Synthesis of protoporphyrin IX induced by 5-aminolevulinic acid in yeast cells in the presence of 2,2;-dipyridyl

5-Aminolevulinic acid (ALA), a precursor of porphyrin synthesis, increased the production of various porphyrin compounds in Candida guilliermondii cells. Metalloporphyrins and protoporphyrin IX (PPIX) were predominantly accumulated, respectively, at ALA concentrations of 0.2-0.4 mM and at those higher than 1.5 mM. 2,2;-Dipyridyl which complexed with bivalent metals significantly increased the content of endogenous PPIX even at ALA concentrations lower than 0.5 mM. Under these conditions, the yeast sensitivity to photodynamic effect of visible light (400-600 nm) dramatically increased due to photosensitization by endogenous PPIX.     

Identification of 17 alpha,20 alpha-dihydroxyprogesterone in testicular extracts after incubation with ketoconazole

The antifungal ketoconazole affects testosterone synthesis in dispersed rat testicular cells. In the presence of ketoconazole an accumulation of 17 alpha,20 alpha-dihydroxyprogesterone has been observed. This steroid was isolated from the testis of Wistar rats after a [4-14C]progesterone incorporation in the presence of ketoconazole. Its identification was achieved from the gas chromatographic/mass spectrometric analysis of the isolated radioactive fraction. A chemical derivatization of the fraction with butylboronic acid followed by mass spectrometric analysis confirmed the presence of 17 alpha,20 alpha-dihydroxyprogesterone.     

Correlation between the fatty acid composition and the activity of extracellular enzymes from Bacillus caldolyticus

Summary Bacillus caldolyticus, grown at 70°C, produces a highly active extracellular amylase and protease. Both enzymes are formed either within the membrane, or at its inner surface. The activity of both extracellular enzymes was found to decline drastically when brain-heart infusion was omitted from the medium. A simultaneous increase of both enzymes inside the cell was observed. The shifting in extra- and intra-cellular activity was caused by changes in membrane composition due to the increase of anteiso-odd and n-even, and the decrease of iso-odd fatty acids. Membrane composition and enzymic activity could be influenced by the addition of either leucine or iso-leucine as precursors for the synthesis of branched-chain fatty acids: In presence of leucine the anteiso-odd and n-even fatty acids returned to their normal level, while the iso-odd fatty acids increased. Simultaneously the extracellular protease activity increased, and the intracellular activity declined. Growth in amylose-medium supplied with leucine lead to a decrease of both the intra- and extracellular amylase, and changes in the fatty acid composition of the membrane which could not be restored by transfer of the organism to complete media. Addition of iso-leucine first lead to a sharp decrease of extracellular protease and a drastic increase of intracellular protease activity, accompanied by an increase of anteiso-odd and n-even fatty acids, and a decrease of iso-odd compounds. After the second growth in presence of iso-leucine the intra- and extra-cellular protease activity was reversed, and thus showed a return to the starting situation. The reversal is accompanied by the preferential incorporation of fatty acids with a higher melting point into the membrane. Extracellular amylase activity was found to increase after the first growth with iso-leucine, and to decline sharply after the second culture with iso-leucine, together with a very high intracellular amylase activity at that point. Extra- and intra-cellular amylase activity both declined upon growth in complete medium, while the fatty acid distribution remained different from the initial composition.     

Influence of Chilling on Electrolyte Permeability, Oxygen Uptake and 2,4-Binitrophenol Stimulated Oxygen Uptake in Leaf Discs of the Thermophilic Cucumis sativus

The effect of chilling was studied in leaf discs from the chilling-sensitive Cucumis sativus L. by measurement of the electrolyte leakage from the discs, by oxygen uptake and by uncoupling of respiration with 2,4 dinitrophenol. Short periods of chilling are characterized by minor significant increases of electrolyte permeability, of respiration and of preserved ability to be uncoupled by 2,4-dinilrophenol. A longer period of chilling resulted in a strongly increased electrolyte permeability, in reduced oxygen uptake and in disappearance of uncoupling by 2,4 dinitrophenol. In general the induced changes in permeability and respiration were reversible within 4 days of chilling, if the discs were placed at 25°C after chilling.     

Localisation histochimique de l'anhydrase carbonique dans l'oviducte de la poule

Résumé En employant la méthode histochimique de Hansson, l'anhydrase carbonique est recherché dans chaque segment de l'oviducte de jeunes poules et de poules adultes en ponte ou au repos. La réaction est contrôlée par l'acétazolamide.Chez toutes les poules l'activité dans l'épithélium est intense au niveau de l'infundibulum et diminue vite en direction du vagin. Cet anhydrase carbonique joue éventuellement un rôle dans le pH de l'oviducte.Les glandes fonctionnelles du magnum et de la partie proximale de l'isthme ne réagissent pas. Un très léger précipité est observé dans ces glandes involuées.L'activité de cette enzyme dans les glandes de la partie distale de l'isthme et de l'utérus varie selon l'état fonctionnel. En période de ponte un précipité net se manifeste après deux minutes d'incubation. En période de repos l'activité est faible mais reste toujours observable. Une comparaison de nos résultats avec ceux des morphologistes et des biochimistes nous permet de conclure que l'anhydrase carbonique de l'utérus et aussi de la partie distale de l'isthme joue un rôle important dans la formation de la coque calcaire.

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Carbonic anhydrase activity of the hen's oviduct

Summary The carbonic anhydrase activity is localized by the histochemical method of Hansson in the different parts of the oviduct of laying and not-laying hens, and in the oviduct of young hens. The specificity is controlled by acetazolamide.The carbonic anhydrase activity is high in the epithelium of the infundibulum of all the hens examined and it decreases towards the vagina. Its function is connected with the pH of the oviduct.The active glands of the magnum and the proximal part of the isthmus do not react. A small precipitation is observed in the inactive glands.The activity in the glands of the distal part of the isthmus and in the uterine glands depends to a high degree on the functional state. By laying hens the glands react after two minutes of incubation. By non-layers the activity is very diminished, but is still detectable. Comparing our results with those reported by other morphologists and biochemists, it can be concluded that the carbonic anhydrase of the uterus and also of the distal part of the isthmus is very important for the egg-shell formation.