Kinetics of kyotorphin- and GppNHp-evoked45Ca2+ release from resealed SPM vesicles and involvements of PTX substrate G-proteins and PLC. A, Kyotorphin- and/or GppNHp-evoked45Ca2+ release were represented as with InsP3-evoked increase (%) in the 45Ca2+ release (see Results). B, Double-reciprocal plots of evoked45Ca2+ release by various combinations of kyotorphin and GppNHp. C, Effects of PTX (50 μg/ml) pretreatments of SPM on 100 μmkyotorphin (plus 10 μm GppNHp)-evoked45Ca2+ release.D, Blockade of kyotorphin (plus 10 μm GppNHp)-evoked45Ca2+ release by pretreatments of SPM with various concentrations of PTX. E, Effects of neomycin (0.3 mm) on 100 μm kyotorphin (plus 10 μm GppNHp)-evoked45Ca2+ release.F, Concentration-dependent inhibition of 100 μm kyotorphin (plus 10 μm GppNHp)-evoked45Ca2+ release by neomycin.