The calcium influx pathway in rat olfactory ensheathing cells shows TRPC channel pharmacology.

Pharmacological characterisation of the calcium influx pathway in olfactory ensheathing cells (OECs) was performed using Indo-1 calcium microfluorometry. Our previous work has implicated this pathway in olfactory ensheathing cell support for regeneration of axons from adult CNS neurons. In high extracellular calcium (20 mM), cumulative concentration inhibition curves were generated for Lu(3+), Gd(3+) and econazole, giving IC(50)s of 0.09, 1.51 and 1.13 microM, respectively, and slope values that were not significantly different from unity. Combining these results with those obtained previously, an order of inhibitor potency was found to be Lu(3+)>La(3+)=econazole=Gd(3+)>1-[2-(4-methoxyphenyl)-2-[3-(4-methoxyphenyl)propoxy]ethyl-1H-imidazole hydrochloride (SKF96365)>Cd(2+). This profile most closely fits some members of the TRPC family of non-voltage gated calcium influx channels and may indicate that a TRP-mediated calcium influx plays a role in glial-neuronal interaction and axonal regeneration.