Phosphatidic acid synthesis in the heart. 1. Effect of age and species difference in the mitochondrial and microsomal synthesis

1977 ◽  
Vol 55 (4) ◽  
pp. 308-314 ◽  
Author(s):  
K. J. Kako ◽  
G. Zaror-Behrens ◽  
S. D. Peckett
Keyword(s):  
Bovine Serum Albumin ◽  
Phosphatidic Acid ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Mitochondrial Fraction ◽  
Subcellular Fractions ◽  
Newborn Rats ◽  
Adult Rats ◽  
Rat Hearts ◽  
Weanling Rats

Rates of syntheses of monoacyl- and diacyl-glycerol 3-P (phosphate) were determined in the mitochondrial and microsomal fractions prepared from hearts of rats and rabbits, to compare characteristics of the acylation reactions by the two subcellular fractions. The assays were carried out with the subcellular fractions prepared from (i) hearts of hyperthyroid animals, and (ii) hearts of newborn and weanling rats. In addition, the effect of an addition of bovine serum albumin in the assay system was examined. (1) Administration of thyroid hormones increased the acyltransferase activity in rabbit hearts but not that in rat hearts. (2) Mitochondrial and microsomal fractions of hearts of newborn rats acylated glycerol 3-P at a rate 1.3–4 times greater than those of adult rats. The rate of acylation by the mitochondrial fraction of weanling rats was also high, but the rate of microsomal acylation was slightly lower than that of adult rats. By contrast, in newborn rats, diacylglycerol 3-P formation by the liver microsomes was not greater than that of the adults, although its formation by the newborn liver mitochondria was greater. (3) The accumulation of monoacylglycerol 3-P during the assay was accelerated by the addition of increasing amounts of bovine serum albumin. Therefore, the monoacylglycerol 3-P formation was less than 10% of the diacylglycerol 3-P formation in the assay containing no albumin and with the rat subcellular fractions, whereas nearly four times more monoacyl- than diacyl-glycerol 3-P was synthesized in the presence of 20 mg albumin. (4) The ratio of monoacyl- to diacyl-glycerol 3-P formation by the mitochondrial fraction was greater than that of microsomal fraction at any concentration of albumin in both rats and rabbits. At an equal albumin concentration in the assay, relatively more diacyl- than monoacyl-glycerol 3-P was formed in the mitochondrial fraction of newborn rat hearts as compared with adult hearts. (5) In conclusion, our data concerning the age and species differences in acyltransferase activities support a view that the mitochondrial fraction of both rat and rabbit hearts, in addition to the microsomal enzymes, is capable of catalyzing the de novo synthesis of phosphatidic acid.

scholarly journals Metabolism of free and esterified cholesterol by Leydig-cell tumour mitochondria

1973 ◽  
Vol 134 (2) ◽  
pp. 415-424 ◽  
Author(s):  
William R. Moyle ◽  
Robert L. Jungas ◽  
Roy O. Greep
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Leydig Cell ◽  
Bovine Serum ◽  
Incubation Temperature ◽  
Mitochondrial Fraction ◽  
Second Phase ◽  
Leydig Cell Tumour ◽  
Two Phases

1. Experiments were designed to localize intracellularly the enzymes and sterol substrates required for steroidogenesis in Leydig-cell tumours. Subcellular fractions were prepared by differential centrifugation of tumour homogenates. Both free and esterified cholesterol were associated primarily with the fractions sedimenting at 1400gav. and the lipid layer floating on the surface of the isolation tubes; they were not found in the mitochondria, where the conversion of cholesterol into pregnenolone occurred. 2. Hydrolysis of esterified cholesterol was required before it could be oxidized to pregnenolone. 3. An enzyme capable of hydrolysing cholesterol esters was located external to the mitochondria. 4. Mitochondria were subfractionated by allowing them to swell in 0.02m-phosphate buffer (pH7.2) and separating the inner and outer membranes by sedimentation in sucrose gradients. The outer membrane, identified by its content of monoamine oxidase, contained most of the cholesterol associated with the mitochondria. The inner membrane, identified by its content of succinate dehydrogenase, contained the cholesterol side-chain-cleaving enzyme and very little cholesterol. 5. Accumulation of sterols by the mitochondria was studied by incubating this fraction with labelled free and esterified cholesterol suspended in lipid-free bovine serum albumin. Two phases of cholesterol accumulation were observed. The first phase, requiring 10–15min, was independent of the incubation temperature, and was inhibited by the presence of bovine serum albumin in the incubation medium. The second phase of accumulation was independent of the serum albumin content of the medium but was inhibited by low incubation temperature. 6. Esterified cholesterol was not accumulated by the mitochondria after the initial rapid binding phase. 7. The findings suggest that cholesterol was not rapidly accumulated by the mitochondrial fraction in vitro and that mechanisms may be required to facilitate cholesterol transport into mitochondria in intact tumour cells during the periods in which steroidogenesis is stimulated maximally.

