Simultaneous effects of metabolic inhibitors on the viscosity, surface rigidity and cleavage in ilyanassa eggs

Butros, Joseph

doi:10.1002/jcp.1030470304

Cited by 9 publications

(2 citation statements)

References 17 publications

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“…There is, by evidence given here and previously (Butros 1956), an in dication that the viscosity or consistency of the cytoplasm is increased when the respiration of the eggs is suppressed. This change was found to be reversible and the eggs were found uninjured as shown by viscosity measure ments and fertilizability after washing.…”

Section: Discussionmentioning

confidence: 93%

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Cytoplasmic Viscosity in the Sea Urchin Egg During Suppressed Respiration

Butros

1958

CYTOLOGIA

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The centrifuge method of measuring protoplasmic viscosity in cells has been used repeatedly and depends upon the rate of stratification of pigment granules, yolk spheres and other formed particulates. The rate of stratifica tion is also an index of the consistency of cytoplasm and a measure of the degree of gelation of its colloids. Viscosity is influenced by a number of physical and chemical factors and its variation is related to physiological activities such as cyclosis, movement and cell division (Seifriz 1936, Heilbrunn 1952. Metabolites and metabolic inhibitors cause viscosity changes, naturally. Beams and Evans (1940) found colchicine to decrease the viscosity of Arbacia. Lithium chloride caused a rise of viscosity of myosin solution, while NaSCN had the reverse effect (Ranzi 1947). Although caffeine did not seem to effect viscosity of cytoplasm, it made the surface more rigid and resistant to deformation (Cheney 1949). Runnstrom and Kriszat (1950) found ATP to increase the viscosity of Psamrnechinus. High concentrations of monothiogly col caused an initial drop in the viscosity of gluten (alcoholic dispersion), followed by a gradual rise until a gel was formed which could be liquefied by urea (Pence and Olcott 1952).According to Loewy (1952) an actomyosin-like substance can be extract ed from the plasmodium of Physarum polycephalum that changes its viscosity in presence of ATP. A marked decrease followed by slow rise in viscosity was shown by the Ostwald viscosimeter.Pressure and temperature are factors in determining consistency of the protoplasm. Marsland (1950) using microscope-pressure chamber and pres sure-centrifuge equipment showed that significant changes in gelation resulted from temperature and pressure variations in Arbacia, due to alterations in the protein chains of the cortex. Landau et al (1954) subjected amoebae to 2550-3000 lb/in2 and found a decrease in pseudopodial size and move ment. With increased pressure, the amoebae lost the pseudopodia and rounded up and similar results were produced by lowered temperature. The same authors (1955) found ATP to have a strengthening effect upon the cortical gel of the sea urchin egg. Butros (1956) studied the effect of various respiratory inhibitors on cytoplasmic viscosity and surface rigidity in Ilyanassa eggs. Concentrations were selected that blockedd cleavage reversibly. Azide, iodoacetate and

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Section: Discussionmentioning

confidence: 93%

“…The same authors (1955) found ATP to have a strengthening effect upon the cortical gel of the sea urchin egg. Butros (1956) studied the effect of various respiratory inhibitors on cytoplasmic viscosity and surface rigidity in Ilyanassa eggs. Concentrations were selected that blockedd cleavage reversibly.…”

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confidence: 99%