FIG. 5.

Effects of prolonged rapamycin (RAP) treatment on mean arterial pressure (MAP) and heart rate (HR) during colorectal distension (CRD). (A) In naïve rats, RAP treatment did not affect the extent of CRD-induced MAP change relative to baseline at any time point. Spinal cord injury (SCI) alone significantly attenuated the extent of CRD-induced MAP changes at 14 and 21 days post-injury (DPI), but RAP treatment after SCI did not alter the extent of MAP response to CRD at any time point. (B) Naïve rats responded to CRD with tachycardia, whereas injured rats displayed bradycardia that is characteristic of AD. While the HR responses to CRD were diametrically opposite in injured compared with naïve rats at all DPI, RAP treatment did not alter the extent of CRD-induced HR changes in either naïve or SCI groups. (C) RAP treatment did not alter the baseline MAP in naïve rats at any time point. SCI significantly reduced the baseline MAP compared with the naïve + vehicle group at 14, 21, and 28 DPI, however. In SCI rats, RAP significantly increased the baseline-MAP to naïve levels compared with the SCI + vehicle group at 14 and 21 DPI. (D) The absolute MAP reached during CRD was lower in SCI rats at all time points. Whereas RAP treatment had no effects in naïve rats, it significantly increased the CRD-induced MAP in injured rats at 21 DPI. n = 3 naïve + vehicle; n = 3 naïve + RAP (3 mg/kg); n = 7 SCI + vehicle; n = 7 SCI + RAP (3 mg/kg). Symbols are means ± standard deviation. *p < 0.05 vs. naïve + vehicle; #p < 0.05 vs. SCI + vehicle.