Improvement of an artificial test substrate technique for evaluation of em immunocytochemical labeling

1987 ◽  
Vol 45 ◽  
pp. 762-763
Author(s):  
G. D. Gagne ◽  
M. F. Miller
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Artificial Substrate ◽  
Chemical Fixation ◽  
As If

We recently described an artificial substrate system which could be used to optimize labeling parameters in EM immunocytochemistry (ICC). The system utilizes blocks of glutaraldehyde polymerized bovine serum albumin (BSA) into which an antigen is incorporated by a soaking procedure. The resulting antigen impregnated blocks can then be fixed and embedded as if they are pieces of tissue and the effects of fixation, embedding and other parameters on the ability of incorporated antigen to be immunocyto-chemically labeled can then be assessed. In developing this system further, we discovered that the BSA substrate can also be dried and then sectioned for immunolabeling with or without prior chemical fixation and without exposing the antigen to embedding reagents. The effects of fixation and embedding protocols can thus be evaluated separately.

Stability of Prostacyclin in Human Plasma and Whole Blood: Studies on the Protective Effect of Albumin

1981 ◽  
Vol 46 (03) ◽  
pp. 645-647 ◽  
Author(s):  
M A Orchard ◽  
C Robinson
Keyword(s):  
Platelet Aggregation ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Protective Effect ◽  
Whole Blood ◽  
Bovine Serum ◽  
Fatty Acid Content ◽  
Krebs Solution ◽  
Antiaggregatory Activity ◽  
Free Plasma

SummaryThe biological half-life of prostacyclin in Krebs solution, human cell-free plasma or whole blood was measured by bracket assay on ADP-induced platelet aggregation. At 37°C, pH 7.4, plasma and blood reduced the rate of loss of antiaggregatory activity compared with Krebs solution. The protective effect of plasma was greater than that of whole blood. This effect could be partially mimicked by the addition of human or bovine serum albumin to the Krebs solution. The stabilisation afforded by human serum albumin was dependent on the fatty acid content of the albumin, although this was less important for bovine serum albumin.

RADIOIMMUNOASSAY OF OESTRONE AND OESTRADIOL IN THE PERIPHERAL PLASMA OF THE DOMESTIC FOWL IN VARIOUS PHYSIOLOGICAL STATES AND OF HYPOPHYSECTOMIZED AND OVARIECTOMIZED FOWLS

1974 ◽  
Vol 75 (1) ◽  
pp. 133-140 ◽  
Author(s):  
B. E. Senior
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Diethyl Ether ◽  
Bovine Serum ◽  
Domestic Fowl ◽  
Laying Hens ◽  
Peripheral Plasma ◽  
The Mean ◽  
Precision And Accuracy ◽  
Chicken Ovary

ABSTRACT A radioimmunoassay was developed to measure the levels of oestrone and oestradiol in 0.5–1.0 ml of domestic fowl peripheral plasma. The oestrogens were extracted with diethyl ether, chromatographed on columns of Sephadex LH-20 and assayed with an antiserum prepared against oestradiol-17β-succinyl-bovine serum albumin using a 17 h incubation at 4°C. The specificity, sensitivity, precision and accuracy of the assays were satisfactory. Oestrogen concentrations were determined in the plasma of birds in various reproductive states. In laying hens the ranges of oestrone and oestradiol were 12–190 pg/ml and 29–327 pg/ml respectively. Levels in immature birds, in adult cockerels and in an ovariectomized hen were barely detectable. The mean concentrations of oestrone and oestradiol in the plasma of four non-laying hens (55 pg/ml and 72 pg/ml respectively) and one partially ovariectomized hen (71 pg/ml and 134 pg/ml respectively) were well within the range for laying hens. It is evident that the large, yolk-filled follicles are not the only source of oestrogens in the chicken ovary.

Interaction of 1,4,7,10-Tetraazacyclododecane-Co(Ⅱ) with Bovine Serum Albumin

2013 ◽  
Vol 30 (2) ◽  
pp. 232
Author(s):  
Fan LIU ◽  
Yuanqin ZHANG ◽  
Zhijin ZHANG
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum
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