Figure 3.

Effects of in vitro furaldipine on basal (IBMX) and forskolin-stimulated cyclic AMP production in the different experimental groups. Cyclic AMP was determined in brain cortex slices incubated for 10 min with 10 μM forskolin alone or with 1 μM furaldipine. Control animals were treated with saline (1 μl h⁻¹) for 7 days. Tolerant animals received sufentanil (2 μg h⁻¹) for 7 days. Supersensitive animals were concurrently treated with sufentanil (2 μg h⁻¹) and nimodipine (1 μg h⁻¹) for 7 days. Data are expressed as mean±s.e.mean. ^*P<0.05 vs forskolin (Student t-test).