Figure 1.
Pilocarpine inhibits contraction of airway smooth muscle in vitro in response to electrical field stimulation (EFS, 15 Hz, 100 V, 0.2 ms pulse duration for 15 s at 1 min intervals) of isolated trachea. The pilocarpine concentration response curve was shifted to the left in diabetic rats, indicating that pilocarpine causes greater inhibition of EFS-induced contraction of tissues from diabetic rats than controls, although this did not reach statistical significance (P=0.3161). Data are expressed as the ratio of contraction after pilocarpine divided by the contraction before pilocarpine. Each point represents the mean and vertical bars show standard error of mean (n=8 – 9). The representative traces are from a control rat and show contractions to EFS before and after the addition of pilocarpine to the organ bath (at dots). At concentrations above 10−5 M, pilocarpine caused an increase in basal smooth muscle tone.