Motor responses of the small intestine to intraluminal distension in normal volunteers and a patient with visceral neuropathy.

Abstract

SUMMARY The motor responses of the small intestine to intraluminal distension were studied proximal and distal to an inflatable balloon in 13 normal volunteers. During fasting, distension rapidly induced a persistent localised inhibition of distal contractile activity with a small proximal increase. Proximally, phase III activity was unaffected during distension but its propagation across and appearance below the balloon was inhibited. Upon deflating the balloon a normal motor pattern rapidly returned. Similar changes were observed during distension in the fed state. The changes in the motor pattern resemble those of the intrinsically mediated 'peristaltic reflex', studied in animals, and suggest that in man the response to balloon distension may also be mediated through an intrinsic mechanism. A patient with a visceral neuropathy, studied in a similar manner, had no inhibition of distal motor activity during distension, suggesting a functional defect of the enteric nerves. Further observations of the motor responses to distension in similar patients seem indicated to determine the usefulness of this technique for evaluating enteric nervous system function when an abnormality is suspected.

Manometric responses of human duodenum during infusion of HCl, hyperosmolar saline, bile and oleic acid

“…Ten healthy volunteers (five male, five female] participated in this study. The mean age was 24 years (range [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34]. Written informed consent was obtained from all subjects under guidelines approved by the Human Research Committee of the University of Iowa Hospitals and Clinics, and the Radiation Protection Committee, M 1080, April 4, 1993.…”

On the modeling of intestinal segment motion

“…Such a modified model describes a wide range of situations, including the normal intestinal phenomena [1,11], physiological experiments [2], and the behavior of surgically formed reservoirs [12] . It permits a number of useful modifications, for example, taking into account the dependence of the valve function threshold on the parameters characterizing the reservoir state and the external action .…”

“…2 = const, 1 < a, < 2, a2 = a' E 1 < E The representation N=Non(0) may be adopted, where n(0) has a characteristic bell-shaped form [1,2] . (1 .4), in which the active stress component N depends on two parameters : the calcium activation level yE [0, 1] and the measure of the relative position of the microfilaments A O = ale -aZ6, a l .…”

“…One of these is the myogenic mechanism, i .e ., the ability of the muscles to become activated when stretched [1,2] . One of these is the myogenic mechanism, i .e ., the ability of the muscles to become activated when stretched [1,2] .…”

Quantification of the oesophageal peristaltic reflex in man

“…We investigated the peristaltic reflex in eight healthy volunteers (aged [19][20][21][22][23][24][25] years; five male, three female) by two series of eight graded (3)(4)(5)(6)(7)(8)(9)(10) mL) balloon distensions performed 11 cm above the LOS, monitoring motor activity in the oesophageal body both above and below the balloon and in the LOS (sleeve sensor).…”