Record Details
Field | Value |
---|---|
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 |