Phospholipid fatty acid and lipid peroxidation in liver microsomes from guinea pigs fed oil related to the toxic oil syndrome.

The potential effects of oil specimens both related and unrelated to cases of Toxic Oil Syndrome (TOS) on the phospholipid fatty acid composition, some antioxidant enzyme activities, and lipid peroxidation in guinea pig liver microsomes were investigated. For 4 weeks, animals were fed diets supplemented with either oil related to cases of TOS or control oil, previously heated or not. In all cases, the fat diet produced the incorporation of approximately 7% of linoleic acid exclusively in the phosphatidylethanolamine (PE) of liver microsomes. A pronounced increase in lipid peroxidation products, measured as malondialdehyde (MDA) and 4-hydroxyalkenals, was detected in animals fed nonheated control oil. Heated oil diets produced significant increases in superoxide dismutase and glutathione peroxidase activities with concomitant decreases in the lipid peroxidation status. Heated oils also increased the oleic/stearic acid ratio in the phosphatidylserine plus phosphatidylinositol (PS + PI) fraction. This ratio was also increased in the same fraction from animals fed non heated case oil. The study shows that case oil produces a decrease in the lipid peroxidation products with minimal alterations in phospholipid fatty acid composition of liver microsomes, which is dependent rather on the composition of dietary fat than on toxic effects.

Evaluation of patterns of urinary proteins by SDS-PAGE in rats of different ages.

The patterns of urinary proteins in rats of different ages were examined on SDS gradient polyacrylamide gel electrophoresis coupled with silver staining. Proteins were fractionated into at least 26 bands. Densitometric measurements were used to characterize protein excretion patterns. The results showed that proteinuria in newborn, young and adult rats is predominantly tubular, consisting of low molecular-weight species. Conversely, late adults and old rats had a mixed glomerular pattern, with a steadily increasing excretion of albumin, IgG and transferrin, as was the case of other high molecular-weight proteins. Fragments of both immunoglobulins and albumin were found in all urine samples assayed. In 1 month old rats the percentage of Tamm-Hörsfall (T-H) protein was higher (P < 0.01) than in the remaining groups studied. In newborns, relatively high albumin, IgG and transferrin percentages were detected, as well as an alpha 1-acid glycoprotein and carbonic anhydrase excretion (P < 0.05 and P < 0.01 respectively) higher than that observed in the other age groups studied.

Effect of intestinal ischemia on pulmonary surfactant. An experimental study.

The infective factor seems to be very important in the physiopathology of intestinal ischaemia syndrome, as we suggested in previous research works, and is probably responsible for the disturbances observed in pulmonary surfactant. In the present research project, 48 mongrel dogs were studied under different situations of experimental intestinal ischaemia (arterial, venous and revascularization) after laparotomy and the pulmonary surfactant was determined in all cases. We conclude that the observed changes in phospholipids (phosphatidylglycerol and phosphatidylinositol particularly) can be directly related to the infective factor and important enough to induce physicochemical alterations of the surfactant and subsequently pulmonary function.

Heterogeneity of acid beta-galactosidase from rabbit kidney.

1. Rabbit kidney acid beta-galactosidase can be resolved into three peaks (named A3, A2 and A1) by gel-filtration chromatography. Their estimated molecular weights were: more than 250,000, 150,000 and 17,000 respectively. 2. The purified acid form appeared as a single band of protein (Mr = 28,000) on electrophoresis in the presence of sodium dodecyl sulphate, suggesting that forms A3 and A2 are multimeric forms of beta-galactosidase A1. 3. Treatment with neuraminidase from Clostridium perfringens converts form A3 into a more basic form. This phenomenon occurs also when this form is stored for a week at 4 degrees C and parallels its disaggregation. 4. The data suggest that the sialic acids present in the multimeric forms are involved in the aggregation of the acidic form of beta-galactosidase.

Alterations in the activities of subcellular fractions marker enzymes in rat liver and brain by hydrocortisone and corticosterone treatment.

