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.
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.
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.