Rectal tone, distensibility and mechanoperception: intraindividual
reproducibility and responses to different distension protocols.
Hammer, H. F., S. F. Phillips, M. Camilleri, R. B. Hanson.
Gastroenterology Research Unit, Mayo Clinic and Mayo Foundation,
Rochester, MN. Medizinische Klinik, Karl-Franzens
-Universit[umlaut]at, Auenbruggerplatz 15, A-8036, Graz, Austria.
APStracts 4:0311G, 1997.
Increasing interest is focusing on the role of intestinal tone,
distensibility, and mechanosensation in the genesis of abdominal
symptoms. Experimental approaches usually feature balloon distension
of the bowel with measurements of perception, tone, and
compliance/elastance; however, the methodologies are standardized
incompletely. We examined the reproducibility of repeated assessments
of sensory perception, basal tone, and compliance/elastance of the
rectum during distension. We also evaluated the response to
inflations that varied in regard to control of pressure or volume,
pattern of distension, and rate of inflation. Five healthy volunteers
were studied under two separate protocols. The first featured a
series of experiments on each of five days; the other consisted of
two separate days of study. Repeated distensions evoked reproducible
responses of sensation and compliance/elastance on a single day,
providing a conditioning distension preceded them. Day-to-day
variability was also sufficiently small to allow valid comparisons to
be made on different days in healthy persons. The configuration of
the distension profile (phasic, staircase, or ramp) and the rate of
inflation (from 1 ml/second to 40 ml/second) had little effect on
distensibility or perception. Perceptions were sometimes transient
and sometimes constant, but no relationship was found between these
temporal features and the magnitude of the stimulus. These
observations help provide a basis as to how the responses to rectal
distension can be best studied.
Received 7 April 1997; accepted in final form 17 December 1997.
APS Manuscript Number G127-7.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 7 January 1998