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. 2012 Mar 15;8(3):e1002583. doi: 10.1371/journal.ppat.1002583

Figure 1. Effect of BoNT/A on longitudinal isometric muscle contraction from mouse ileal segments.

Figure 1

(A) Spontaneous ileal contraction frequency as a function of time under control conditions (black colums), and after BoNT/A (105 LD50/ml) injection into the lumen of ligated mouse ileal segments (white columns). BoNT/A (105 LD50/ml) was preincubated with GST-SV2C/L4 (20 µg/ml for 30 min at room temperature prior to being inoculated into ligated intestinal loop. Examples of spontaneous contractions before (B), and after 4 h of BoNT/A treatment (C). Note that BoNT/A significantly decreased, but not completely the frequency and amplitude of the spontaneous contractile activity. Data are from 3 independent experiments. (D). Time-dependent reduction of electrically-evoked longitudinal muscle contractions after BoNT/A injection into intestinal lumen. (E) Representative continuous control recording showing spontaneous contractions before and after single electrical field stimulation (30 Hz for 25 s, indicated by the trace below the evoked recording). Note the changes in spontaneous contractions following the evoked one. (F) In ileal segment treated for 4 h with BoNT/A, carbachol (20 µM) applied to the external medium (arrow) induced a sustained muscle contraction, indicating that ACh receptors were still functional. The line segment above the tension record indicates the time of carbachol application.