Toxic Effects of Hyperbaric Conditions

Ultrastructure of the effect of T-514 obtained from Karwinskia humboldtiana on assembly and integrity of yeast's peroxisomes

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100084983 ◽

1991 ◽

Vol 49 ◽

pp. 136-137

Author(s):

J. Sepulveda-Saavedra ◽

I. Vander-Klei ◽

M. Venhuis ◽

Y. Piñeyro-Lopez

Keyword(s):

Culture Conditions ◽

Toxic Effects ◽

Candida Boidinii ◽

Central Mexico ◽

Poisonous Plant ◽

Biological Behaviour ◽

Enzyme Content ◽

Fat Deposits ◽

Yeast Model

Karwinskia humboldtiana is a poisonous plant that grows in semi desertic areas in north and central México. It produces several substances with different toxic effects. One of them designated T-514 damages severely the lung, kidney and liver, producing in the hepatoeyte large intracellular fat deposits and necrosis. Preliminary observations demonstrated that three is a decrease in the amount of peroxisomes in the hepatocytes of experimentally intoxicated rats and monkeys. To study the effect exerted by the T-514 on peroxisomes, a yeast model was selected, thus, three species: Saccha romices cerevisiae, Ilansenula polymorpha and Candida boidinii were used, because there is information concerning their peroxisome's morphology, enzyme content, biological behaviour under different culture conditions and biogenesis.

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Some Conditions Necessary for Pinocytosis

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100100457 ◽

1968 ◽

Vol 26 ◽

pp. 142-143

Author(s):

M. W. Brightman

Keyword(s):

Smooth Muscle ◽

Cell Membrane ◽

Toxic Effects ◽

Cytological Evidence ◽

Cell Processes

The cytological evidence for pinocytosis is the focal infolding of the cell membrane to form surface pits that eventually pinch off and move into the cytoplasm. This activity, which can be inhibited by oxidative and glycolytic poisons, is performed only by cell processes that are at least 300A wide. However, the interpretation of such toxic effects becomes equivocal if the membrane invaginations do not normally lead to the formation of migratory vesicles, as in some endothelia and in smooth muscle. The present study is an attempt to set forth some conditions under which pinocytosis, as distinct from the mere inclusion of material in surface invaginations, can take place.

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