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oai:www.ideals.illinois.edu:2142/21355 2023-07-10 col_2142_5131 col_2142_14781 com_2142_5130 com_2142_687 com_2142_397

Johnston, Patricia V. Bierer, Tiffany Linn 2011-05-07T13:06:16Z 2011-05-07T13:06:16Z 10000-01-01 1995 These studies utilized the preruminant calf animal model to compare the absorption, serum appearance and lipoprotein transport of several carotenoids commonly found in the human diet. In addition, this work examined the effect of fat level in meals on the absorption of $\beta$-carotene. The preruminant calf has been shown in previous studies to be an excellent model for human carotenoid absorption and metabolism. For this model, $\beta$-carotene was absorbed only through the lymphatic system and dietary fat was required for optimal $\beta$-carotene absorption. The fat level of subsequent meals following an initial $\beta$-carotene-containing meal was found to influence the total absorption of $\beta$-carotene from the initial meal suggesting the presence of a maximum carrying capacity for $\beta$-carotene transportation from the intestine from a single meal. Peak absorption of $\beta$-carotene in chylomicrons was found to occur simultaneously with cholesterol but was delayed several hours as compared to triglycerides. The preruminant calf was also shown to absorb a wide range of both polar and nonpolar carotenoids; the polarity of the carotenoid seemed to influence its transport in the blood and its residence time. The majority of serum carotenoids in the calf were found to be associated with the HDL lipoprotein fraction with the remainder being associated with the LDL fraction. The serum appearance of $\beta$-carotene following a dose of $\beta$-carotene in a water-soluble form was shown to be higher than that from the oil-soluble form of the carotenoid. When calves were fed $\beta$-carotene containing a high proportion of 9-cis $\beta$- carotene, no 9-cis $\beta$-carotene was detected in the serum suggesting the presence of a mechanism limiting the absorption and serum appearance of 9-cis $\beta$-carotene. Such a mechanism may be important in the regulation of the production of 9-cis retinoic acid. The results of these studies using the preruminant calf model agree with those results seen in human studies and provide new insight into the absorption and transport of various carotenoids commonly consumed by humans. Made available in DSpace on 2011-05-07T13:06:16Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9624288.pdf: 7048766 bytes, checksum: b4e7be9c19b2ed2de28dd20177883830 (MD5) Previous issue date: 1995 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:50:12Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:22:55-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9624288 (UMI)AAI9624288 http://hdl.handle.net/2142/21355 eng Copyright 1995 Bierer, Tiffany Linn Agriculture, Food Science and Technology Agriculture, Animal Culture and Nutrition Health Sciences, Nutrition Comparative absorption and transport of various carotenoids in the preruminant calf text Ph.D. Food Science and Human Nutrition Food Science and Human Nutrition University of Illinois at Urbana-Champaign Dissertation