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S Ayala

Publications and source records attributed to S Ayala.

25 records · Page 2Linked to original sources
PubMed1975

[Effect of an essential fatty acids free diet on the lipidic composition of rat testicles (author's transl)].

The effect of a fat free diet on the fatty acid composition and histological changes of the testis of old rats was studied to investigate the possible function of docosa-4,7,10,13,16-pentaenoic acid in rat testicles. The lipidic composition, the fatty acid composition, the conversion of docosa-7,10,13,16-tetraenoic acid to arachidonic acid and the activity of the 6-desaturase were determined during the different periods in which the rats received a fat free diet. Comparatively, the changes in the fatty acid composition of the liver were also studied. Only the liver showed a change in the triglyceride content during the first month of treatment, and it regained its normal values afterwards. Both liver and testis changed the fatty acid composition. An increase of the acids of the oleic series and a decrease of the components of the linoleic series were shown. These changes were similar to the ones provoked by an essential fatty acid deficient diet on young animals. The amount of docosa-4,7,10,13,16-pentaenoic acid was very little changed. No significant change was shown either in the retroconversion of docosa-7,10,13,16-tetraenoic acid to arachidonic acid. However, the 6-desaturase activity of the testis was enhanced by the fat deficient diet. The possibility that arachidonic acid in the adult rat is mainly supplied by linoleic acid and not by the retroconversion of docosa-4,7,10,13,16-pentaenoic acid is discussed.

Animals↗
PubMed1975

[Effect of alloxan diabetes on the biosynthesis of unsaturated fatty acids from linoleic and arachidonic acids in rat liver and testis (author's transl)].

The effect of alloxan diabetes on the desaturating, elongating, and elongating-desaturating activity of the microsomes of rat liver and testis was studied. Linoleic and arachidonic acids were tested. It was found that in both liver and testis linoleic acid was desaturated to gamma-linolenic acid (18:3) when the conditions were exclusively desaturating. Diabetes deceased the 6-desaturase activity of both tissues. In elongating and desaturating conditions linoleic acid was converted to 18:3, 20:2, 20:3, 20:4, 22:2, 22:5 and 24:2 in both tissues. Alloxan diabetes decreased the activity of the reactions controlled by the 6-desaturase reducing the conversion to 18:3 in both tissues and to 20:4 only in liver. The elongating reactions were not significantly modified. When only elongating conditions were tested, either liver or testis synthetized only 20:2, 22:2 and 24:2 from linoleic acid and 22:4 from arachidonic acid. The elongating activity for both fatty acids was not decreased by diabetes. Therefore, it was proved that alloxan diabetes interferes with the metabolism of linoleic acid in both tissues, decreasing only the desaturation reaction, whereas the elongation of the fatty acid is not reduced.

Animals↗
PubMed1973

Fate of linoleic, arachidonic, and docosa-7,10,13,16-tetraenoic acids in rat testicles.

A comparative study was made on the fate of linoleic, arachidonic, and docosa-7,10,13,16-tetraenoic acids in various subcellular fractions of liver and testis from rats of different ages. It was demonstrated that testicular microsomes can desaturate and elongate linoleic and arachidonic acids in a manner similar to liver microsomes, and that testicular mitochondria can convert docosa-7,10,13,16-tetraenoic acid to arachidonic acid. Testicular or liver microsomes actively desaturate linoleic acid to gamma-linolenic acid and eicosa-8,11,14-trienoic acid to arachidonic acid. However, it was impossible to measure in vitro any direct conversion of adrenic acid (22:4 [n - 6]) to docosapentaenoic acid (22:5 [n - 6]) by either liver or testicular microsomes. Docosa-7,10,13,16-tetraenoic acid is incorporated preferentially into the triglyceride fraction of total testis, mitochondria, and microsomes, while linoleic and arachidonic acids are incorporated more into phospholipids. The capacity of testicular microsomes, but not of liver microsomes, to synthesize polyunsaturated fatty acids declines with age. It is proposed that the synthesis of acids of the linoleic family proceeds in two stages, a rapid one in which arachidonic acid is made and a second, slower, one in which C(22) and C(24) acids are synthesized. In addition, there appears to be a cycle between microsomes and mitochondria that acts to conserve essential polyunsaturated C(20) and C(22) fatty acids by means of synthesis and partial degradation, respectively. This cycle would restrict the loss of essential fatty acids and might be of importance for the supply of arachidonic acid in testis under specific requirements and especially in older animals.

Aging↗
PubMedDate not supplied

[Born with a cleft].

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Cleft Lip↗
PubMedDate not supplied

[Prone position: postural treatment for patients with adult respiratory distress syndrome. The nurse's point of view].

The prone position is a therapeutic strategy that can be beneficial in the treatment of adult respiratory distress syndrome (ARDS). In order to evaluate the advantages and possible complications associated with this postural change within the context of nursing, we analyzed retrospectively 71 turns carried out in 32 patients who met criteria for ARDS. The patient was turned by a team of 4 or 5 persons following a strict protocol. The PaO2/FIO2 ratio and SatO2 significantly increased in prone position, without any hemodynamic repercussions. No extubation or loss of vascular accesses or drainage tubes occurred. Complications included: facial edema, low-pressure lesions, and regurgitation of enteral nutrition.

Adult↗