scholarly journals A modified radioimmunoassay of aldosterone

1995 ◽  
Vol 41 (2) ◽  
pp. 33-34
Author(s):  
N. P. Goncharov ◽  
G. V. Katsiya ◽  
V. Yu. Butnev ◽  
L. B. Khagundokova
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Adrenal Cortex ◽  
Bovine Serum ◽  
High Specificity ◽  
New Method ◽  
Isolation And Purification ◽  
Cross Reactions ◽  
Chromatographic Isolation

A method of radioimmunoassay of aldosterone in the blood of humans and monkeys has been developed. Antiserum was prepared on rabbits against aldosterone-3-(0-carboxymethyloxime) conjugate with bovine serum albumin. The specificity of antiserum was tested in cross-reactions with 32 related steroids. High specificity of the antiserum in this method helped measure aldosterone levels without preliminary chromatographic isolation and purification of this compound. The sensitivity of the new method is 12.5 pg per 0.1 ml. Reproducibility of the method between different series of measurements was no more than 15%, within the same series below 12%. The method was used to assess the mineralocorticoid function of the adrenal cortex of man and monkeys.

scholarly journals THE RETENTION OF S35-LABELLED BOVINE SERUM ALBUMIN IN NORMAL AND IMMUNIZED RABBIT LIVER TISSUE

1957 ◽  
Vol 105 (4) ◽  
pp. 361-372 ◽  
Author(s):  
Justine S. Garvey ◽  
Dan H. Campbell
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Ribonucleic Acid ◽  
Bovine Serum ◽  
Liver Tissue ◽  
Rabbit Liver ◽  
New Method ◽  
Retention Data ◽  
Tissue Extracts ◽  
Antigen Material

The S35-label of S35-BSA was detected in the liver tissue of rabbits to the extent of 0.02 per cent (10 µg or ≃ 1014 molecules) of the injected material at 140 days after injection. The rate of loss of antigen at the termination of the experiment was of such an order that significant amounts would be expected to persist for at least several years. Data are reported which extend the retention data previously reported on S35-labelled hemocyanin. They indicate that amounts of the order of 0.05 per cent (25 µg.) of antigen material persist at 330 days after injection. All of the radioactivity of material retained in the liver tissue 6 weeks after injection was immunologically related to the original S35-BSA antigen. Preliminary studies are reported which indicate that the retained antigen is bound to ribonucleic acid. A new method is described for the isolation of p-azophenylsulfonate bovine serum albumin from tissue extracts by means of a Dowex 2 adsorbent.

Sensitive Radioimmunoassay for Detection of O6-Ethyldeoxyguanosine in D N A Exposed to the Carcinogen Ethylnitrosourea in vivo or in vitro

1978 ◽  
Vol 33 (11-12) ◽  
pp. 897-901 ◽  
Author(s):  
Rolf Müller ◽  
Manfred F Rajewsky
Keyword(s):  
Nucleic Acid ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Bovine Serum ◽  
Association Constant ◽  
High Specificity ◽  
Diploid Cell ◽  
Molar Ratio

O8-ethyl-2′-deoxyguanosine (O8-EtdGuo) is a major premutational product formed in both in­tracellular DNA and in purified DNA in vitro, after exposure to the potent alkylating carcinogen N-ethyl-N-nitrosourea (EtNU). Antibodies directed against O8-EtdGuo were obtained by immunizing rabbits with a conjungate of O6-EtGuo and bovine serum albumin. In a competitive radioimmuno­assay (RIA), with O8-Et[8,5′·3H]dGuo as a tracer and various alkylated and natural nucleic acid components as inhibitors, these antibodies show high specificity for O6-EtdGuo and detect this product at a level of 0.3 picomol (antibody association constant, 7×108l/mol). In a sample of 130 μg of hydrolyzed DNA, O6-EtdGuo can thus be measured at a molar ratio of O8-EtdGuo/2′- deoxyguanosine of about 3×10-8, i. e., about 5×103 O8-EtdGuo molecules per diploid cell. Exam­ples are given for the quantitation of Oe-EtdGuo in DNA exposed to EtNU in vivo or in vitro.

