Sex‐dependent regulation of hypothalamic neuropeptide Y‐Y1 receptor gene expression in moderate/high fat, high‐energy diet‐fed mice

F Zammaretti, G Panzica, C Eva - The Journal of Physiology, 2007 - Wiley Online Library
F Zammaretti, G Panzica, C Eva
The Journal of Physiology, 2007Wiley Online Library
In this study we investigated whether long‐term consumption of a moderate/high fat (MHF),
high‐energy diet can affect the gene expression of the Y1 receptor (Y1R) for neuropeptide Y
(NPY) in the dorsomedial (DMH), ventromedial (VMH), arcuate (ARC) and paraventricular
(PVN) hypothalamic nuclei of male and female Y1R/LacZ transgenic mice, carrying the
murine Y1R promoter linked to the LacZ gene. MHF diet‐fed male mice showed an
increased consumption of metabolizable energy that was associated with a significant …
In this study we investigated whether long‐term consumption of a moderate/high fat (MHF), high‐energy diet can affect the gene expression of the Y1 receptor (Y1R) for neuropeptide Y (NPY) in the dorsomedial (DMH), ventromedial (VMH), arcuate (ARC) and paraventricular (PVN) hypothalamic nuclei of male and female Y1R/LacZ transgenic mice, carrying the murine Y1R promoter linked to the LacZ gene. MHF diet‐fed male mice showed an increased consumption of metabolizable energy that was associated with a significant increase in body weight as compared with chow‐fed controls. In parallel, consumption of a MHF diet for 8 weeks significantly decreased Y1R/LacZ transgene expression in the DMH and VMH of male mice whereas no changes were found in the ARC and PVN. Leptin treatment reduced body weight of both MHF diet‐ and chow‐fed male mice but failed to prevent the decrease in Y1R/LacZ transgene expression apparent in the DMH and VMH of male mice after 8 weeks of MHF diet intake. Conversely, no significant changes of metabolizable energy intake, body weight or hypothalamic β‐galactosidase expression were found in MHF diet‐fed female Y1R/LacZ transgenic mice. A gender‐related difference of Y1R/LacZ transgenic mice was also observed in response to leptin treatment that failed to decrease body weight of both MHF diet‐ and chow‐fed female mice. Results herein demonstrate that Y1R/LacZ FVB mice show a sexual dimorphism both on energy intake and on nucleus‐specific regulation of the NPY Y1R system in the hypothalamus. Overall, these results provide new insights into the mechanism by which diet composition affects the hypothalamic circuit that controls energy homeostasis.
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