Jerzy Popinigis

Anaerobic and Aerobic Enzyme Activities in Human Skeletal Muscle from Children and Adults

Literature has shown that children have lower anaerobic capacity and oxidize more lipids during aerobic activity compared with adults. The purpose of the present study was to examine the effects of age on the activity of marker enzymes for anaerobic and aerobic metabolism in human skeletal muscle from relatively sedentary children and adults. The m. obliquus internus abdominis was analyzed for anaerobic [creatine kinase, adenylate kinase, and lactate dehydrogenase (LDH)] and aerobic (carnitine palmitoyltransferase and 2-oxoglutarate dehydrogenase) enzyme activities in 32 male individuals. The subjects were divided into two groups: children (3–11 y; n = 20) and adults (29–54 y; n = 12). LDH activity was higher in adults (118.2 ± 20.1) compared with children (27.8 ± 10.1) μmol · min−1 · g−1 wet weight (p < 0.0002). Creatine kinase activity was 28% (p < 0.0003) lower in children than in adults, and adenylate kinase activity was 20% (p < 0.006) lower in children than in adults. In addition, we found higher 2-oxoglutarate dehydrogenase activity in adults compared with children (p < 0.04), with no effect of age on carnitine palmitoyltransferase activity (NS). When samples were expressed relative to protein content, only LDH activity remained significantly lower in children compared with adults (p < 0.0001). In conclusion, the lower LDH activity observed in children compared with adults may partially explain decreased anaerobic and lactate generation capacity of the children studied. However, the mechanisms for the relatively deficient anaerobic enzyme activities of children are not clear.

Effects of indolinic and quinolinic aminoxyls on protein and lipid peroxidation of rat liver microsomes

A study on peroxyl radical induced oxidation of rat liver microsomal membranes in the presence of different indolinic and quinolinic aminoxyls (Scheme 1) was carried out in order to test their efficiency as antioxidants in lipid and protein peroxidation. The extent of lipid peroxidation was quantified by the amount of malondialdehyde (MDA) produced, and the measurement of carbonyl residues was used as an index of microsomal protein oxidation. The results obtained suggest that lipid soluble indolinic and quinolinic aminoxyls are efficient in protecting lipids and proteins of biological membranes against oxidation. The efficacy of these aminoxyls as protectors of lipids and proteins was much higher than the water soluble TEMPOL. Moreover, the hydrophobic aminoxyls were more effective in preventing protein than lipid oxidation at low concentrations (1-20 microM). However, at high concentration (100 microM), lipid as opposed to protein oxidation was almost completely inhibited. The data supports the hypothesis that proteins probably have a different oxidation pattern from lipids.

Indolinonic and quinolinic aminoxyls as protectants against oxidative stress

A study on thermally and peroxyl radical induced oxidation of linolenic acid micelles in the presence of different concentrations of aminoxyls was carried out in order to test their efficiency as antioxidants in lipid peroxidation. The extent of peroxidation was measured by the malondialdehyde (MDA) produced and by oxygen consumption evaluated using an oxygraph. The results obtained indicate that indolinonic and quinolinic aminoxyls synthesized by us could be used as effective antioxidants in biological systems.

Effects of Alkyl Alcohols and Related Chemicals on Rat Liver Structure and Function

The effects of alkyl alcohols and related chemicals on the ultrastructure of mitochondria in the rat hepatocyte were studied. The following three different groups of chemicals were tested: Group 1: alkyl alcohols with straight carbon chains (ethanol, 1 propanol, 1 butanol, 1 pentanol, 1 octanol, 1 dodecanol and 1‐octadecanol); Group 2 :tert and cyclo‐compounds (tert‐butanol, cyclo‐pentanol, and cyclo hexanol); and Group 3: polyhydroxy alcohols (ethylene glycol, propylene glycol, 1,3 propandiol, glycerol and pentaerythritol). Results obtained were summarized as follows: 1) Ethanol, 1 propanol, 1 butanol, 1‐pentanol and 1 octanol had essentially the same effects on the mitochondrial ultrastructure: a mixed population of small and enlarged mitochondria with poorly developed cristae; 1‐dodecanol induced ultrastructural changes of mitochondria of two distinct types: a mixed population of small and enlarged mitochondria with poorly developed cristae in some hepatocytes and remarkably enlarged mitochondria with well developed cristae in others; and 1 octadecanol induced remarkably enlarged mitochondria in all hepatocytes. 2) Chemicals belonging to group 2 and group 3 induced essentially the same changes as those induced by 1‐octadecanol. More than one month was required to induce those changes. The mechanism by which those ultrastructural mitochondrial changes were induced is not clear, but the present results may suggest that the hydroxy group (‐OH) common to all these chemicals in some way accounts for the phenomenon. Acta Pathol Jpn 41: 405 413, 1991.

Effects of Alkyl Alcohols and Related Chemicals on Rat Liver Structure and Function: III. Physicochemical Properties of Ethanol-, Propanol- and Butanol-treated Rat Liver Mitochondrial Membranes

The physicochemical properties of mitochondria in liver tissue obtained from rats given 32% ethanol, 32% propanol or 6.9% butanol in drinking water for up to 3 months were investigated using differential scanning calo‐rimetry and fluorescence polarization measurements. The results obtained were as follows: 1) Phospholipids extracted from mitochondria showed increases in the relative amounts of phosphatidylcholine, phosphatidylinositol and phosphatidylserine, and a decrease in the relative amount of phosphatidylethanolamine. An increase in the unsatu‐rated/saturated fatty acid ratio of phospholipids was also observed. 2) Elevation of the thermotropic lipid phase transition temperature with a decrease in the enthalpy value (δH) was revealed by differential scanning calo‐rimetry. 3) The elevation of the lipid phase transition temperature was detected also by fluorescence polarization measurements using 1,6 diphenyl 1, 3, 5 hexatriene (DPH) as a probe. Elevation of mitochondrial membrane fluidity was found in some of the experimental animals, but most showed no changes in comparison with the control. A possible role of membrane fusion in the mechanism of formation of ethanol‐, propanol‐ and butanol induced hepatic megamitochondria is discussed on the basis of these results. Acta Pathol Jpn 42: 549–557, 1992.

