Peripheral ghrelin enhances sweet taste food consumption and preference, regardless of its caloric content.
OBJECTIVE
Ghrelin is one of the most potent orexigens known to date. While the prevailing view is that ghrelin participates in the homeostatic control of feeding, the question arose as to whether consummatory responses evoked by this compound could be related to search for reward. We therefore attempted to delineate the involvement of ghrelin in the modulation of non-caloric but highly rewarding consumption.


METHODS
We tested the effect of intraperitoneally injected ghrelin on the acceptance and preference for a 0.3% saccharin solution using single bottle tests and free-choice preference test procedures in C57BL6/J mice, as well as in mice lacking the ghrelin receptor (GHSR1a -/-) and their wild-type (WT) littermates.


RESULTS
In the single bottle tests, peripheral ghrelin consistently increased the consumption of saccharin, independently of availability of caloric food. In the free-choice preference test procedures, ghrelin increased the preference for saccharin in WT mice, while it did had not effect in GHSR1a -/-animals, indicating that the ghrelin receptor pathway is necessary to mediate this parameter.


CONCLUSIONS
Peripheral ghrelin enhances intake and preference for a sweet food, regardless of whether the food has caloric content. This effect, mediated through the ghrelin receptor pathway, may serve as additional enhancers of energy intake.
Laboratory of Metabolism, Division of Endocrinology, Diabetology and Nutrition, Department of Internal Medicine, Faculty of Medicine, University of Geneva, Geneva, Switzerland. emmanuel.disse@gmail.com
Emmanuel
E
Disse
Anne-Lise
AL
Bussier
Christelle
C
Veyrat-Durebex
Nicolas
N
Deblon
Paul T
PT
Pfluger
Matthias H
MH
Tschöp
Martine
M
Laville
Françoise
F
Rohner-Jeanrenaud
D000704:Analysis of Variance; D000818:Animals; D002755:Choice Behavior / Q000187:drug effects; D004435:Eating / Q000187:drug effects* / Q000235:genetics; D002149:Energy Intake / Q000187:drug effects* / Q000235:genetics; D005518:Food Preferences / Q000187:drug effects*; D054439:Ghrelin / Q000008:administration & dosage*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D054440:Receptors, Ghrelin / Q000172:deficiency; D012439:Saccharin / Q000008:administration & dosage / Q000494:pharmacology*; D013549:Sweetening Agents / Q000008:administration & dosage / Q000494:pharmacology*; D013649:Taste / Q000187:drug effects* / Q000235:genetics
D054439:Ghrelin; D054440:Receptors, Ghrelin; D013549:Sweetening Agents; D012439:Saccharin