Electron Microscopic Observations on Rous Sarcoma Virus and Cell Membranes

Dourmashkin, R. R.; Dougherty, Robert M.; Harris, Robert J.

doi:10.1038/1941116a0

Cited by 208 publications

(55 citation statements)

References 10 publications

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“…Recently Mum (61), using electron micrography, observed clear rings containing dark centres which were, in places, packed in hexagonal pattern. Similar observations were made by D ourmashkin et al (34). The hexagonal structure was due, however, to the action of saponin and, thus, considered by Bangham and H orne (4), G lauert et al (37), and H usson and L u zza ti (48) as artifact.…”

Section: Fig 2 Comparison Of Viscosity Of Suspensions Of Rigid Partsupporting

confidence: 71%

Molecular and Rheological Considerations of the Red Cell Membrane in View of the Internal Fluidity of the Red Cell

Dintenfass¹

1964

Acta Haematol

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Section: Fig 2 Comparison Of Viscosity Of Suspensions Of Rigid Partsupporting

confidence: 71%

Molecular and Rheological Considerations of the Red Cell Membrane in View of the Internal Fluidity of the Red Cell

Dintenfass¹

1964

Acta Haematol

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“…Hexachlorophene has been shown to alter the permeability of plant (24), bacterial (8,19,27), and mammalian erythrocyte membranes (7,12,23). Digitonin, a plant saponin, induces membrane damage by binding to cholesterol in the membrane (1,11). The results presented in this paper clearly show that both hexachlorophene and digitonin disrupt rat liver lysosomes and release enzymes.…”

Section: Discussionmentioning

confidence: 67%

Mechanism of Action of Miconazole: Labilization of Rat Liver Lysosomes In Vitro by Miconazole

Swamy

Joshi

Rao

1976

Antimicrob Agents Chemother

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Miconazole, a potent antifungal agent, labilizes rat liver lysosomes. Its labilizing effect is followed by measuring the release of lysosomal hydrolases, namely, acid phosphatase, (-glucuronidase, and arylsulfatase A. The effect of miconazole is concentration dependent in the range of 10-5 to 1.2 x 10-4 M. However, at higher concentrations, miconazole inhibits enzyme release but does not inhibit enzyme activities per se. The effect of miconazole depends on the drug/ lysosome ratio and is influenced by the pH of the incubation media, being minimal at alkaline pH. Membrane-active drugs such as nystatin, 2-phenethylalcohol, hexachlorophene, and digitonin have been compared with miconazole for their lysosome-labilizing action. The effect of miconazole on the lysosomal membrane is confirmed by a decrease in turbidity of the lysosomal suspension.Miconazole {1-[2,4-dichloro-,8-(2,4-dichlorobenzyloxy)-phenethyl]imidazole nitrate} has a broad spectrum of antimicrobial activity against pathogenic and nonpathogenic yeasts, dermatophytes, numerous saprophytic fungi, and gram-positive bacteria (13,25,31). Chemotherapeutic activity of miconazole as a topical applicant is well documented in the treatment of skin and nail infections and vaginal candidiasis (2,5,14,29,32). Studies on the mechanism of biological action of miconazole have been recently reported (9, 10, 28, 33; K. H. Sreedhara Swamy, M. Sirsi, and G. Ramananda Rao, Biochem. Pharmacol., in press). The drug induces leakage of intracellular materials from cells of Candida albicans (28), and at low concentrations it selectively inhibits the uptake of purines and glutamine into these cells (33). Electron microscopic examination of cells of C. albicans exposed to miconazole revealed that the earliest drug-induced alterations are seen at the plasma membrane (9, 10). Further, miconazole has been shown to induce hemolysis of mammalian erythrocytes and binds strongly to erythrocyte membrane lipoproteins (Sreedhara Swamy et al., in press). These investigations clearly indicate that the paramount feature of the biological action of miconazole is its interaction with cell membrane of sensitive organisms, resulting in the impairment of membrane function and eventually cell death.In an attempt to delineate the mode of action of miconazole on cellular and organellar membranes and to obtain a more comprehensive view of biological action, we have carried out studies on the interaction of miconazole with rat liver lysosomes. The present paper describes the effect of miconazole on the integrity of lysosomal membrane, providing further evidence that miconazole interacts with biological systems by impairing membrane function. MATERIALS AND METHODSChemicals. Miconazole nitrate was a gift sample from Ethnor Ltd., Bombay, India. Hexachlorophene, digitonin, 2-phenethylalcohol, p-nitrophenylphosphate, p-nitrocatechol sulfate, phenolphthalein-,-nglucuronide, Triton X-100, and tris(hydroxymethyl)-aminomethane (Trizma base) were purchased from Sigma Chemical Co., St. Louis, Mo. Nystatin was kin...

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“…Electron micrographs of negatively stained cholesterol membranes treated with Br-Fe showed a 'hole' pattern ( Fig. 3) (electron dense areas) similar to that produced in erythro cytes, and by saponin on erythrocyte membranes [7] and cholesterol membranes [1,9]. The ferritin was localized about and between the 'holes' (Fig.…”

Section: Resultsmentioning

confidence: 92%