Guanosine increases cGMP concentrations during guanosine-enhanced NGF-dependent neurite outgrowth in PC12 cells

<p><b>Copyright information:</b></p><p>Taken from "Guanosine stimulates neurite outgrowth in PC12 cells via activation of heme oxygenase and cyclic GMP"</p><p></p><p>Purinergic Signalling 2005;1(2):161-172.</p><p>Published online Jan 2005</p><p>PMCID:PMC2096532.</p><p></p> PC12 cells were cultured on plates coated with poly--ornithine for 72 h. Cells were then grown in serum-reduced medium (3% heat-inactivated fetal calf serum and 3% heat-inactivated horse serum) for 12 h, and were treated with guanosine (G, 300 µM) or NGF (N, 40 ng/ml) or guanosine (300 µM) plus NGF (40 ng/ml) (G + N), or with no added treatments (C) as described in Figure . Cells were lysed at time points 0, 6, 12, 24, and 48 h and cGMP concentrations were determined by a competitive enzyme immunoassay. Open bars: untreated controls (C), closed bars: guanosine plus NGF (G + N) treatment, stippled bars: NGF (N) treatment, hatched bars: guanosine (G) treatment. Statistical analysis was performed using a two-way ANCOVA followed by Fischer's LSD post-hoc comparison test (○ < 0.05, compared to time point 0); (* < 0.05, relative to control); (** < 0.01, relative to control); (Δ < 0.05, relative to NGF). Data presented represent the mean relative optical density T SEM obtained in six independent experiments