TY - JOUR
T1 - Coloanal motor coordination in association with high-amplitude colonic contractions after pharmacological stimulation
AU - Malcolm, Allison
AU - Camilleri, Michael
N1 - Funding Information:
This study was supported in part by General Clinical Research Center grant #RR00585 from National Institutes of Health. Dr. Camilleri is supported by NIH R01-DK54681–01 and K24-DK02638. We thank Mrs. Cindy Stanislav for secretarial support. Dr. Malcolm’s current address: Department of Gastroenterology, Royal North Shore Hospital, St. Leonards, Sydney 2065, Australia.
PY - 2000/3
Y1 - 2000/3
N2 - OBJECTIVE: The rectoanal inhibitory reflex facilitates defecation by relaxation of the internal anal sphincter during rectal distention by gas or stool. Defecation is sometimes preceded by high-amplitude propagated contractions (HAPCs). Our objective was to seek evidence for motor coordination between human colonic and anal sphincter functions. METHODS: As part of a study of α2 modulation of colonic and anal motor functions in 32 healthy volunteers, we studied the relationship between high HAPCs and anal sphincter pressure with colonic manometry, barostat, and a Dent sleeve in the anal canal. RESULTS: Twenty-two HAPCs were observed; in 19/22 HAPCs there was optimal positioning of the Dent sleeve to assess the anal sphincter. Eighteen of 19 HAPCs occurred postprandially; 14 HAPCs occurred after administration of yohimbine, three after clonidine, and one before any drug administration. Seven followed experimental balloon distention. Anal sphincter relaxation occurred (14 ± 4 s) before the recorded onset of HAPC in the descending colon and 88 ± 7 s before the arrival of the HAPC in the rectum. After or during the HAPCs, anal sphincter pressure decreased by 40 ± 4% and increased by 56 ± 8% in the postrelaxation phase. CONCLUSIONS: The close temporal association between anal sphincter relaxation and onset of HAPC in the descending colon suggests a coloanal reflex that may facilitate defecation during mass movements independently of the rectoanal inhibitory reflex. (C) 2000 by Am. Coll. of Gastroenterology.
AB - OBJECTIVE: The rectoanal inhibitory reflex facilitates defecation by relaxation of the internal anal sphincter during rectal distention by gas or stool. Defecation is sometimes preceded by high-amplitude propagated contractions (HAPCs). Our objective was to seek evidence for motor coordination between human colonic and anal sphincter functions. METHODS: As part of a study of α2 modulation of colonic and anal motor functions in 32 healthy volunteers, we studied the relationship between high HAPCs and anal sphincter pressure with colonic manometry, barostat, and a Dent sleeve in the anal canal. RESULTS: Twenty-two HAPCs were observed; in 19/22 HAPCs there was optimal positioning of the Dent sleeve to assess the anal sphincter. Eighteen of 19 HAPCs occurred postprandially; 14 HAPCs occurred after administration of yohimbine, three after clonidine, and one before any drug administration. Seven followed experimental balloon distention. Anal sphincter relaxation occurred (14 ± 4 s) before the recorded onset of HAPC in the descending colon and 88 ± 7 s before the arrival of the HAPC in the rectum. After or during the HAPCs, anal sphincter pressure decreased by 40 ± 4% and increased by 56 ± 8% in the postrelaxation phase. CONCLUSIONS: The close temporal association between anal sphincter relaxation and onset of HAPC in the descending colon suggests a coloanal reflex that may facilitate defecation during mass movements independently of the rectoanal inhibitory reflex. (C) 2000 by Am. Coll. of Gastroenterology.
UR - http://www.scopus.com/inward/record.url?scp=0033995571&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0033995571&partnerID=8YFLogxK
U2 - 10.1016/S0002-9270(99)00899-0
DO - 10.1016/S0002-9270(99)00899-0
M3 - Article
C2 - 10710063
AN - SCOPUS:0033995571
SN - 0002-9270
VL - 95
SP - 715
EP - 719
JO - American Journal of Gastroenterology
JF - American Journal of Gastroenterology
IS - 3
ER -