Body weight loss, effective satiation and absence of homeostatic neuropeptide compensation in male Sprague Dawley rats schedule fed a protein crosslinked diet

Abstract

Food structure contributes to the induction of satiation and the maintenance of satiety following intake of a meal. There is evidence from human studies that protein-crosslinking of a milk-protein based meal may enhance satiety, but the mechanism underpinning this effect is unknown. We investigated whether a rat model would respond in a similar manner and might provide mechanistic insight into enhanced satiety by structural modification of a food source. Rats were schedule fed a modified AIN-93M based diet in a liquid form or protein-crosslinked to produce a soft-solid form. This was compared to a modified AIN-93M solid diet. Average daily caloric intake was in the order solid > liquid > crosslinked. Body composition was unaltered in the solid group, but there was a loss of fat in the liquid group and a loss of lean and fat tissue in the crosslinked group. Compared to rats fed a solid diet, acute responses in circulating GLP-1, leptin and insulin were eliminated or attenuated in rats fed a liquid or crosslinked diet. Quantification of homeostatic neuropeptide expression in the hypothalamus showed elevated levels of Npy and Agrp in rats fed the liquid diet. Measurement of food intake after a scheduled meal indicated that reduced energy intake of liquid and crosslinked diets is not due to enhancement of satiety. When continuously available ad-libitum, rats fed a liquid diet showed reduced weight gain despite greater 24 h caloric intake. During the dark phase, caloric intake was reduced, but compensated for during the light phase. We conclude that structural modification from a liquid to a solidified state is beneficial for satiation, with less of a detrimental effect on metabolic parameters and homeostatic neuropeptides.

Potensi Hibiscus sabdariffa Linn. Memodulasi GLP-1 dan Neuropeptide Y (NPY) di Nucleus Arcuatus pada Tikus Obes

“…dapat meningkatkan kadar hormon GLP-1 di perifer. 16,[22][23][24] Untuk dapat menjelaskan peran Hibiscus sabdariffa Linn. dalam sintesis GLP-1 di sentral, maka perlu dilakukan penelitian lebih lanjut dengan mengukur beberapa parameter seperti: kadar GLP-1 dalam darah dan dalam NTS, mengukur kadar leptin dalam darah, mengukur ekspresi mRNA reseptor GLP-1 dan NPY di Nucleus Arcuatus (ARC).…”

Roles of Neuropeptide Y in Neurodegenerative and Neuroimmune Diseases

“…In summary, NPY modulates neurogenesis and neurotrophins, increases trophic support, decreases excitotoxicity, regulates calcium homeostasis, and attenuates neuroinflammation. Additionally, NPY also influences the common clinical manifestations of neurodegenerative diseases, such as depression and weight change (Cassie et al, 2017; Brown et al, 2018). Alterations in neurogenesis and neurotrophic factor expression or neuroinflammation, impairments in the serotonergic and noradrenergic systems, and hypothalamic-pituitary-adrenal (HPA) axis dysfunction, all contribute to the depressive symptoms of neurodegenerative disorders (Ayuob et al, 2018).…”