María-Luisa Pita

Males and females gonad fatty acids of the sea urchins Paracentrotus lividus and Arbacia lixula (Echinodermata)

The aim of this study was to analyze male and female gonad fatty acids of two sea urchin species, Paracentrotus lividus and Arbacia lixula, from the south coast of Spain. Additionally, we investigated possible differences between two locations. The ovaries of both species showed higher percentages of 14:0, 16:0, 16:1n-7, 18:2n-6, 18:3n-3 and 18:4n-3 than testes and lower levels of 18:0, 22:1n-9, 20:4n-6 and 22:5n-3. In P. lividus but not in A. lixula, the level of 20:5n-3 was higher in testes than in ovaries. These differences between sexes probably indicate different requirements of males and females during gametogenesis although the presence of a large number of gametes in the mature gonad may also have influences on fatty acid composition. Significant differences in gonad fatty acid profiles where also found when individuals of P. lividus collected at a location of the Mediterranean region were compared with specimens collected at the Atlantic coast. The most remarkable changes were the lower levels of 14:0, 18:1n-7, 20:1n-9, 20:4n-6 and 22:4n-6 and the higher values of 20:1n-11, 20:5n-3 and 22:6n-3 found in males and females of the Mediterranean specimens compared to those of the Atlantic coast. These differences probably reflect the differences in potential food sources at each location.

The Effect of Seasonality on Gonad Fatty Acids of the Sea Urchins Paracentrotus lividus and Arbacia lixula (Echinodermata: Echinoidea)

ABSTRACT The sea urchins Paracentrotus lividus and Arbacia lixula were collected monthly for 1 y in the southern coast of Spain, and their gonad fatty acids were analyzed to evaluate seasonal variations. The gonad fatty acids of A. lixula significantly differed from those of P. lividus, probably because of substantial differences in diet. In both sea urchins, seasonal changes were mainly characterized by the marked decrease of the major polyunsaturated fatty acid 20:5n-3 in summer and early autumn, and the opposite increase of 20:1n-11, 18:1n-9 and the principal nonmethylene-interrupted diene 20:2&Dgr;5,11. Arachidonic acid showed the lowest levels in winter, increasing in April through May, and remaining at relatively high levels until the end of the year. Saturated fatty acids were less affected by seasonality, although they tended to decrease with advancing maturity of the gonad and to increase after spawning. These seasonal changes are discussed in relation to the annual reproductive cycle and to fluctuations in seawater temperature.

Serum and Urine Amino Acid Patterns during the First Month of Life in Small-for-Date Infants

Prenatal nutrition is impaired in small-for-gestational-age infants. Serum amino acids may show some biochemical features related to the nutritional state of these children. We have carried out a study on serum and urine amino acids in 12 small-for-date infants (SFD) and 14 healthy newborns from birth to 1 month of life. SFD infants showed a high serum level of alanine and decreased concentrations of branched chain amino acids, aspartate, cystine and tryptophan at birth. The results are compatible with a protein malnutrition state. Levels of serum amino acids in SFD infants showed no differences in relation to normal infants after 1 month of rehabilitation with a diet consisting of an adapted milk formula.

FATTY ACID COMPOSITION AND UTILIZATION IN DEVELOPING EGGS OF SOME MARINE NUDIBRANCHS (MOLLUSCA: GASTROPODA: OPISTOBRANCHIA) FROM SOUTHWEST SPAIN

Abstract The fatty acid composition of whole egg masses was investigated in 4 marine nudibranchs collected from the southwest of Spain: Polycera aurantiomarginata, Polycera quadrilineata, Berghia columbina and Berghia verrucicornis. The four species are carnivorous. All nudibranchs were characterized by high levels of n-3 polyunsaturated fatty acids (n-3 PUFA), mainly eicosapentaenoic acid (20:5n-3), docosapentaenoic acid (22:5n-3) and docosahexaenoic acid (22:6n-3). Other major fatty acids were the saturated palmitic (16:0) and stearic (18:0) acids, the monounsaturated oleic acid (18:1n-9) and the n-6 PUFA arachidonic (20:4n-6) and docosatetraenoic (22:4n-6) acids. Relative high percentages of the plasmalogen derivatives 16:0DMA and 18:0DMA were also detected. Univariate analysis showed that egg fatty acids from P. aurantiomarginata and P. quadrilineata significantly differed from those of B. columbina and B. verrucicornis. Higher levels of saturated fatty acids and 22:6n-3 and lower percentages of 18:0DMA, 22:4n-6 and 22:5n-3 were found in the spawns of both species of Polycera as compared with both of Berghia. Analysis of the bryozoon Bugula neritina and the sea anemone Sagartia troglodites, main preys of Polycera and Berghia respectively, showed that the differences observed in egg fatty acid composition were likely related to diet. Fatty acids of the fully developed embryos from P. aurantiomarginata and B. columbina, sampled immediately prior to hatching, were analyzed to investigate the dynamics of fatty acids during embryogenesis. The long chain PUFA 20:4n-6, 22:4n-6, 20:5n-3 and 22:5n-3 increased or remained stable during embryogenesis in both species whereas palmitoleic acid (16:1n-7) in B. columbina and 16:0, 17:0, 18:0 and 18:1n-9 in P. aurantiomarginata decreased. The major n-3 PUFA, 22:6n-3, marked decreased in B. columbina but remained unchanged in P. aurantiomarginata. These data indicate that fatty acids play different roles during embryogenesis and that in both nudibranchs the embryo requirements are not the same.

Involvement of glucocorticoids in the stimulation of rat kidney phosphoenolpyruvate carboxykinase activity after liver intoxication by carbon tetrachloride

The enhancement of rat kidney cortex phosphoenolpyruvate carboxykinase activity during acute liver intoxication by carbon tetrachloride (CCl4) did not appear to be related to metabolic acidosis. Blood glucocorticoids were higher in CCl4-treated animals than in controls. Adrenalectomy fully counteracted the stimulation of renal phosphoenolpyruvate carboxykinase activity and gluconeogenic capacity brought about by CCl4 administration. It is concluded that glucocorticoids are involved in the renal response to acute liver intoxication by CCl4.

Dissociation between renal gluconeogenesis and ammoniagenesis after acute liver intoxication

Renal glucose and ammonia production as well as phosphoenolpyruvate carboxykinase and phosphate-dependent glutaminase activities were measured for acute liver intoxication. Gluconeogenesis and phosphoenolpyruvate carboxykinase activity increased, whereas ammonia production and phosphate-dependent glutaminase showed no changes with respect to the controls. The dissociation between gluconeogenesis and ammoniagenesis may be explained by the differential effect on the enzymes in these conditions.