Ca++ elevations induced by different alpha-2 adrenoceptor agonists in the recombinant cell lines expressingalpha-2 adrenoceptors
| Alpha-2A | Alpha-2B | Alpha-2C | ||||
|---|---|---|---|---|---|---|
| Δ[Ca++]max (% of NA) | EC50(nM) | Δ[Ca++]max (% of NA) | EC50(nM) | Δ[Ca++]max (% of NA) | EC50(nM) | |
| Noradrenaline | 100 ± 5.2 | 83.4 ± 26 | 100 ± 3.4 | 68.9 ± 15.3 | 100 ± 5.0 | 50.2 ± 15.3 |
| UK14,304 | 104.5 ± 4.4 | 23.7 ± 6.1 | 43.7 ± 3.8 | 367 ± 152 | 125.9 ± 6.4 | 303 ± 77 |
| d-Medetomidine | 59.4 ± 2.8 | 2.78 ± 1.05 | 88.5 ± 4.9 | 5.36 ± 2.20 | 93.8 ± 4.2 | 4.56 ± 1.20 |
| Oxymetazoline | 30.5 ± 2.1 | 5.85 ± 2.97 | 120.4 ± 5.9 | 252 ± 62 | 55.5 ± 2.6 | 67.8 ± 16.1 |
| Clonidine | 39.9 ± 2.5 | 26.6 ± 10.8 | 16.3 ± 1.4 | 395 ± 194 | 65.0 ± 5.9 | 517 ± 213 |
The result are pooled from all the experiments with α2-expressing CHO cells and they are presented as mean ± S.E.M. of values obtained by curve-fitting and normalized to the noradrenaline response (NA). Number of batches of cells for each ligand is three to four (determinations performed at least in triplicate).