Effect of Alloxan Diabetes and Subsequent Insulin Treatment on Temperature Kinetics Properties of Succinate Oxidase Activity in Rat Kidney Mitochondria

AbstractWe evaluated early and late effects of alloxan-diabetes and subsequent insulin treatment on the kinetic properties of succinate oxidase (SO) in rat liver mitochondria. Diabetic state lowered the SO activity; insulin treatment was effective in restoring the activity only in oneweek diabetic rats. The energies of activation in low and high temperature ranges (EH and EL) decreased significantly in diabetic animals; once again insulin treatment was partially effective only in the one-week diabetic group. The total phospholipids (TPL) and cholesterol (CHL) contents did not change in one-week groups. In one-month diabetic animals TPL decreased while CHL increased; insulin treatment induced further changes without restoring normality. The lysophospholipid (Lyso), sphingomyelin (SPM), phosphatidylinositol (PI) and phosphatidylserine (PS) content increased in the diabetic state while phosphatidylcholine (PC) and phosphatidylethanolamine (PE) decreased. Insulin treatment had a partial restorative effect. The changes in EH correlated negatively with SPM. The phase transition temperature, Tt, decreased in diabetic and insulin-treated groups. These changes correlated positively with the ratios of TPL/PI and TPL/PS. The membrane fluidity decreased in the diabetic state; insulin had a restorative effect only in the one-week group.

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Glucocorticoids decrease cytochrome c oxidase activity of isolated rat kidney mitochondria

FEBS Letters ◽

10.1016/s0014-5793(98)01033-3 ◽

1998 ◽

Vol 435 (1) ◽

pp. 25-28 ◽

Cited By ~ 35

Author(s):

Nicolas Simon ◽

Pascale Jolliet ◽

Christophe Morin ◽

Roland Zini ◽

Saı̈k Urien ◽

...

Keyword(s):

Cytochrome C ◽

Cytochrome C Oxidase ◽

Oxidase Activity ◽

Rat Kidney ◽

Kidney Mitochondria ◽

Isolated Rat Kidney ◽

Isolated Rat

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Syngeneic transplantation of fetal rat pancreas. I. Effect of insulin treatment of the reversal of alloxan diabetes

Diabetes ◽

10.2337/diabetes.27.10.982 ◽

1978 ◽

Vol 27 (10) ◽

pp. 982-987 ◽

Cited By ~ 6

Author(s):

R. C. McEvoy ◽

R. V. Schmitt ◽

O. D. Hegre

Keyword(s):

Alloxan Diabetes ◽

Insulin Treatment ◽

Rat Pancreas ◽

Fetal Rat

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Mechanism of inhibition of succinate oxidase by products of oxidation of o-dihydroxycoumarins

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19800641 ◽

1980 ◽

Vol 45 (2) ◽

pp. 641-652

Author(s):

Petr Zbořil

Keyword(s):

Inhibitory Activity ◽

Oxidase Activity ◽

Enzyme Preparation ◽

Inhibitory Effects ◽

Anaerobic Conditions ◽

Long Period ◽

Mechanism Of Inhibition ◽

Intermediary Product ◽

Succinate Oxidase ◽

By Products

Semiquinone is an intermediary product of the oxidation of daphnetin (7,8-dihydroxycoumarin) and esculetin (6,7-dihydroxycoumarin) by diphenol oxidase; its concentration rapidly decreases. When the oxidation is effected by ferricytochrome c, the concentration of the semiquinone remains practically constant for a long period. Similarly, the ability of the products of daphnetin oxidation by diphenol oxidase to inhibit succinate oxidase activity in mitochondrial fragments rapidly decreases with time; the decrease is considerably slower in the case of cytochrome c. The inhibitory activity of the product decreases with time also during esculetin oxidation by ferricyanide. This indicates that the inhibitory effects must be ascribed predominantly to the semiquinone, the quinone is less efficient. The inhibition of succinate oxidase or succinate dehydrogenase was strongly decreased when the enzyme preparation of Keilin and Hartree was incubated with esculetin and ferricyanide in the presence of KCN or under anaerobic conditions. This demonstrates that the reaction of the inhibitor with the enzyme either involves subsequent oxidations or that the inhibitor preferentially reacts with the oxidized form of the sensitive component of the respiratory chain. The second alternative is very little probable since there is no correlation between the degree of inhibition and the binding of the inhibitor to mitochondrial fragments.

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