Thioctic Acid Content and Pyruvate Oxidation in Ethionine-Damaged Rat Livers.

Cyanobacteria are Gram negative prokaryotes that are capable of oxygenic photosynthesis. Although there are many similarities between eukaryotes and cyanobacteria in electron transfer and phosphorylation during photosynthesis, there are two features of the photosynthetic apparatus in cyanobacteria which distinguishes them from plants. Cyanobacteria contain phycobiliproteins organized in phycobilisomes on the surface of photosynthetic membrane. Another difference is in the organization of the photosynthetic membranes. Instead of stacked thylakolds within a chloroplast envelope membrane, as seen In eukaryotes, IntracytopIasmlc membranes generally are arranged in three to six concentric layers. Environmental factors such as temperature, nutrition and light fluency can significantly affect the physiology and morphology of cells. The effect of light Intensity shifts on the ultrastructure of Internal membrane in Anabaena variabilis grown under controlled environmental conditions was examined. Since a major constituent of cyanobacterial thylakolds are lipids, the fatty acid content also was measured and correlated with uItrastructural changes. The regulation of fatty acid synthesis in cyanobacteria ultimately can be studied if the fatty acid content can be manipulated.

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Ultrastructural changes in isolated rat liver perfused with cyclic heptapeptide toxins from norwegian freshwater cyanobacteria (blue-green algae)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100128572 ◽

1987 ◽

Vol 45 ◽

pp. 858-859

Author(s):

A.S. Dabholkar ◽

W.W. Carmichael ◽

K. Berg ◽

J. Wyman

Keyword(s):

Ultrastructural Changes ◽

Sprague Dawley ◽

Isolated Rat Liver ◽

Blue Green Algae ◽

Sprague Dawley Rats ◽

Cyclic Heptapeptide ◽

Intracellular Changes ◽

Oscillatoria Agardhii ◽

Rat Livers ◽

Isolated Rat

Intracellular changes in the hepatocytes of isolated rat livers perfused with cyclic heptapeptide toxins are described. The toxins used are 1) -Ala-Leu- β-methyl isoAsp-Arg-ADDA-isoGlu-mdha (M.W. 944) from Microcystis aeruginosa- Lake Akersvatn, Norway; 2) -Ala-Arg-isoAsp-Arg-ADDA-isoGlu-mdha (M.W. 1023) from Oscillatoria agardhii var. - Lake Kolbatnvatn, Norway; 3) -Ala-Arg-isoAsp-Arg-ADDA-isoGlu-dha (M.W. 1009) from Oscillatoria agardhii var. isothrix - Lake Froylandsvatn, Norway. Approximate LD intraperitoneal mouse for the toxins is 50, 500 and 1000 μg/kg respectively.Livers were removed from male Sprague Dawley rats and perfused for 15 min with a blood-free perfusate (50 ml) followed by 60 min with perfusate containing i) 25, 50, or 200 μg of M. aeruginosa toxin ii) 50, 250, 500 or 1000 μg of O. agardhii var. toxin and iii) 1000, 2000, 2500 or 5000 μg of O. agardhii var. isothrix toxin. Control livers were perfused for 75 min with the blood-free perfusate.

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