Mitochondrial permeability for alcohols, aldoses, and amino acids

Nobel, Park S.

doi:10.1007/bf01870006

Cited by 6 publications

(1 citation statement)

References 22 publications

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“…Finally, two studies deal with alcohol effects on permeability proper. In one, permeation of alcohols into mitochondria was found to decrease as the number of OH groups increases ( 17). In the other, with an artificially thin lipid membrane from sheep red cells, Gutknecht and Tosteson (4) reported that aliphatic alcohols lower the resistance of this membrane to ions and especially that they increase its permeability to K+.…”

Section: Discussionmentioning

confidence: 99%

The Influence of Aliphatic Alcohols on Leaf Senescence

Satler¹,

Thimann²

1980

Plant Physiol.

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Because of the effects of ethanol used as a solvent in other experiments, the action of aliphatic alcohols on leaf senescence in the dark has been studied systematically. These compounds both maintain chlorophyll and prevent proteolysis in the dark, much as do the cytokinins and other senescence-delaying substances. The activity of the straight-chain alcohols increases in a log-linear fashion with increasing chain length up to 1-octanol. Introduction of a branch in the chain or of a second OH group greatly decreases, or in some cases annuls, the antisenescence activity. In all cases, the action on senescence is closely (although not always exactly) paralleled by opening of the stomata. Abscisic acid and exposure to high concentrations of osmoticum, both of which close the stomata, antagonize the action of the alcohols. Some interactions with other agents are noted. The effects are compared with reported effects on seed germination, on hemolysis and animal membranes, and especially on permeability to K' ions, and a tentative basis for the mechanism of action is advanced.The ability of a number of chemically unrelated compounds to exert striking modifications of the progress of senescence in the detached leaves of oat seedlings has been reported elsewhere (22,24, and literature cited therein). Besides the cytokinins, at least five different compounds act to delay senescence in the dark, whereas three, as well as two physical treatments, promote the slower rate of senescence in the light, thus antagonizing the delaying effect of light. We found that in all cases the action on senescence was paralleled by an action on the stomatal aperture; stomatal closure paralleled promotion of senescence and stomatal opening paralleled its delay or inhibition.In studying these effects, it was necessary on several occasions to use alcohol as a solvent. Although the ethanol was diluted down to a maximum of 1% before application of the solution to the leaves, we noted that controls floated on this aqueous alcohol in darkness behaved very differently from those floated on H20. An example, with two concentrations of ethanol, is shown in Table I. Figures I and 2 of reference 24 also showed alcohol effects, but these were superimposed on the effects of FC2. It is clear from these data that ethanol exerts an effect on senescence in darkness like that of the several senescence inhibitors, although more weakly. Repeated observations of this alcohol effect led to a study of the action of a number of aliphatic alcohols on senescence. In this paper we report the considerable activity of a series of aliphatic alcohols in preventing or delaying leaf senescence in the dark. Disappearance of Chl and proteolysis responded similarly in all cases examined. The relation between structure and activity 'This work was supported in part by Grant BMS 7683126 from the National Science Foundation (to K. V. T.).2 Abbreviations: FC: fusicoccin; CCCP: carbonyl cyanide m-chlorophenylhydrazone. among the alcohols is closely parallel to reported effects...

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Section: Discussionmentioning

confidence: 99%

The Influence of Aliphatic Alcohols on Leaf Senescence

Satler¹,

Thimann²

1980

Plant Physiol.

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The effects of temperature and thermal acclimation upon the osmotic properties and nonelectrolyte permeability of liver and gill mitochondria from rainbow trout (Salmo gairdneri)

Hazel

Schuster

1976

J. Exp. Zool.

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Thermal acclimation of rainbow trout (Salmo gairdneri) taken from 20 degrees C to 7 degrees C resulted in adaptation of mitochondrial function, as evidenced by increases in the specific activities of NADH- and succinate-cytochrome c reductase of 1.93- and 2.7-fold respectively. Mitochondria from both gill and liver obeyed the Boyle-van't Hoff relationship in the range from 400 to 60 mosM. Thermal acclimation had no effect on the osmotic properties of liver mitochondria, whereas gill mitochondria from cold-acclimated trout were more sensitive to osmotic swelling than mitochondria from warm-acclimated individuals. The non-electrolyte permeability of liver mitochondria was assessed by optically monitoring mitochondrial swelling rates in isosmotic solutions of urea, glycerol, mannitol and glucose. Two parameters of mitochondrial swelling were determined: (a) initial swelling rates, d(1/A)dt, and (b) swelling constants, ks, derived from the time required to swell a fixed volume. Regardless of the assay temperature or the permeant employed, liver mitochondria from cold-acclimated trout exhibited greater initial swelling rates than mitochondria from warm-acclimated trout, indicating properties of temperature-compensated permeability. The apparent ranking of nonelectrolyte permeabilities was urea greater than glycerol greater than mannitol greater than glucose. ks values for urea and glycerol from cold-acclimated trout were greater than values typical of warm-acclimated populations; however ks values for glucose and mannitol were not influenced by thermal acclimation. Regardless of the permeant considered, activation energies for ks values were 3- to 5-fold greater than those for initial swelling rates. The time course of mitochondrial swelling consists of two components, an initial rapid swelling phase characterized by a half-life of 3-12 seconds, and a slower swelling phase characterized by a half life of 1-6 minutes. Initial swelling rates, which approximate the rapid swelling component, are considered to be the least ambiguous index of permeability, whereas ks values are more complex and strongly influenced by the slower swelling component.

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Chloroplast Reflection Coefficients: Influence of Partition Coefficients, Carriers, and Membrane Phase Transitions

Nobel¹

1974

Membrane Transport in Plants

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Mitochondrial permeability for alcohols, aldoses, and amino acids

Cited by 6 publications

References 22 publications

The Influence of Aliphatic Alcohols on Leaf Senescence

The Influence of Aliphatic Alcohols on Leaf Senescence

The effects of temperature and thermal acclimation upon the osmotic properties and nonelectrolyte permeability of liver and gill mitochondria from rainbow trout (Salmo gairdneri)

Chloroplast Reflection Coefficients: Influence of Partition Coefficients, Carriers, and Membrane Phase Transitions

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