Pharmacological profile of cabergoline and its derivatives at 5-HT2BRs in porcine pulmonary arteries
Data are means ± S.E.M. from n animals given in parentheses. Emax is expressed as a percentage of the maximal relaxation induced by the agonist and bradykinin (0.01 μM) finally added at the end of each experiment.
| Compound | pEC50 | Emax | pKP | pA2 |
|---|---|---|---|---|
| % | ||||
| Agonist | ||||
| 5-HT | 8.52 ± 0.05 (26)a | 73 ± 2a | 6.59 ± 0.07b,c | |
| Cabergoline | 8.15 ± 0.07 (5) | 58 ± 6d | 6.45 ± 0.06 (4)c | |
| 6-Cyclopropylmethylcabergoline | 8.10 ± 0.14 (6) | 75 ± 6e | 6.63 ± 0.25 (4)c | |
| 6-Propylcabergoline | 7.87 ± 0.03 (5) | 86 ± 3f | 6.43 ± 0.09 (4)c | |
| 6-Ethylcabergoline | 8.08 ± 0.09 (4) | 68 ± 1g | 6.34 ± 0.20 (4)c | |
| 6-Norcabergoline | 22 ± 6h | 7.28 ± 0.12 (4)i | ||
| Antagonist | ||||
| 6-Methylcabergoline | 0 | 10.06 ± 0.12 (4)j |
↵a Pooled data obtained from all experiments.
↵b Data from Glusa and Pertz (2000).
↵c Apparent pA2 for SB204741 at 3 μM.
↵d Not significantly different from respective 5-HT control curve (64 ± 5).
↵e Not significantly different from respective 5-HT control curve (74 ± 5).
↵f Significantly different from respective 5-HT control curve (75 ± 4).
↵g Not significantly different from respective 5-HT control curve (72 ± 2).
↵h Significantly different from respective 5-HT control curve (76 ± 8).
↵i Calculated from the antagonism of the 5-HT response by the partial agonist at a concentration of 0.2 μM (Marano and Kaumann, 1976).
↵j Apparent pA2 tested at 1.5 nM.