RADIOIMMUNOASSAYS OF TETRAHYDROCORTISONE AND TETRAHYDROCORTISOL IN HUMAN URINE

1977 ◽  
Vol 86 (2) ◽  
pp. 369-379 ◽  
Author(s):  
H. Will ◽  
R. Aderjan ◽  
Th. Winkler ◽  
B. Penke ◽  
P. Vecsei
Keyword(s):  
New Zealand ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Human Urine ◽  
Bovine Serum ◽  
Secretion Rate ◽  
Cortisol Secretion ◽  
Cross Reactions ◽  
New Zealand Rabbits

ABSTRACT A simple radioimmunoassay for the determination of tetrahydrocortisone (THE)1), and tetrahydrocortisol (THF) as well as their 21-glucosiduronate conjugates is described. White New Zealand rabbits were immunized with THF- and THE-20-oxime-bovine serum-albumin conjugates. The resulting antisera proved to be very specific. Both allo-THE and allo-THF gave minimal cross-reactions; however, THE- and THF-21-glucosiduronate bind with the corresponding antibodies at a level of 100 %. The following types of estimations were introduced: a) Estimation of the sum of unconjugated THF and THF-21-glucosiduronate in highly diluted unprocessed human urine. b) A similar estimation of THE and THF-21-glucosiduronate as in a). c) Estimation of THF after β-glucuronidase treatment and dilution without further procedures. d) A similar estimation for THE as in c). THF and THE values correlate significantly with known parameters that characterize the cortisol production, such as cortisol secretion rate and the urinary corticoid (C21-α-ketolic-steroid) levels.

scholarly journals Evidence for the reversibility of the acyl-CoA:lysophosphatidylcholine acyltransferase in microsomal preparations from developing safflower (Carthamus tinctorius L.) cotyledons and rat liver

1984 ◽  
Vol 223 (2) ◽  
pp. 305-314 ◽  
Author(s):  
S Stymne ◽  
A K Stobart
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Rat Liver ◽  
Bovine Serum ◽  
Exchange Process ◽  
High Specificity ◽  
Carthamus Tinctorius ◽  
Back Reaction ◽  
Acyl Exchange ◽  
Rate Limiting Step

Acyl exchange between acyl-CoA and position 2 of sn-phosphatidylcholine occurs in the microsomal preparations of developing safflower cotyledons. Evidence is presented to show that the acyl exchange is catalysed by the combined back and forward reactions of an acyl-CoA:lysophosphatidylcholine acyltransferase (EC 2.3.1.23). The back reaction of the enzyme was demonstrated by the stimulation of the acyl exchange with free CoA and by the observation that the added CoA was acylated with acyl groups from position 2 of sn-phosphatidylcholine. Re-acylation of the, endogenously produced, lysophosphatidylcholine with added acyl-CoA occurred with the same specificity as that observed with added palmitoyl lysophosphatidylcholine. A similar acyl exchange, catalysed by an acyl-CoA:lysophosphatidylcholine acyltransferase, occurred in microsomal preparations of rat liver. The enzyme from safflower had a high specificity for oleate and linoleate, whereas arachidonate was the preferred acyl group in the rat liver microsomal preparations. The rate of the back reaction was 3-5% and 0.2-0.4% of the forward reaction in the microsomal preparations of safflower and rat liver respectively. Previous observations, that the acyl exchange in safflower microsomal preparations was stimulated by bovine serum albumin and sn-glycerol 3-phosphate, can now be explained by the lowered acyl-CoA concentrations in the incubation mixture with albumin and in the increase in free CoA in the presence of sn-glycerol 3-phosphate (by rapid acylation of sn-glycerol 3-phosphate with acyl groups from acyl-CoA to yield phosphatidic acid). Bovine serum albumin and sn-glycerol 3-phosphate, therefore, shift the equilibrium in acyl-CoA:lysophosphatidylcholine acyltransferase-catalysed reactions towards the rate-limiting step in the acyl exchange process, namely the removal of acyl groups from phosphatidylcholine. The possible role of the acyl exchange in the transfer of acyl groups between complex lipids is discussed.

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.

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