| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
NEUROREGULATION AND MOTILITY
Center of Swallowing and Motility Disorders, Department of Veterans Affairs Medical Center, West Roxbury; and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
Submitted 7 January 2005 ; accepted in final form 12 April 2005
Nitric oxide (NO) relaxes the internal anal sphincter (IAS), but its enzymatic source(s) remains unknown; neuronal (nNOS) and endothelial (eNOS) NO synthase (NOS) isoforms could be involved. Also, interstitial cells of Cajal (ICC) may be involved in IAS relaxation. We studied the relative roles of nNOS, eNOS, and c-Kit-expressing ICC for IAS relaxation using genetic murine models. The basal IAS tone and the rectoanal inhibitory reflex (RAIR) were assessed in vivo by a purpose-built solid-state manometric probe and by using wild-type, nNOS-deficient (nNOS–/–), eNOS-deficient (eNOS–/–), and W/Wv mice (lacking certain c-Kit-expressing ICC) with or without L-arginine or N
-nitro-L-arginine methyl ester (L-NAME) treatment. Moreover, the basal tone and response to electrical field stimulation (EFS) were studied in organ bath using wild-type and mutant IAS. In vivo, the basal tone of eNOS–/– was higher and W/Wv was lower than wild-type and nNOS–/– mice. L-Arginine administered rectally, but not intravenously, decreased the basal tone in wild-type, nNOS–/–, and W/Wv mice. However, neither L-arginine nor L-NAME affected basal tone in eNOS–/– mice. In vitro, L-arginine decreased basal tone in wild-type and nNOS–/– IAS but not in eNOS–/– or wild-type IAS without mucosa. The in vivo RAIR was intact in wild-type, eNOS–/–, and W/Wv mice but absent in all nNOS–/– mice. EFS-induced IAS relaxation was also reduced in nNOS–/– IAS. Thus the basal IAS tone is largely controlled by eNOS in the mucosa, whereas the RAIR is controlled by nNOS. c-Kit-expressing ICC may not be essential for the RAIR.
basal internal anal sphincter tone; electrical field stimulation; internal anal sphincter; nitric oxide synthases; rectoanal inhibitory reflex
This article has been cited by other articles:
|
|
 |
|
  B. McDonnell, R. Hamilton, M. Fong, S. M. Ward, and K. D. Keef Functional evidence for purinergic inhibitory neuromuscular transmission in the mouse internal anal sphincter Am J Physiol Gastrointest Liver Physiol, April 1, 2008; 294(4): G1041 - G1051. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Katsui, Y. Kojima, H. Kuniyasu, J. Shimizu, F. Koyama, H. Fujii, Y. Nakajima, and M. Takaki A new possibility for repairing the anal dysfunction by promoting regeneration of the reflex pathways in the enteric nervous system Am J Physiol Gastrointest Liver Physiol, April 1, 2008; 294(4): G1084 - G1093. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Sarna Are interstitial cells of Cajal plurifunction cells in the gut? Am J Physiol Gastrointest Liver Physiol, February 1, 2008; 294(2): G372 - G390. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. F. de Godoy and S. Rattan Role of phospholipase A2 (group I secreted) in the genesis of basal tone in the internal anal sphincter smooth muscle Am J Physiol Gastrointest Liver Physiol, November 1, 2007; 293(5): G979 - G986. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. Alberti, H. B. Mikkelsen, X. Y. Wang, M. Diaz, J. O. Larsen, J. D. Huizinga, and M. Jimenez Pacemaker activity and inhibitory neurotransmission in the colon of Ws/Ws mutant rats Am J Physiol Gastrointest Liver Physiol, June 1, 2007; 292(6): G1499 - G1510. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. Dixit, N. Zarate, L. W. C. Liu, D. R. Boreham, and J. D. Huizinga Interstitial cells of Cajal and adaptive relaxation in the mouse stomach Am J Physiol Gastrointest Liver Physiol, December 1, 2006; 291(6): G1129 - G1136. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
