c | 3.0 ± 0.81-c | 1.0 ± 0.21-c | 5.0 ± 1.01-c | 5.0 ± 0.91-c |
VIP(5-28) | 2000 ± 220 | 300 ± 901-b | 3000 ± 8001-a | 30 ± 121-b | 100 ± 251-b 1-d | 20 ± 71-b | 100 ± 151-b 1-d | |||
VPAC1 antagonist | 2.0 ± 0.31-a | 2.0 ± 0.31-c | 2000 ± 300 | 1000 ± 2001-b | 8.0 ± 3.01-a | 15.0 ± 41-a 1-d | 3.0 ± 0.8 | 5.0 ± 1.1 |
The values (±S.D.) were the mean of at least three determination.
↵1-a Values significantly different from the corresponding VPAC2 values.
↵1-b Values significantly different from the corresponding VPAC1 values.
↵1-c C6-VIP EC50 and IC50 values significantly different from the corresponding VIP values.
↵1-d These values corresponded to the K ivalues of inhibition of VIP-stimulated adenylate cyclase activity.