Table 1

Characteristics of cell surface and internalized125I-helodermin binding in CHO cells expressing VPAC1and VPAC2 receptors

VPAC1VPAC2
ExternalInternalExternalInternal
IC50 helodermin (nM)1.02  ± 0.350.92  ± 0.173.05  ± 0.521.72  ± 0.24
B max (pmol/mg protein)0.07  ± 0.010.21  ± 0.021.23  ± 0.342.77  ± 0.61