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The role of the dorsal vagal complex and the vagus nerve in feeding effects of melanocortin-3/4 receptor stimulation.
- Source :
-
Endocrinology [Endocrinology] 2000 Apr; Vol. 141 (4), pp. 1332-7. - Publication Year :
- 2000
-
Abstract
- Fourth intracerebroventricular (4th-icv) administration of the melanocortin-3/4 receptor (MC3/4-R) agonist, MTII, reduces food intake; the antagonist, SHU9119, increases feeding. The dorsal motor nucleus of the vagus nerve (DMX) contains the highest density of MC4-R messenger RNA in the brain. To explore the possibility that the DMX contributes to 4th-icv MC4-R effects, we delivered doses of MTII and SHU9119 that are subthreshold for ventricular response unilaterally through a cannula centered above the DMX. MTII markedly suppressed 2-h (50%), 4-h (50%), and 24-h (33%) intake. Feeding was significantly increased 4 h (50%) and 24 h (20%) after SHU9119 injections. These results suggest that receptors in the DMX, or the dorsal vagal complex more generally, underlie effects obtained with 4th-icv administration of these ligands. We investigated possible vagal mediation of 4th-icv MTII effects by giving the agonist to rats with subdiaphragmatic vagotomy. MTII suppressed 2-, 4-, and 24-h liquid diet intake (approximately 80%) to the same extent in vagotomized and surgical control rats. We conclude that stimulation or antagonism of MC3/4-Rs in the dorsal vagal complex yields effects on food intake that do not require an intact vagus nerve.
- Subjects :
- Animals
Body Weight
Drinking drug effects
Eating drug effects
Injections, Intraventricular
Male
Melanocyte-Stimulating Hormones pharmacology
Rats
Rats, Sprague-Dawley
Receptor, Melanocortin, Type 3
Receptor, Melanocortin, Type 4
Receptors, Corticotropin agonists
Reference Values
Vagotomy
Eating physiology
Receptors, Corticotropin physiology
Solitary Nucleus physiology
Vagus Nerve physiology
Subjects
Details
- Language :
- English
- ISSN :
- 0013-7227
- Volume :
- 141
- Issue :
- 4
- Database :
- MEDLINE
- Journal :
- Endocrinology
- Publication Type :
- Academic Journal
- Accession number :
- 10746636
- Full Text :
- https://doi.org/10.1210/endo.141.4.7410