Table 2.
Effects of desensitising treatments on cAMP-elevating compounds
| % Inhibition | |||||
|---|---|---|---|---|---|
| Desensitising treatment | |||||
| Control | Isoprenaline | Formoterol | Salmeterol | ||
| Formoterol (1 μM) | 45±4 | 24±7* | 2±2* | 9±5* | |
| Salbutamol (1 μM) | 31±5 | 15±5 | 4±5* | 1±3* | |
| PGE2 (5 μM) | 43±5 | 45±6 | 43±5 | 44±5 | |
| Forskolin (5 μM) | 43±6 | 35±6 | 37±4 | 36±7 | |
| Theophylline (1 mM) | 65±4 | 55±4 | 53±5* | 50±7* | |
Cells were incubated (24 h) without (control) or with isoprenaline, formoterol or salmeterol (all at 10−6 M) and then washed extensively. The cells were then incubated with a cAMP-elevating compound for 10 min before challenge with anti-IgE (1 : 300) for a further 20 min for histamine release. Values are expressed as the % inhibition of the control histamine releases and these ranged from 29±3 to 34±1%. Values are means±s.e.m. from six experiments. Asterisks denote statistically different (P<0.05 at least) levels of inhibition, compared to control inhibition, following desensitising treatments.