Abnormal contractile properties of rectal smooth muscle in chronic ulcerative colitis

Abstract

Background: Patients with ulcerative colitis have abnormal rectal motility. Aim: To compare the contractile properties of rectal smooth muscle from patients with ulcerative colitis and controls. Methods: Rectal smooth muscle strips from patients undergoing resection for ulcerative colitis or cancer (control) were mounted in an organ bath. The effects of carbachol (receptor–mediated) and potassium (causes membrane depolarization) were studied. Acetylcholinesterase histochemistry was performed and nerve counts compared. Results: Ulcerative colitis (n=41) and control (n=34) strips contracted in response to potassium and carbachol. Mean (S.E.M.) maximum response to potassium in the control and ulcerative colitis groups was 1.07 (0.06) g/mg and 1.02 (0.09) g/mg tissue, respectively (P=N.S.). EC50s (concentrations required to give 50% of maximal response) were 75 (1) mM and 73 (1) mM, respectively (P=N.S.). Although maximum responses to carbachol were similar, 2.12 (0.12) g/mg and 1.95 (0.12) g/mg tissue (P=N.S.), ulcerative colitis strips exhibited an increased sensitivity to carbachol, EC50s: 5.05 × 10–6 (0.55 × 10–6) M vs. 8.36 × 10–6 (0.88 × 10–6) M, P=0.002). There was no significant difference in nerve counts between the tissues, as assessed by staining for acetylcholinesterase. Conclusions: Ulcerative colitis tissue has an increased sensitivity to carbachol and this is not due to denervation; it may result from increased calcium release from intracellular stores since contraction due to membrane depolarization is not altered. Modulation of this pathway could potentially be used to alter rectal motility in patients with ulcerative colitis.

Expression of iNOS mRNA associated with suppression of colonic contraction in rat colitis

“…Among those, studies in IBD patients claim defective colonic muscle contraction (Snape et al. 1991, Cook et al. 2000, Al‐Saffar & Hellström 2001), lowered luminal pressure (Reddy et al.…”

Acute Allergic Skin Reactions and Intestinal Contractility Changes in Mice Orally Sensitized against Casein or Whey

“…Motility measurements are often performed when studying inflammatory bowel diseases, in which similar intestinal symptoms can be found. In these studies, local intestinal inflammation is indicated as causative factor for motility changes reflecting alterations in smooth muscle contractions [48]. Hence, local intestinal inflammation may have induced hypomotility occurring in the casein mice.…”

Biomechanical changes in oxazolone-induced colitis in BALB/C mice

“…In contrast, Drewes et al (2006) suggested that smooth muscles are tonically contracted in the inflamed rectum, resulting in decreased circumference. Abnormal colonic smooth muscle contraction and abnormal interstitial cells of Cajal in patients with ulcerative colitis have been shown in several studies (Snape et al, 1991;Huizinga, 1988;Cook et al, 2000).…”