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Stearoyl-ACP desaturases (SADs) and fatty acid desaturases (FADs) play a critical role in plant lipid metabolism and also affect oil fatty acid composition introducing double bonds into the hydrocarbon chains to produce unsaturated fatty acids. In the present study, the genomic sequences of three SAD and three FAD candidate genes were characterized in olive and their expression was evaluated in different plant tissues. OeSAD genes corresponded to olive SAD1 and SAD2 and to a newly identified OeSAD4, sharing the conserved protein structure with other plant species. On the other hand, the full-length genomic sequences of two microsomal OeFAD genes (FAD2-1 and FAD2-2) and the plastidial FAD6, were released. When the level of expression was tested on different tissues of cv. Leccino, OeSAD1 and OeSAD2 were mainly expressed in the fruits, while OeFAD genes showed the lowest expression in this tissue. The mRNA profiling of all genes was directly studied in fruits of Leccino and Coratina cultivars during fruit development. In both genotypes, the expression level of OeSAD1 and OeSAD2 had the highest value during and after the pit-hardening period, when oil accumulation in fruit mesocarp is intensively increasing. Furthermore, the expression level of both OeFAD2 genes, which were the main candidates for oleic acid desaturation, were almost negligible during fruit ripening. These results have made possible to define candidate genes of the machinery regulation of fatty acid composition in olive oil, providing information on their sequence, gene structure and chromosomal location.

The importance of the glutathione (GSH) redox cycle and of catalase as intracellular antioxidant defense systems in cultured endothelial cells against an extracellular flux of H2O2, a critical mediator of polymorphonuclear leukocyte-induced oxidant injury of endothelial cells, was examined. The activities of different parts of the GSH redox cycle were impaired by 1,3-bis(2-chloroethyl)-1-nitrosourea, buthionine sulfoximine, diethyl maleate and 2-cyclohexene-1-one. Catalase activity was inhibited by 3-amino-1,2,4-triazole. After an impairment of the GSH redox cycle, but not of catalase, the susceptibility of pulmonary artery endothelial cells to an attack by H2O2 was dramatically increased independent of the source of extracellularly generated hydrogen peroxide (i.e., glucose oxidase or stimulated polymorphonuclear leukocytes). Exogenous catalase, d-alpha-tocopherol, and particularly Trolox, the chroman compound of tocopherol, but not phytol, the fatty acid side chain of tocopherol, provided almost complete protection of the endothelial cells against a H2O2-mediated attack. Additional fluorometric studies suggested that H2O2 is scavenged by the antioxidants before it hits the target cells.

Es wurde in Ratten- und Schweineleber ein Enzymsystem gefunden, das Cortison in Compound F umwandelt. Dieses Enzymsystem ist an die geformten Zellbestandteile gebunden, vorwiegend an die Mikrosomen. Die Untersuchungen vonKahnt undWettstein uber die Umwandlung vonReichsteins Compound S inKendalls Compound F konnten mit Rattenleber bestatigt werden.

Zusatz von osmotisch cytolysiertenmyeloischen Zellen aus Leukamikerblutverlangert die Recalcifizierungszeit und die nach der einzeitigen Methode gemessene Prothrombinzeit von Normalplasma. Zusatz von cytolysiertenLymphocyten aus dem Blut chronischer Lymphadenosenverkurzt die Recalcifizierungszeit und die Prothrombinzeit. Die Leukocyten aus Normalblut verkurzen die Prothrombinzeit bis zu einer Konzentration von rund 5000000 je Ansatz und verlangern in hoheren Konzentrationen. Reife eosinophile Zellen verhalten sich wie Leukocyten aus Normalblut. Aus diesen Versuchen scheint hervorzugehen, das die Leukocyten einen Einflus auf die Gerinnungsmechanismen des Blutes haben, wobeimyeloische Zellen eine gerinnungs-verzogernde, dielymphatischen Zellen eine gerinnungs-fordernde Wirkung erkennen lassen.