Studies on the Hydrogen-Ion Concentration of Insect Blood and Their Bearing on in vitro Cytological Technique

Boche, R; Buck, John D.

doi:10.1086/physzool.15.3.30151642

Cited by 18 publications

(3 citation statements)

References 21 publications

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“…NaOH to bring pH to 7.40 (about 5 mM). This medium was formulated to approximate Chironornus larval hemolymph in respect to reported content of chloride and cations (Bond and Koch, 1942;Duch~teau et al, 1953), osmolarity (Harnisch, 1934, 1943, and pH (Boche and Buck, 1942). The choice of anions besides chloride was guided by the reported prominence of organic acids of the tricarboxylic acid cycle in the hemolymphs of other endopterygote larvae (Wyatt, 1961 ;Florkin and Jeuniaux, 1964), and glutamine was used to fill the osmotic deficit because of its abundance in these hemolymphs (Florkin and Jeuniaux, 1964).…”

Section: Mediamentioning

confidence: 99%

Permeability of a Cell Membrane Junction

Politoff

Socolar

Loewenstein

1969

The Journal of General Physiology

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The ion permeability of the membrane junctions between Chironomus salivary gland cells is strongly depressed by treatments that are generally known to inhibit energy metabolism. These treatments include prolonged coolhag at 6°-8°C, and exposure to dinitrophenol, cyanide, oligomycin, and Nethylmaleimide. IntraceUular injection of ATP appears to prevent depression of junctional permeability by dinitrophenol or to reverse it. Ouabain, azide, pchloromercuriphenylsulfonic acid, reserpine, and acetazolamide fail to depress junctional permeability. Thus the ion permeability of the junctional membranes appears to depend on energy provided by oxidative phosphorylation. Possible energy-linked processes for maintaining junctional permeability are discussed, including processes involving transport of permeability-modifying species such as Ca ++ .

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Section: Mediamentioning

confidence: 99%

Permeability of a Cell Membrane Junction

Politoff

Socolar

Loewenstein

1969

The Journal of General Physiology

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“…This explains the observations of cytologists who found that the visibility of chromosomes changes with pH, tonicity of the medium, mechanical injury, etc. (8,12,36). In telophase, together with the despiralization, the chromosomes extend again, so that they all touch each other and can no longer be seen individually.…”

Section: Discussionmentioning

confidence: 99%

The State of the Chromosomes in the Interphase Nucleus

Ris

Mirsky

1949

Journal of General Physiology

121

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In the living interphase nucleus no chromosomal structures are visible. Yet in the injured cell and after treatment with most histological fixatives chromatin structures become apparent. Under certain conditions this appearance of structure in the living interphase nucleus is reversible. We have found that this change in the interphase nucleus is the result of a change in the state of the chromosomes. In the living nucleus the chromosomes are in a greatly extended state, filling the entire nucleus. Upon injury the chromosomes condense and therefore become visible. At the same time the nuclear volume decreases. This behavior of the chromosomes is connected with their content of desoxyribonucleic acid (DNA). This view is based on the following observations: (a) Distribution of DNA in the Nucleus.—(1) The living interphase nucleus of uninjured cells absorbs diffusely at 2537 Å. No chromosomal structures are visible in ultraviolet photographs unless they are also distinct in ordinary light. If the chromosomes are made to condense they become visible and the absorption at 2537 Å is now localized in these structures. (2) After fixation with formalin and osmic acid interphase nuclei stain diffusely with Feulgen. These fixatives preserve the extended state of the chromosomes. (3) If nuclei are teased out in non-electrolytes (sucrose, glycerin) the chromosomes are extended. Such nuclei stain homogeneously with methyl green. On adding salts the chromosomes condense and the methyl green is now restricted to the visible structures. (b) Extension and Condensation of Isolated Chromosomes.—When chromosomes isolated from interphase nuclei of calf thymus are suspended in sucrose, their volume is four to five times larger than in saline, but they retain their characteristic shapes. Chromosomes from which DNA and histone have been removed do not show this reversible extension and condensation, neither do lampbrush chromosomes of frog oocytes which contain very little DNA. During mitosis a partial condensation of the DNA occurs in prophase, so that the mitotic chromosomes now occupy a much smaller volume of the nucleus. At telophase the chromosomes swell again to fill the entire nucleus.

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“…the blood plasma of ACRIDIDAE remain almost unstudied. Its reaction was found to be mostly weakly acid in a number of North American species, the average pH values being 6.3-6-9, but there was a considerable variation not only between species (from 6.0 to 7.6) but also between different determinations in the same species (Boche and Buck 1942 ;Hastings and Pepper 1943). Russian writers found Acridid blood plasma weakly alkaline, the pH values being 7.1-7-3 in Cdiptumus italicus (Tareeva and Nenyukov 1931 ;Skrjabina 1936a), 7-29 in Locusts migrabria and 7.39 in Dociostuurus maroccanus (Skrjabina,…”

Section: Dr B P Cvarov O I L Recent A~u I I L C I B Iia a C D O L mentioning

confidence: 95%

Recent Advances in Acridology: Anatomy and Physiology of Acrididae.

Uvarov¹

1948

Transactions of the Royal Entomological Society of London

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Studies on the Hydrogen-Ion Concentration of Insect Blood and Their Bearing on in vitro Cytological Technique

Cited by 18 publications

References 21 publications

Permeability of a Cell Membrane Junction

Permeability of a Cell Membrane Junction

The State of the Chromosomes in the Interphase Nucleus

Recent Advances in Acridology: Anatomy and Physiology of Acrididae.

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