Table 3.
The effects of the potassium channel blockers 4-AP (KV) and charybdotoxin (BKCa) alone and in the presence of the VOCC blockers nifedipine or mibefradil or the chloride channel blocker niflumic acid on the concentration–response curve to U46619 in endothelium-intact rings
| pEC50 | Rmax % | n | |
|---|---|---|---|
| Control | 7.58 ± 0.07 | 107.5 ± 4 | 5 |
| +4-AP | 8.26 ± 0.47 | 123 ± 2.6 | 5# |
| +4-AP + Nifedipine | 7.35 ± 0.07 | 98.6 ± 3.3 | 5 |
| +4-AP + Mibefradil | 8.33 ± 0.04 | 126 ± 2 | 5# |
| Control | 7.41 ± 0.08 | 107.7 ± 5 | 5 |
| +4-AP + NFA | 7.45 ± 0.1 | 102 ± 6 | 5 |
| +4-AP + DIDS | 7.53 ± 0.04 | 104.5 ± 2.3 | 4 |
| +4-AP + 2-APB | 8.26 ± 0.05 | 120.2 ± 5 | 5# |
| Control | 7.68 ± 0.05 | 104.9 ± 3 | 6 |
| +Charybdotoxin | 8.37 ± 0.06 | 142 ± 3.6 | 6# |
| +Charybdotoxin + Nifedipine | 8.33 ± 0.05 | 145 ± 3 | 5# |
| +Charybdotoxin + Mibefradil | 7.74 ± 0.05 | 105 ± 3 | 6 |
| +Charybdotoxin + NFA | 7.44 ± 0.09 | 109.6 ± 6 | 5 |
| +Charybdotoxin + DIDS | 7.56 ± 0.03 | 102 ± 2 | 6 |
4-AP, 4-aminopyridine; 2-APB, 2-amino ethoxy diphenylborate; DIDS, 4,4′-diisothiocyanostilbene-2,2′-disulphonic acid; NFA, niflumic acid; U46619, 9,11-dideoxy-9α, 11α-methanoepoxy prostaglandin F2α; VOCC, voltage-operated calcium channel.
#Significantly different from control (P < 0.001).