A quantitative approach to recording peristaltic activity from segments of rat small intestine in vivo

Abstract

We have developed methods that allow correlation of propulsive reflexes of the intestine with measurements of intraluminal pressure, fluid movement and spatio-temporal maps of intestinal wall movements for the first time in vivo. A segment of jejunum was cannulated and set up in a Trendelenburg recording system while remaining connected to the vascular and nerve supply of the anaesthetized rat. The resting intraluminal pressure in intact intestine was 2-4 mmHg. Hydrostatic pressures of 2, 4, 8 and 16 mmHg were imposed. At a baseline pressure of 4 mmHg, propulsive waves generated pressures of 9 +/- 1 mmHg, that progressed oral to anal at 2-5 mm s(-1). Individual propulsive waves propelled 0.8 +/- 0.4 mL of fluid. The frequency of propulsive waves increased with pressure, but peristaltic efficiency (mL per contraction) decreased with pressure increase between 4 and 16 mmHg. Atropine, as a bolus, transiently blocked peristalsis, but caused maintained block when infused. Hexamethonium blocked propulsive contractions. Inhibition of nitrergic transmission converted regular peristalsis to non-propulsive contractions. These studies demonstrate the utility of an adapted Trendelenburg method for quantitative investigation of motility and pharmacology of enteric reflexes in vivo.

Effects of feeding on in vivo motility patterns in the proximal intestine of shorthorn sculpin (Myoxocephalus scorpius)

“…Often, different patterns dominate in different regions of the gut, but this may also depend on the fed state of the animal (Ailiani et al, 2009;Berthoud et al, 2002;Bogeski et al, 2005;Chen et al, 2013;D'Antona et al, 2001;Ferens et al, 2005;Hennig et al, 1997;Hennig et al, 1999;Hennig et al, 2010). Mixing and propulsion can be achieved by either non-propagating (e.g.…”

Analysis of spatiotemporal pattern and quantification of gastrointestinal slow waves caused by anticholinergic drugs

“…The use of organ baths has a distinct advantage of allowing detailed analysis of motility through direct observation of the organ as a whole, and has been shown to have yield similar reflex reactions as in vivo experiments. 55 …”

“…Benztropine is used in the treatment of Parkinson disease, and promethazine is used in allergic rhinitis or as a sleep aid. Past studies have focused on threshold pressure for peristalsis and the occurrence of electrically stimulated evoked potentials, [55][56][57][58] rather than baseline contractile activity, which is our primary goal in this study. However, the effects of anticholinergics on slow waves, rather than peristalsis, has not been thoroughly tested.…”

“…57,58 Various effects were observed, including blockade of peristalsis, incomplete peristalsis, and increased intraluminal threshold pressure for peristalsis to occur. Past studies have focused on hexamethonium and atropine, [55][56][57] a nicotinic receptor antagonist and a muscarinic receptor antagonist respectively. These drugs are used mainly during anesthetic procedures, 35,59 and are not medications used by patients long-term.…”

“…In the literature, measurement of effects of anticholinergic agents on GI motility has focused around evoked potentials in response to electrophysiological nerve stimulation, and peristalsis, including measurements of number of complete peristalsis, and the interruption and cessation of peristalsis. [55][56][57][58] Measurement of slow waves in the literature has been undertaken mainly through electrophysiological studies. These include dissection of the organ to produce intact smooth muscle, which is then electrically stimulated with electrodes, as well as using cultured ICC and measuring the membrane potential changes to assess slow waves, known as the patch-clamp technique.…”