| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Veterinary and Comparative Anatomy, Pharmacology, and Physiology, College of Veterinary Medicine, Washington State University, Pullman, WA, USA
* To whom correspondence should be addressed. E-mail: petersj{at}vetmed.wsu.edu.
The hormone leptin and the gut-peptide cholecystokinin (CCK) synergistically interact to enhance the process of satiation. While this interaction may occur at several levels of the neuroaxis, our previous results indicate that leptin can specifically enhance the satiation effect of CCK by acting on subdiaphragmatic vagal afferent neurons. Because of this localized action we hypothesized that a high proportion of vagal afferent neurons innervating the stomach or duodenum would be responsive to leptin and/or CCK. To test this hypothesis we measured changes in cytosolic calcium levels induced by leptin and CCK in cultured nodose ganglion neurons labeled with a retrograde neuronal tracer injected into either the stomach or the duodenum. In the neurons labeled from the stomach CCK activated 74% (39 of 53,) compared to only 35% (34 of 97) of nonlableled cells. Of the CCK responsive neurons 60% (18 of 30) were capsaicin-sensitive. Leptin activated 42% (22 of 53) of the stomach innervating neurons compared to 26% of non-labeled neurons. All of the leptin-sensitive neurons labeled from the stomach also responded to CCK. In the neurons labeled from the duodenum CCK activated 71% (20 of 28). Of these CCK responsive neurons 80% (12 of 15) were capsaicin-sensitive. Leptin activated 46% (13 of 28) of these duodenal innervating neurons, of which 89% (8 of 9) were capsaicin-sensitive. Among neurons labeled from the duodenum 43% (12 of 28) were responsive to both leptin and CCK, compared to only 15% (15 of 97) of unlabeled neurons. Our results support the hypothesis that vagal afferent sensitivity to CCK and leptin is concentrated in neurons that innervate the stomach and duodenum. These specific visceral afferent populations are likely to comprise a substrate through which acute leptin / CCK interactions enhance satiation.
This article has been cited by other articles:
|
|
 |
|
  A. M. van den Hoek, C. van Heijningen, J. P. Schroder-van der Elst, D. M. Ouwens, L. M. Havekes, J. A. Romijn, A. Kalsbeek, and H. Pijl Intracerebroventricular Administration of Neuropeptide Y Induces Hepatic Insulin Resistance via Sympathetic Innervation Diabetes, September 1, 2008; 57(9): 2304 - 2310. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Chearskul, E. Delbridge, A. Shulkes, J. Proietto, and A. Kriketos Effect of weight loss and ketosis on postprandial cholecystokinin and free fatty acid concentrations Am. J. Clinical Nutrition, May 1, 2008; 87(5): 1238 - 1246. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Guijarro, S. Suzuki, C. Chen, H. Kirchner, F. A. Middleton, S. Nadtochiy, P. S. Brookes, A. Niijima, A. Inui, and M. M. Meguid Characterization of weight loss and weight regain mechanisms after Roux-en-Y gastric bypass in rats Am J Physiol Regulatory Integrative Comp Physiol, October 1, 2007; 293(4): R1474 - R1489. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T.-L. Li, L.-C. Chiou, Y. S. Lin, J.-R. Hsieh, and L.-L. Hwang Electrophysiological study on the effects of leptin in rat dorsal motor nucleus of the vagus Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2007; 292(6): R2136 - R2143. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. J. Page, J. A. Slattery, C. Milte, R. Laker, T. O'Donnell, C. Dorian, S. M. Brierley, and L. A. Blackshaw Ghrelin selectively reduces mechanosensitivity of upper gastrointestinal vagal afferents Am J Physiol Gastrointest Liver Physiol, May 1, 2007; 292(5): G1376 - G1384. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Covasa CCK- and leptin-induced vagal afferent activation: a model for organ-specific endocrine modulation of visceral sensory information Am J Physiol Regulatory Integrative Comp Physiol, June 1, 2006; 290(6): R1542 - R1543. [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
