2026-09-20T20:17:59Zhttps://digital.library.adelaide.edu.au/server/oai/request

oai:digital.library.adelaide.edu.au:2440/581952016-06-26T04:15:58Zcom_2440_14759col_2440_14760

Symonds, Erin Leigh School of Psychology 2002 http://hdl.handle.net/2440/58195 Assessment of gastric emptying in animals is hampered by the lack of a technique that is noninvasive and does not involve sacrificing the animal. The primary aims of these studies therefore were to develop the breath test for the mouse and then investigate gastric emptying rates in physiological, pathological and pharmacological studies. After an overnight fast, mice were fed a solid or liquid meal that contained a ¹³C-labelled substrate, and placed in breath collection chambers. Breath samples collected at intervals were analysed for levels of ¹³C0₂, with the rate of appearance in the breath giving a measure of the gastric emptying rate. The breath testing technique was shown to be reproducible and sensitive enough to be able to detect induced alterations to gastric emptying, with results comparable to those obtained from other techniques. The breath test was used to assess gastric emptying in mice and showed that: (1) H. pylori infection accelerated gastric emptying in the initial weeks of infection, whilst a more severe stomach inflammation caused dysmotility; (2) baclofen (a potential reflux therapy) accelerated gastric emptying of solids and delayed liquid emptying in a dosedependent manner; and (3) mice with a high daily food intake had faster emptying compared to those with low intake, which resulted in the same weight gain of the two groups. Breath testing was also used in adults and children and showed that: (1) increasing the caloric content of a solid meal delayed the emptying of the solid, but not of a liquid given simultaneously; (2) gastric emptying rate is correlated to the amount of colonic gas produced; and (3) improvement in pancreatic lipase activity with pancreatic enzyme replacement is inversely related to the gastric emptying time. Breath testing was also used to show that substrates with a natural ¹³C-enrichment can be used to assess small intestinal enzyme activity. Breath testing is a sensitive and reproducible tool to investigate gastric emptying in mice. Its noninvasive nature allows it to be repeated within each subject which is useful for follow-up investigations. It can now be applied further to a range of disease, pharmacological and nutritional investigations. Thesis (Ph.D.) -- University of Adelaide, Dept. of Physiology, 2002 gastrointestinal function; breath testing Non-invasive assessment of gastrointestinal function using breath test technology : investigations in health and disease. Thesis This electronic version is made publicly available by the University of Adelaide in accordance with its open access policy for student theses. Copyright in this thesis remains with the author. This thesis may incorporate third party material which has been used by the author pursuant to Fair Dealing exception. If you are the author of this thesis and do not wish it to be made publicly available or If you are the owner of any included third party copyright material you wish to be removed from this electronic version, please complete the take down form located at: http://www.adelaide.edu.au/legalsopen.access