We developed a methodology to measure plasma hepatic glutathione (GSH) turnover and we tested it in rats treated with an inhibitor of GSH synthesis. Our goal was to determine whether protein intakes above NRC recommendations maximize hepatic GSH stores and turnover in vivo. We also wished to learn if plasma GSH, cysteine, or methionine concentrations or plasma GSH turnover could be used as noninvasive predictors of liver GSH status. Rats were fed purified diets containing 0, 5, 10, 20 or 40% casein for one week. The 0 and 5% casein diets were considered inadequate in protein, 10% marginal, 20% adequate and 40% excessive. Liver GSH content (mmol/liver) of rats fed 0 and 5% casein diets was 12.29 $ pm$ 1.11 and 16.43 $ pm$ 0.95, respectively, and increased to 23.62 $ pm$ 1.82 in the 10% group. Liver GSH content did not differ between the 20 and 40% groups. As dietary casein increased from 0-20%, free plasma GSH and cysteine concentrations and plasma GSH turnover increased, but did not increase further with the 40% diet. A sigmoidal relationship between plasma GSH turnover and hepatic GSH content was demonstrated. The best predictor of liver GSH content was not free plasma GSH concentration nor plasma GSH turnover, but the free plasma cysteine concentration.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.59940 |
| Date | January 1991 |
| Creators | Hum, Susan |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (School of Dietetics and Human Nutrition.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001221792, proquestno: AAIMM67514, Theses scanned by UMI/ProQuest. |
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