Figure 8.

Calcium mobilization by cADPR and IP₃ from microsomes of C57BL/6J, ob/ob islets, and RINm5F β-cells (adapted from Ref. 89). A. Ca²⁺ release from microsomes (10 µg of protein) was induced by the addition of 100 nM cADPR or 1 µM IP₃ in the presence of 7 µg/mL calmodulin.^83,103) Values are mean ± S.E. of triplicate experiments. The inset shows a typical result of Ca²⁺ release from C57BL/6J mouse islet microsomes. The Ca²⁺ release by cADPR was not affected by the pre-addition of IP₃, as seen in rat islet microsomes.⁸⁹⁾ B. RT-PCR analyses of C57BL/6J and ob/ob islets. Expression of RyR and IP₃R mRNAs.