Figure 4. Heparin partially inhibits cADPr-dependent Ca²⁺ release.

(B) Activation of the caged cADPr pre-injected in A. aranciacus eggs results in intracellular release of Ca²⁺. The altitude of the Ca²⁺ peak was significantly reduced in heparin-treated eggs compared to the control (n = 7, in each case). (B) Transmission photomicrographs of control and heparin-treated eggs following cADPr uncaging (450 µM, pipette concentration) and subsequent Ca²⁺ release. The typical elevation of the vitelline layer seen in the control eggs (arrow) was absent in the eggs treated with heparin.