Hepatic â-oxidation and liver and skeletal muscle carnitine palmitoyltransferase I (CPT I) activity and mRNA expression were evaluated in the pig. In the first study, newborn pigs were allotted to one of four dietary regimens: artificial milk replacer with long chain triglycerides (LCT) as the fat source (Control), the Control diet with 0.5% clofibric acid (CA), the Control diet with medium chain triglycerides replacing LCT as the fat source (MCT), or the Control diet with 40 ppm isoproterenol (ISO). There were no differences between Control and MCT or ISO supplemented groups in total, mitochondrial, or peroxisomal â-oxidation of [1-<sup>14</sup>C]-palmitate (1 mM). Total and peroxisomal â-oxidation increased 134 and 186%, respectively, with CA supplementation. Hepatic malonyl-CoA sensitive CPT activity increased (p < 0.05) in pigs receiving CA. Changes in relative expression of hepatic LCPT I and skeletal muscle MCPT I mRNA amounts following clofibrate supplementation were not detected, while a modest effect on acyl-CoA oxidase (ACO) relative mRNA amounts was observed (p=0.08). In the second study, hepatic and skeletal muscle CPT I kinetics in pigs during different stages of development were evaluated. Activity of CPT I increased 109 and 67% between birth and 1 wk of age in liver and skeletal muscle, respectively (p < 0.05). Realtive expression of hepatic CPT I mRNA in the 24 hr old pig was 7% of the amount detected in the newborn (p < 0.001); while hepatic CPT I apparent Km for carnitine decreased 48% from birth to 3 wk of age. The apparent Km for carnitine in skeletal muscle decreased from birth to 1 wk of age, then increased 200% between 1 and 5 wk of age (p< 0.01). Plasma and liver free carnitine concentrations increased 200 and 160%, respectively, during the first day of life (p < 0.05). High relative expression of ã-butyrobetaine hydroxylase (ãBBH) in the kidney indicated high capacity for de novo carnitine synthesis by this tissue. Collectively, the findings from this research are important in understanding how the pig, a species with a low capacity for â-oxidation, utilizes fatty acids.
| Identifer | oai:union.ndltd.org:NCSU/oai:NCSU:etd-09142004-195837 |
| Date | 20 September 2004 |
| Creators | Lyvers Peffer, Pasha A |
| Contributors | Dr. William Miller, Dr. Jack Odle, Dr, Joan Eisemann, Dr. Robert Harrell |
| Publisher | NCSU |
| Source Sets | North Carolina State University |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://www.lib.ncsu.edu/theses/available/etd-09142004-195837/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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