HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 290/1/R224    most recent 00442.2005v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (6) Citing Articles via Google Scholar Google Scholar Articles by Furlan, R. Articles by Malliani, A. Search for Related Content PubMed PubMed Citation Articles by Furlan, R. Articles by Malliani, A.

APPETITE, OBESITY, DIGESTION, AND METABOLISM

Sympathetic overactivity in active ulcerative colitis: effects of clonidine

¹Unità Sincopi, Medicina Interna II; and ²Gastroenterologia, ³Endocrinologia, and ⁴Anatomia Patologica, Ospedale L. Sacco, Dipartimento Scienze Cliniche L. Sacco, Università degli Studi di Milano, Milan, Italy

Submitted 22 June 2005 ; accepted in final form 24 August 2005

Previous reports suggest that inflammatory bowel diseases may be accompanied by abnormalities in the neural autonomic profile. We tested the hypotheses that 1) an exaggerated sympathetic activity characterizes active ulcerative colitis (UC) and 2) a reduction of sympathetic activity by clonidine would be associated with clinical changes of UC. In 23 patients with UC and 20 controls, muscle sympathetic nerve activity (MSNA), ECG, blood pressure, and respiration were continuously recorded, and plasma catecholamine was evaluated both at rest and during a 75° head-up tilt. Autonomic profile was assessed by MSNA, norepinephrine, epinephrine, spectral markers of low-frequency (LF) cardiac sympathetic (LF_RR; normalized units) and high-frequency (HF) parasympathetic (HF_RR; normalized units) modulation and sympathetic vasomotor control (LF systolic arterial pressure; LF_SAP), obtained by spectrum analysis of the R-R interval and systolic pressure variability. Among UC patients, 16 agreed to be randomly assigned to 8-wk transdermal clonidine (15 mg/wk, 9 subjects), or placebo (7 patients). An autonomic profile, Disease Activity Index (DAI), and endoscopic pattern were compared before and after clonidine/placebo. At rest, MSNA, heart rate (HR), LF_RR, LF/HF, and LF_SAP were higher and HF_RR was lower in patients than in controls. Tilt decreased HF_RR and increased MSNA and LF_RR less in patients than in controls. Clonidine decreased HR, MSNA, epinephrine, LF_RR, and increased HF_RR, whereas placebo had no effects. Changes of the autonomic profile after clonidine were associated with reduction of DAI score. An overall increase of sympathetic activity characterized active UC. Normalization of the autonomic profile by clonidine was accompanied by an improvement of the disease.

sympathetic nervous system; microneurography; power spectrum analysis; tilt test

This article has been cited by other articles:

				G. Parati, G. Mancia, M. D. Rienzo, P. Castiglioni, J. A. Taylor, and P. Studinger Point:Counterpoint: Cardiovascular variability is/is not an index of autonomic control of circulation J Appl Physiol, August 1, 2006; 101(2): 676 - 682. [Abstract] [Full Text] [PDF]