Relationship between Partition Coefficients of Carboxylic Acids and Changes in Osmotic Resistance in Rat Erythrocytes In vitro

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The osmotic fragility (OF) of isolated Red Blood cells (RBCs) in guinea pigs and rats was examined by monocarboxylic, dicarboxylic and their partition coefficients. A phosphate-NaCl buffer solution that comprises each carboxylic acid at the concentration ranging from 0 to 100 mM was used to incubate dense-packed RBCs at 37°C for 60 minutes. The RBC suspensions were moved into OF test tubes containing NaCl from 0.1 to 0.8%. The hemoglobin concentration was determined and was observed that NaCl concentration induced 50% hemolysis as the OF value. The OF was was increased by dose dependently the exposure to some monocarboxylic acids that possessed hydrocarbon chains of more than 4 carbons in length in case of rats but no increase was observed in guinea pig RBCs. A positive correlation was obtained between the partition coefficients and the degree of change in OF for monocarboxylic acids in the rat, but not in guinea pig RBCs. On the other hand, dicarboxylic acids are corresponding to the monocarboxylic acids had either no effect or decreased OF in rat and guinea pig RBCs. There was no correlation between the partition coefficients and change in OF for monocarboxylic acids in only guinea pig RBCs but for dicarboxylic acids in both rat and guinea pig RBCs. The partition coefficients of the monocarboxylic acids were higher comparatively the corresponding dicarboxylic acids. Whereas monocarboxylic acids are thought to act on the hydrophobic acyl-chain of phospholipids in the deeper regions of the RBC membrane, dicarboxylic acids act on the hydrophilic interface and shallower areas of the RBC membrane. The fluidity index based on fatty acid composition was observed higher in the rat than the guinea pig RBC membrane. The difference in fatty acid composition was speculated to be one of the causes of different OF response to monocarboxylic acids between rat and guinea pig RBCs.

Section: Discussionmentioning

confidence: 85%

Section: Discussionmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effects of Carboxylic Acids on Osmotic Resistance in Rat and Guinea Pig Red Blood Cells in vitro: The Relationship between Partition Coefficient and Changes in Osmotic Fragility

Mineo¹

2018

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Carboxylic Acids with Certain Molecular Structures Decrease Osmotic Fragility against Osmotic Pressure in Cattle Erythrocytes In Vitro: Appearance of a Wedge-like Effect Similar to RBCs in Other Animal Species

Mineo¹,

Moriyoshi²

2019

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Osmotic fragility (OF) in red blood cells (RBCs) is a useful tool for evaluating the actions of various chemicals on the cell membrane in vitro. The effects of monocarboxylic and dicarboxylic acids on OF were evaluated in cattle RBCs. Isolated cattle RBCs were immersed in various carboxylic acids at 0-100 mM in a buffer solution for 1 hr and the 50% hemolysis was then determined by soaking in 0.1-0.8% NaCl solution. Although n-caprylic acid at 100 mM induced hemolysis, the other monocarboxylic acids possessing straight hydrocarbons did not affect OF. The dicarboxylic acids possessing straight hydrocarbons, except for glutaric acid, decreased OF in a dose-dependent manner. Some monocarboxylic acids with branched hydrocarbons tended to decrease OF, but these changes were not statistically significant. Although cyclopentanecarboxylic and cyclohexanecarboxylic acids at 100 mM decreased OF, other monocarboxylic acids with cyclic hydrocarbons did not affect OF. Among the dicarboxylic acids with cyclic hydrocarbons tested, only 1,2-cyclohexanedicarboxylic acid and phthalic acid with a benzene ring significantly decreased OF. There is no clear correlation between the effect of monocarboxylic or dicarboxylic acids on OF, and their partition coefficients. Thus, the partition coefficient is not a suitable parameter for explaining the effect of both groups of carboxylic acids on OF in cattle RBCs. With regard to the effect of monocarboxylic acids on OF, although an increase in OF was demonstrated in rat RBCs, no effect or rather a decrease in OF was demonstrated in cattle RBCs, similar to the results observed for guinea pig and sheep RBCs. With regard to the effect of dicarboxylic acids, decreases in OF were already demonstrated in rat, guinea pig and sheep RBCs. We have proposed that dicarboxylic acids exhibit a common stabilizing effect on the RBC membrane in various animals, which we termed a "wedge-like effect". We clarified that cattle RBCs also show a similar OF response to dicarboxylic acids in this experiment.

Carboxylic Acids with Certain Molecular Structures Strengthen the Cell Membrane against Osmotic Pressure in Sheep Erythrocytes In Vitro

Mineo¹,

Noji²,

Watanabe³

et al. 2018

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In sheep red blood cells (RBCs), considering osmotic fragility (OF) as an indicator, the reaction of monocarboxylic and dicarboxylic acids on membrane resistance to osmotic pressure were evaluated. Sheep RBCs were exposed to carboxylic acids at 0-100 mM in a buffer solution for 1 h and the 50% hemolysis was then determined by soaking in 0.1-0.8% NaCl solution. Although formic acid declined and n-caprylic acid increased OF, most of the monocarboxylic acids with straight hydrocarbon chains did not change OF in sheep RBCs. Whereas, all the tested dicarboxylic acids with straight hydrocarbon chains decreased OF with the degree of the decrease in OF dependent on the compound. Some monocarboxylic acids with branched or cyclic (including a benzene ring) hydrocarbon chains decreased OF with the degree of the decrease dependent on the number of carbons and form of branching in the hydrocarbon chain. Dicarboxylic acids with a cyclohexane ring or benzene ring decreased or tended to decrease OF with the degree of the decrease dependent on the position of the two carboxylic groups. There is no clear correlation between the effect of monocarboxylic or dicarboxylic acids on OF, and their partition coefficients. Thus the partition coefficient is not a suitable parameter for explaining the effect of both groups of carboxylic acid on the cell membrane as evaluated by the change in OF in sheep RBCs. It is speculated that the space composed of the acyl-chains of the phospholipids, into which hydrophobic hydrocarbons can enter to form a more rigid structure through their subsequent interaction, is an important factor related to the OF-decreasing effect of carboxylic acids.