1
The U46619-induced platelet aggregation was inhibited by Z-335 in a noncompetitive manner, while it was competitively inhibited by SQ29548.
2
The 5-HT-induced contraction was potently inhibited by compounds with high affinity at the 5-HT2 site in an apparently noncompetitive manner.
3
This idea was supported by the fact that the phosphodiesterase inhibitor 1-isobutyl 3-methylxanthine blocked attenuation of cyclic AMP accumulation by histamine in a noncompetitive manner.