Identifier

etd-07092008-100712

Degree

Master of Science (MS)

Department

Human Ecology

Document Type

Thesis

Abstract

Resistant starch (RS) is fermentable dietary fiber. It has been shown that inclusion of resistant starch in the diet causes decreased body fat accumulation and altered gut hormone profile. Gut hormone has complex effect on neuropeptides’ expression in the brain hypothalamic area which is regarded as key factors in regulation of energy homeostasis. In this project, thereby, it is proposed that 1) the hypothalamic neuropeptide Y (NPY), agouti-related peptide (AgRP) and pro-opiomelanocortin (POMC) mRNA expression may be altered by RS feeding; 2) afferent vagal nerves might be involved in this process. Animal experiment was conducted to investigate the hypothesis. The rats were injected intraperitoneally with capsaicin to destroy unmyelinated small vagal afferent nerve fibers. The cholecystokinin food suppression test was performed to validate the effectiveness of the capsaicin treatment. Then, capsaicin treated rats and vehicle treated rats were subdivided into a control diet or a resistant starch diet group, and fed the corresponding diet for 65 days. At the end of study, body fat, food intake, plasma peptide YY (PYY) and glucagon-like peptide -1 (GLP-1), and hypothalamic pro-opiomelanocortin, neuropeptide Y, agouti-related peptide gene expressions were measured. Resistant starch fed rats had decreased body fat, increased POMC expression in the hypothalamic arcuate nucleus, and elevated plasma PYY and GLP-1 in both the capsaicin and vehicle treated rats. Hypothalamic NPY, AgRP gene expressions and food intake were not changed by resistant starch or capsaicin. Therefore, destruction of the capsaicin sensitive afferent nerves did not alter the response to resistant starch in rats. The conclusion is that dietary resistant starch might reduce body fat through increasing the hypothalamic POMC expression and vagal afferent nerves are not involved in this process.

Date

2008

Document Availability at the Time of Submission

Release the entire work immediately for access worldwide.

Committee Chair

Roy J Martin

Included in

Human Ecology Commons

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