TABLE 3.
Summary of inhibitors used to identify signaling pathways involved in [Ca2+]e- and [Sr2+]e-stimulated calcitonin secretion
| Inhibitor | Mode of Action | Relative Selectivity |
|---|---|---|
| U73122 | Noncompetitive inhibitor of PI-PLC (Smallridge et al., 1992) | Other effects have been reported, including inhibition of adenosine A1 receptor (Walker et al., 1998) and plasma membrane Ca2+ channels (Berven and Barritt, 1995; Pulcinelli et al., 1998) |
| ET-18-OCH3 | Inhibitor of PI-PLC (Powis et al., 1992) | Activity on platelet-activating factor receptor and Fas/CD95 has been well described (Mollinedo et al., 2004) |
| 2-APB | Modulator of IP3 receptor on intracellular calcium stores (Maruyama et al., 1997) | Other effects have been reported, including uncoupling of gap junction channels formed by certain connexins (Bai et al., 2006) |
| Nimodipine | L-type calcium channel blocker (McGehee et al., 1997) | Has been demonstrated to inhibit equilibrative nucleotide transporter-1 and amyloid β-stimulated IL-1β release (Li et al., 2012; Sanz et al., 2012) |
| BAPTA-AM | Chelator of intracellular divalent cations with high selectivity for [Ca2+]i (Tsien, 1980; Wie et al., 2001) | Other effects have been reported, including calcium-independent cytoskeleton disassembly (Saoudi et al., 2004) |
| D609 | Competitive inhibitor of PC-PLC (Farooqui and Horrocks, 2005) | Has been reported to inhibit sphingomyelin synthase and glucosylceramide synthase (Milhas et al., 2012) |
| Pertussis toxin | Inhibitor of ADP-ribosylation of Gi/o proteins (Mangmool and Kurose, 2011) | Other effects are known, including binding and activation of membrane receptors such as Toll-like receptor 4 (Mangmool and Kurose, 2011) |
| PD98059 | Noncompetitive inhibitor of MEK (Akella et al., 2008) | Controversy exists over whether PD98059 has nonspecific effects on voltage-sensitive calcium channels (Hu et al., 1998; Lagaud et al., 1999) |
| Wortmannin | Noncompetitive inhibitor of PI-3K (Stein, 2001) | Shows poor selectivity among different PI-3K isoforms (Stein, 2001) |
| LY294002 | Competitive inhibitor of PI-3K (Stein, 2001) | Has been reported to inhibit casein kinase 2 and mammalian target of rapamycin and displays poor selectivity among different PI-3K isoforms (Stein, 2001) |