|
|
||||||||
Gastroenterology Research Unit, Department of Internal Medicine, The University of Michigan Health System, Ann Arbor, Michigan 48109-0362
We have demonstrated that under physiological conditions CCK acts through vagal high-affinity CCK-A receptors to mediate pancreatic secretion. In this study, we evaluated the vagal afferent response to endogenous CCK in rats and defined the CCK-receptor affinity states and the vagal-receptive field responsive to CCK stimulation using electrophysiological studies. Experiments were performed on anesthetized rats prepared with bile-pancreatic fistula. Plasma CCK levels were elevated by diverting bile-pancreatic juice (BPJ). The single-unit discharge of sensory neurons supplying the gastrointestinal tract was recorded from the nodose ganglia. All units studied were either silent or they had a very low resting discharge frequency. Thirty-two single units were studied extensively; seven were shown to be stimulated by diversion of BPJ (2.6 ± 2 impulses/min at basal to 40 ± 12 impulses/min after diversion). Acute subdiaphragmatic vagotomy or perivagal capsaicin treatment abolished the response. The CCK-A-receptor antagonist CR-1409, but not the CCK-B antagonist L-365260, blocked the vagal response to endogenous CCK stimulation. Infusion of the low-affinity CCK-receptor antagonist CCK-JMV-180 completely blocked the vagal afferent response to the diversion of BPJ in three of seven rats tested but had no effect on the response in the remaining four. In a separate study, we demonstrated that gastric, celiac, or hepatic branch vagotomy abolished the response in different subgroups of neurons. In conclusion, under physiological conditions, CCK acts on both high- and low-affinity CCK-A receptors present on distinct vagal afferent fibers. The vagal CCK-receptor field includes the regions innervated by the gastric, celiac, and hepatic vagal branches. This study provides electrophysiological evidence that vagal CCK receptors are present on the vagal gastric, celiac, and hepatic branches and may occur in high- and low-affinity states.
nodose ganglia; cholecystokinin-JMV-180; selective branch vagotomy
This article has been cited by other articles:
![]() |
B. J. Wang and Z. J. Cui How does cholecystokinin stimulate exocrine pancreatic secretion? From birds, rodents, to humans Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2007; 292(2): R666 - R678. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Sartor, A. Shulkes, and A. J. M. Verberne An enteric signal regulates putative gastrointestinal presympathetic vasomotor neurons in rats Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2006; 290(3): R625 - R633. [Abstract] [Full Text] [PDF] |
||||
![]() |
Y. Li, X. Wu, H. Yao, and C. Owyang Secretin activates vagal primary afferent neurons in the rat: evidence from electrophysiological and immunohistochemical studies Am J Physiol Gastrointest Liver Physiol, October 1, 2005; 289(4): G745 - G752. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. M. Savastano, M. Carelle, and M. Covasa Serotonin-type 3 receptors mediate intestinal Polycose- and glucose-induced suppression of intake Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2005; 288(6): R1499 - R1508. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Wu, J. Gao, J. Yan, C. Owyang, and Y. Li Hypothalamus-Brain Stem Circuitry Responsible for Vagal Efferent Signaling to the Pancreas Evoked By Hypoglycemia in Rat J Neurophysiol, April 1, 2004; 91(4): 1734 - 1747. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. M. Simasko and R. C. Ritter Cholecystokinin activates both A- and C-type vagal afferent neurons Am J Physiol Gastrointest Liver Physiol, December 1, 2003; 285(6): G1204 - G1213. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. M. Simasko, J. Wiens, A. Karpiel, M. Covasa, and R. C. Ritter Cholecystokinin increases cytosolic calcium in a subpopulation of cultured vagal afferent neurons Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2002; 283(6): R1303 - R1313. [Abstract] [Full Text] [PDF] |
||||
![]() |
X. Deng, D. R. Guarita, M. R. A. Pedroso, C. Kreiss, P. G. Wood, A. F. Sved, and D. C. Whitcomb PYY inhibits CCK-stimulated pancreatic secretion through the area postrema in unanesthetized rats Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2001; 281(2): R645 - R653. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |