Search

Cilostazol, a specific cAMP phosphodiesterase III inhibitor, is used for medical treatment of intermittent claudication in peripheral artery disease to prevent leg pain during physical activity. Dorsal root ganglion (DRG) neurons are eligible experimental model for pain investigations. Aim of this study was to figure out the effect of cilostazol on intracellular calcium ([Ca2+]i) signaling in cultured rat DRG neurons. DRG neurones were grown in primary culture following enzymatic and mechanical dissociation of ganglia from 2-day-old Wistar rats. DRG neuronal cultures were loaded with 1µmol Fura-2AM and [Ca2+]i responses to stimulation were assessed by using fluorescent ratiometry. Cultured cells were excited at 340 and 380nm, and emission was recorded at 510nm. Responses were determined by the change in 340/380 ratio (basal-peak) for individual neurons. After basal recordings, KCl (30mM) and capcaicin (1µ,M) applied to medium for induction of [Ca2+]i . Cilostazol treated alone or co-administered with KCl and capcaicin for determining the possible changes in calcium signaling. Data were analyzed by using one-way analysis of variance followed by a post-hoc Tukey HSD test, with a 2-tailed P level of <0.05 defining statistical significance. Firstly exposure to cilostazol failed to cause any significant change in basal [Ca2+]i response (basal=100.0±0.0 and cilostazol =99.8±0.2 %). KCl and capcaicin had significant increase in [Ca2+]i responses to 164.71 ±4.1 % and 191.55±6.4 % (respectively, p< 0.001). But co-application of cilostazol with KCl and capcaicin didnot alter the KCl and capcaicin induced elevation in [Ca2+]i (166.14±3.7 % and 188.26±4.7 %, respectively). In conclusion, the results of present study suggest that cilostazol has no effect on [Ca2+]i signaling in rat sensory neurons in vitro. It seems cilostazol may activate other mechanism(s) at cellular level rather than modulating calcium signaling in DRG neurons. [ABSTRACT FROM AUTHOR]