Analgesic effects of JCM-16021 on neonatal maternal separation-induced visceral pain in rats

Figure 1 Pain threshold pressure assessment in different groups. Data are presented as the mean ± SE. Before treatment, the pain threshold of NMS groups was significantly decreased, as compared with that of the NH-VH group (^bP < 0.001). After treatment, JCM-16021 and Holopon significantly increased the pain threshold pressure (^aP < 0.05, ^dP < 0.01, ^fP < 0.001) compared with that before treatment of each group.

Figure 2 JCM-16021 effect on the electromyographic activity in response to graded CRD at pressures of 20 mmHg (A), 40 mmHg (B), 60 mmHg (C), 80 mmHg (D). Data are presented as mean ± SE (n = 7-10). Significant difference is indicated by ^aP < 0.05 when compared with the NMS-VH group.

Figure 3 JCM-16021 effects on the concentrations of 5-HT and 5-HIAA in the colons of rats. A: JCM-16021 significantly decreased 5-HT concentration in neonatal maternal separation (NMS) rats; B: JCM-16021 significantly increased 5-HIAA concentration in NMS rats. Data are presented as mean ± SE (ng/100 mg colon tissue, n = 8-10). Significant difference is indicated by ^aP < 0.05 when compared with the NH control group and by ^cP < 0.05 when compared with the NMS control group.

Figure 4 JCM-16021 effect on enterochromaffin cell number (Chr A positive cell number) in the colons of rats. Chr A staining cells (arrows) are present in colon tissues in the normal control group (A), the NMS control group (B), the NMS with high dosage (C), the NMS with middle dosage (D), and the NMS with low dosage of JCM-16021 (E). NMS significantly increased the number of Chr A positive cells in the colons of rats, and JCM-16021 did not change the number of Chr A positive cells (F). Data are presented as mean ± SE (n = 8-10). Significant difference is indicated by ^aP < 0.05 compared with the normal control group.

Figure 5 SERT expression in rat colon by immunohistochemistry assay. SERT expression in the colonic tissues of NMS rats was significantly increased over that of NH rats. JCM-16021 treatment decreased SERT expression. Results are expressed as mean ± SE, n = 8-10 in each group. ^aP < 0.05, ^bP < 0.01, ^dP < 0.001 vs NH.