Adaptive responses in hypothalamic neuropeptide Y in the face of prolonged high‐fat feeding in the rat

• DOI: 10.1046/j.1471-4159.2003.02217.x
• Publication Date: 2010-07-16T06:49:39Z
• Authors: Michelle J. Hansen; Valentina Jovanovska; Margaret J. Morris
• Keywords: 2. Zero hunger; Brain Chemistry; Male; 0301 basic medicine; Time Factors; Body Weight; Hypothalamus; Brain; Hyperphagia; Dietary Fats; Rats; Rats, Sprague-Dawley; Eating; Random Allocation; 03 medical and health sciences; Adipose Tissue; Animals; Neuropeptide Y; Injections, Intraventricular

Abstract While a dysregulation in neuropeptide Y (NPY) signaling has been described rodent models of obesity, few studies have investigated the time‐course changes NPY content and responsiveness during development diet‐induced obesity. Therefore we effect differing lengths (2–17 weeks) high‐fat diet on hypothalamic peptide content, release NPY‐induced hyperphagia. Male Sprague–Dawley rats (211 ± 3 g) were fed either (30% fat) or laboratory chow (5% fat). Animals implanted with intracerebroventricular cannulae to investigate feeding responses (0.5 nmol, 1 nmol) after 4 12 weeks diet. At earlier stage hyperphagia was not altered; however, animals maintained for longer duration hyper‐responsive NPY, compared chow‐fed control ( p < 0.05). Overall, tended be decreased from 9 17 Total negatively correlated plasma leptin concentration 0.05), suggesting system remains responsive leptin's inhibitory signal. In addition, overflow significantly reduced Together these results suggest reduction activity animals, perhaps an attempt restore energy balance.