“In the presence of rolipram (10−5 M), basal 3H-cyclic AMP levels were approximately 70% higher than in its absence (basal: 1823 ± 57 dpm; rolipram: 3088 ± 229, n \2 = 3) and forskolin (3 × 10−5 M ) stimulated 3H-cyclic AMP accumulation approximately 8 fold.”