Record Details

Carnitine and derivatives in embryonic chick tissues

ScholarsArchive at Oregon State University

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Title Carnitine and derivatives in embryonic chick tissues
Names Casillas, Edmund Rene (creator)
Newburgh, Robert W. (advisor)
Date Issued 1968-12-16 (iso8601)
Note Graduation date: 1969
Abstract Carnitine, acetylcarnitine, and long-chain acylcarnitine concentrations
were determined for heart, brain, and liver of chick
embryos during various stages of development. The total carnitine
concentration was approximately the same in all three organs and
showed only small variations during development. Acetylcarnitine
was not detected in any organ until the seventeenth day of incubation
and represented about 20% of the total carnitine on the day of hatch,
in each organ. Long-chain acylcarnitine concentrations generally
represented from five to ten percent of the total carnitine in each
case. In the heart, the carnitine used for the synthesis of acetylcarnitine
appeared to come from long-chain acylcarnitine. In the
brain and liver, this carnitine apparently was derived from free
carnitine.
Levels of carnitine acetyltransferase activity were measured in
hearts, brains, livers and yolk sacs of chick embryos at various
stages of development. The levels of activity of this enzyme corresponded
to the increase in acetylcarnitine concentrations with
development in the heart and liver. Only very low levels of transferase
activity were detected in the brain. The increase in acetylcarnitine
concentration and the parallel increase in carnitine acetyltransferase
activity in organs correlated with the increase of fatty
acid oxidation in the embryo during the last week of development.
The relatively high level of carnitine acetyltransferase activity in the
yolk sac appeared to be localized in the yolk sac-membrane. The
possibility that this yolk sac-enzyme may function in the transfer of
fatty acyl groups from the yolk into the embryo is presented.
Perchloric acid extracts of chick embryonic tissues contained
a substance which interferes with the assays for carnitine and acetylcarnitine.
The interference was attributed to an inhibitor of the
carnitine acetyltransferase reaction used in the assays. The low
molecular weight inhibitor was not a protein and was heat stable,
soluble in aqueous solvents but insoluble in chloroform-methanol.
In addition, the inhibitory phenomenon appeared to be enhanced by
treatment with dilute base. By careful adjustment of the tissue
extract concentration in the assay mixture, carnitine and acetylcarnitine
were accurately determined in the presence of the inhibitor.
Genre Thesis/Dissertation
Topic Embryology -- Birds
Identifier http://hdl.handle.net/1957/46844

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