1. Acetylcarnitine added in catalytic amounts to kidney mitochondria produces an active oxidation of endogenous fatty acids. 2. In conditions of mitochondrial ;aging', under which acetate is not oxidized, acetylcarnitine also promotes the oxidation of this exogenous substrate. 3. Dinitrophenol completely abolishes the action of acetylcarnitine. 4. Carnitine is ineffective both in the oxidation of endogenous fatty acids and of exogenous acetate. 5. The action of acetylcarnitine is shared, though to a smaller extent, by pyruvate. 6. The mechanism of acetylcarnitine action has been interpreted by considering that the readily oxidizable acetyl group of acetylcarnitine can supply the initial investment of energy needed to start fatty acid oxidation.

Acetates↗

PubMed1964

[Reversible enzymatic transfer of coenzyme A from succinyl-S-Co A to acetate by the action of respiratory particles of yeast].

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Acetates↗

PubMedDate not supplied

L-propionyl-carnitine protection of mitochondria in ischemic rat hearts.

The energy-linked processes (transmembrane potential and oxidative phosphorylation) resulted in impaired mitochondria isolated from ischemic perfused rat hearts. Addition of 1.5 mM L-propionyl-carnitine to the perfusate significantly reduced the ischemic damage and ameliorated mitochondrial Ca2+ homeostasis. In both normoxic and ischemic hearts perfused with L-propionyl-carnitine a consistent amount of propionyl-CoA-otherwise undetectable-was produced. L-propionyl-carnitine treatment also prevented the decrease of succinyl-CoA associated with the ischemic condition. These results and the decrease of myocardial acetyl-CoA induced by exogenous L-propionyl-carnitine points to the anaplerotic effect of this ester. The consequently improved flux in the tricarboxylic-acid cycle may account for the observed protection of mitochondrial functions afforded by L-propionyl-carnitine in the ischemic perfused hearts.

Acyl Coenzyme A↗

PubMedDate not supplied

[Obstetric/neonatological integration and care of healthy newborn infants].

We report how we changed the model of the organization and the assistance in our Department of healthy newborns (2200-2400/years). After we have realized that mothers were not satisfied of the rules of the hospital and personnel was not satisfied of the job, we decided to begin a process of analysis and review of the procedures on full term newborn. During this process we found out that the most important thing was to have clear in mind the problems and the needs of the mother and the baby, and not those of nurses and doctors. A similar process took place in the Department of Obstetrics. In this way we, Obstetrics and Neonatologist together, began to offer a more human approach to birth, and rooming-in began. We stopped to attend every normal delivery, to separate immediately mother and baby, to feed the baby at fixed time, to give him supplementations. We tried to have with the mother a better relationship, visiting the baby in presence of the mother an receiving grom Obstetrics as soon as possible every information about pregnancy. We realized that this was possible only if the Neonatologist and the Obstetric were of the same opinion about a more human approach to birth. We stress this point, well aware that it's impossible to reach this goal unless everybody in any way involved in birth work in great harmony with all the others. A further result of this "new" way of working has been the program of early discharge: if desired, and whenever possible, the mother and the baby go home 48-72 hours after delivery. We report here preliminary data.

Adult↗

PubMedDate not supplied

[Significance of evening primrose oil in the problem of the nutritional value of poly-unsaturated fatty acids].

The essential nutritional value of the polyunsaturated fatty acids can, in the light of present-day knowledge, be considered valid in all respects as regards the n-6 family which derives from linoleic acid. On the other hand, the polyunsaturated fatty acids of the n-3 family deriving from linolenic acid to not possess essential requisites as, for instance, they are ineffective for healing skin lesions caused by deficiency of polyunsaturated fatty acids. Unsaturated fatty acids taken in with the diet have a two-fold function: 1) plastic, insofar as they are necessary for the biosynthesis of the phospholipids; 2) regulatory, as precursors of prostanoids or eicosanoids (prostaglandins, thromboxanes, prostacyclins). The process of desaturation-lengthening that leads to the formation of these compounds is, however, limited by the activity of desaturase, which is in poor enough supply, especially in certain tissues, under physiological conditions and is almost non-existent in certain pathologies such as diabetes, alcoholism, anaemia and hypercholesterolaemia. The recent use of vegetable oils such as those obtained from the seeds of Evening Primrose, is of particular interest owing to the presence of gamma-linolenic acid, the product of the activity of desaturase. In the light of this unusual property, the recent nutritional-therapeutic results obtained by using this vegetable oil are described.

Fatty Acid Desaturases↗

PubMedDate not supplied

Carnitine transport in rat heart slices: I. The action of thiol reagents on the acetylcarnitine/carnitine exchange.

Rat heart slices show a permeability barrier that can be crossed by carnitine but not by sucrose and inulin. The integrity of thiol groups of heart cell membrane is essential for the uptake of carnitine. N-ethylmaleimide inhibits the transport into heart slices which is insensitive to Mersalyl. On the contrary both N-ethylmaleimide and Mersalyl inhibit acetyl carnitine/carnitine exchange. The amount of thiol groups titrated by the above reagents are related to the extent of exchange inhibition.

Acetylcarnitine↗

PubMedDate not supplied

Carnitine transport in rat heart slices: II. The carnitine/deoxycarnitine antiport.

In rat heart slices carnitine transport occurs in an exchange process with deoxycarnitine. This has been demonstrated in double labelling experiments allowing a preloading of either 3H-carnitine or 14C-deoxycarnitine, the immediated precursor of carnitine. The stoichiometry of the carnitine/deoxycarnitine exchange resulted close to one in both directions. The relative kinetics supports the assumption that the process is mediated by a membrane bound protein. The results may rationalize the circumstance that carnitine is taken up by myocardium against a concentration gradient. The meaning of the carnitine/deoxycarnitine exchange is discussed.

Animals↗

PubMedDate not supplied

[Center for the Study of Physiology of Mitochondria, Padua].

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Adenine Nucleotides↗