6-OHDA-Induced Changes in Colonic Segment Contractility in the Rat Model of Parkinson’s Disease

Figure 3

Contractions of distal colon segments and inverted segments following electrical field stimulation (EFS) and methacholine in the absence and presence of the nitric oxide synthase inhibitor L-NAME. Significant and similar reduced contractile responses in EFS by L-NAME were observed in the segments in both Sham () and 6-OHDA animals (; a). However, L-NAME reduced the methacholine-mediated contractility in the 6-OHDA animals (), but not in the Sham group (; b). The inverted segments showed significant increased responses to EFS (c) and methacholine (d) in the 6-OHDA () as compared with Sham group () in the absence of L-NAME. In the presence of L-NAME the EFS response showed no difference within respective groups, but a trend to decrease could be seen in the 6-OHDA animals. The methacholine response on the other side was significantly increased in the Sham group after L-NAME. The increase was however, not significant in the 6-OHDA animals. *Significant difference from Sham group; # = significant difference between presence and absence of L-NAME in respective group. Two-way ANOVAs (a) * = group ; and # = group , ; , for Sham and 6-OHDA, respectively; (b) * = group , and # = group for 6-OHDA; (c): * = group , ; (d) * = group , ; # = , for Sham. The data here are representing a subset of the data included in Figures 2(e) and 2(f).