Suppression of the hydrazine-induced formation of megamitochondria in the rat liver by coenzyme Q10

The effects of coenzyme Q10 (CoQ10) on the hydrazine-induced changes in the structure of mitochondria and those in antioxidant systems of the liver were investigated using rats as experimental animals. Animals were placed on a powdered diet containing 1.0% hydrazine for 7-8 days in the presence or absence of the combined treatment with CoQ10. Results obtained were as follows: (a) treatment of animals with CoQ10 prevented the hydrazine-induced formation of megamitochondria in the liver; (b) changes observed in the liver of the hydrazine-treated animals in comparison to the control were increases in the contents of α-tocopherol and CoQ analogs, increases in the levels of lipid peroxidation, decreases in the level of reduced glutathione with increases in that of oxidized glutathione, and increases in the ratio of unsaturated to saturated fatty acids in phospholipid domains of mitochondrial membranes; and (c) administration of CoQ10 to hydrazine-treated animals suppressed enhanced lipid peroxidation and improved lowered adenosine diphosphate/O ratios of mitochondria. The present data suggest that CoQ10 suppresses the hydrazine-induced formation of megamitochondria by scavenging free radicals generated from hydrazine and its metabolites.

Studies on urea synthesis in the liver of rats treated chronically with ethanol using perfused livers, isolated hepatocytes, and mitochondria

Changes in urea synthesis in the liver of rats treated with 32% ethanol in the drinking water for up to 6 months were studied using perfused livers, isolated hepatocytes, and mitochondria. Results obtained from ethanol-treated rats are summarized as follows: (1) the mitochondria of the hepatocytes of rats treated with ethanol for 2 months or longer became enlarged to various degrees, (2) the levels of ammonia in the serum remained within a normal range, while those in liver tissue were elevated compared with the control, (3) urea synthesis from ammonia in perfused livers was decreased markedly, while that from citrulline remained in the normal range, (4) the activities of carbamyl phosphate synthetase (CPS; EC 2.7.2.5) and ornithine transcarbamylase (OTC; EC 2.1.3.3) in mitochondria were unchanged compared with those of the control, and (5) the levels of ATP in liver tissue and the ability of mitochondria to synthesize ATP were decreased markedly compared with the control. Both the level of ATP in the hepatocytes and the synthesis of urea from ammonia by perfused livers of rats treated with ethanol were resistant to externally added ethanol, while those of control animals were severely affected. These results suggest that the intracellular level of ATP is intimately related to urea synthesis in both control and ethanol-treated animals, and lowered levels of ATP may be a key factor in the suppression of urea synthesis in ethanol-treated animals.

Cerulein-induced acute pancreatitis diminished vitamin E concentration in plasma and increased in the pancreas.

SummaryRedistribution of vitamin E in the rat body was studied during acute pancreatitis induced by two intraperitoneal doses of cerulein 40 μg/kg of body weight at 1-hr intervals. Hyperamylasemia (2064±521 vs 6419±129 U/dL) and pancreatic edema (pancreatic water content, 71±1.2% vs 78±2%) were observed. In this model the increased level of lipid soluble fluorophore was also observed (274±18 vs 120±9.0 relative fluorescence per g dry wt). Parallel with these changes was a decrease in the level of vitamin E in the serum and an increase in the pancreas. The concentration of vitamin E in the pancreas after 6h was 162±8.5 ng/mg dry mass vs 128.1 ±6.1 ng/mg dry mass in control animals. The effect of heparin on vitamin E redistribution induced by acute pancreatitis was also investigated. It was found that heparin at a dose of 100 U/kg body mass prevents the drop of the vitamin E level in the serum as well as the increases in the concentration in the pancreas tissue. It was concluded that acute pancreatitis induced redistribution of vitamin E in the rat body. Moreover, we studied the effects of heparin treatment on oxidative stress in the pancreas tissue. Acute pancreatitis caused an increase in lipofuscin accumulation, and a decrease in protein sulfhydryl groups in citrate synthetase (CS) and in malate dehydrogenase (MDH) activity. Heparin treatment that protected vitamin E accumulation in the pancreas tissue did not influence the changes in the level of lipofuscin and proteins sulfhydryl. On the other hand rats treated with heparin showed a greater decrease in CS and MDH activities.

Butylmalonate counteracts the inhibitory effect of protamine on succinate oxidation. An ultrastructural interpretation

Abstract When rat liver mitochondria were exposed to protamine or butylmalonate, succinate oxidation was inhibited. However, butylmalonate was found to release the inhibitory effect of protamine on succinate oxidation in mitochondria. Electron microscopic study carried out in the present study showed that protamine induced “orthodox” configuration in which the matrix space was maximally expanded eliminating the intracristal space, whereas butylmalonate highly contracted the matrix space thus expanding the intracristal space. Butylmalonate overcame the effect of protamine on mitochondrial configuration, specified above, expanding the intracristal space. The mechanism of the opposite action of butylmalonate in the presence and absence of protamine on succinate oxidation was correlated to the configurational changes of the mitochondrion.