The effect of subcutaneous injection of hydrocortisone and corticosterone on the activity values of some subcellular fractions marker enzymes from rat liver and brain was investigated and compared with controls (without treatment with hormones). The following enzymes were studied (subcellular fraction are shown between parentheses): N-acetyl-beta-D-glucosaminidase and beta-glucuronidase (lysosomes); succinate dehydrogenase = SDH (mitochondria); glucose-6-phosphatase (endoplasmic reticulum); 5'-nucleotidase and Na+-K+-Mg2+ ATPase (plasma membrane). The specific activity of lysosomal enzymes from liver showed no change when rats were injected either with hydrocortisone or corticosterone. The same enzymes from brain showed significant increases in their activities with both hydrocortisone or corticosterone except beta-glucuronidase; this enzyme gave activity values remaining between the control levels, after treatment with corticosterone. The activity of mitochondrial SDH was increased after corticosterone injection either in liver or brain. After hydrocortisone injection, its activity rises significantly in brain (72%), but it falls in liver compared to the control values. Glucose-6-phosphatase behaves similarly in brain or liver fractions; its activity increases always after corticosterone treatment and decreases by hydrocortisone. The plasma membrane marker enzymes did not change practically in brain fractions, excepted Na+-K+-Mg2+ ATPase which tends to rise its activity after hydrocortisone injection. In liver fractions, both 5'-nucleotidase and Na+-K+-Mg2+ ATPase activities increase either by corticosterone or hydrocortisone treatment, except 5'-nucleotidase which specific activity decreases in liver after hydrocortisone treatment.

Effects of oestradiol, testosterone and medroxyprogesterone on subcellular fraction marker enzyme activities from rat liver and brain.

The following enzymes have been studied (subcellular fractions are shown between parentheses): NAG and beta-glucuronidase (lysosomes); SDH (mitochondrial); glucose-6-phosphatase (endoplasmic reticulum); 5'-nucleotidase and (Na+, K+)Mg2+ ATPase (plasma membranes). Alterations on their activities were observed after subcutaneous injection of sex hormones, compared with controls. NAG activity from liver was always significantly decreased in lysosomal and microsomal fractions after the hormonal treatment. In the same conditions, NAG from brain was always increased. beta-Glucuronidase behaves like NAG in brain; in liver it was not modified by testosterone and it was slightly increased in lysosomal fraction after oestradiol treatment. SDH activity was not modified in mitochondrial fractions from liver, but this activity was always significantly increased in brain. Glucose-6-phosphatase activity was always significantly decreased in microsomal fractions from liver. It was increased in brain after oestradiol and testosterone injection, but medroxyprogesterone treatment caused a decreased activity. 5'-Nucleotidase and (Na+, K+)Mg2+ ATPase from brain were significantly increased in microsomal fractions by oestradiol and testosterone. Medroxyprogesterone, however, caused an increase in ATPase, but did not affect 5'-nucleotidase. Both activities in liver were decreased by oestradiol and increased by testosterone, but medroxyprogesterone caused (Na+, K+)Mg2+ ATPase to rise and 5'-nucleotidase to fall.

Heterogeneity of beta-galactosidase from rabbit spleen. Separation and characterization of different forms.

Two forms, I and II, of an acid beta-galactosidase from rabbit spleen were separated by DEAE-cellulose chromatography and then characterized. Both forms of the enzyme showed different heat-stability (form I being heat-labile and form II heat-stable), and different pI (6.7 for form I and 5.3 and 6.7 for form II). Their gel filtration patterns were also different: form I was resolved in a single peak of mol. wt. 75,000, whereas form II was resolved in one or two peaks of mol. wt. 120,000 and greater than 200,000, depending on the pH of elution. However, both forms had similar pH stability and behavior toward alpha-methyl-beta-D-galactopyranoside, alpha-methyl-beta-D-glucopyranoside, urea and KCl. Differences in pH optima, optimal temperature and Km values were not marked.

[Purification of solubilized fucosyltransferase from lamb brain using ethylagarose gel]. / Purification de la fucosyl-transférase solubilisée du cerveau d'Agneau : utilisation d'un gel d'éthylagarose.

The glycoprotein: fucosyl-transferase of the cerebral hemispheres, assayed with desialylated fetuin as exogenous acceptor, was the most active of the protein: glycosyltransferases tested in the brain. The addition of Titron X-100 to the membrane suspension, followed by high speed centrifugation, led to a solubilization of the enzyme. The use of hydrophobic chromatography on ethylagarose gave a good purification of this solubilized fucosyl-transferase, whose homogeneity has been shown by Ultrogel AcA 22, DEAE-cellulose chromatography and disc electrophoresis.