FIG. 2.

Sildenafil significantly increases spinal cord cyclic guanosine monophosphate (cGMP). Intravenous injection of 10 mg/kg sildenafil significantly increased cGMP levels after 45 min in uninjured (black bars) spinal cord homogenates as assessed by enzyme immunoassay (saline-treated, n=3; sildenafil-treated, n=4; *p<0.05). Intravenous injection and twice-daily IP injection of 5 mg/kg sildenafil for 7 days following moderate contusive injury similarly increased cGMP levels in contusion epicenters (grey bars). Data are means±standard error of the mean (saline-treated, n=5; sildenafil-treated, n=5; *p<0.05).