BOVINE PLASMA OESTROGENS, PROGESTERONE AND GLUCOCORTICOIDS DURING DEXAMETHASONE INDUCED PARTURITION

1976 ◽  
Vol 81 (2) ◽  
pp. 385-397 ◽  
Author(s):  
L. E. Evans ◽  
W. C. Wagner
Keyword(s):  
Protein Binding ◽  
Plasma Samples ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Progesterone Production ◽  
Bovine Plasma ◽  
Competitive Protein Binding ◽  
Pre Treatment

ABSTRACT Plasma samples were collected from jugular, uterine and utero-ovarian veins during glucocorticoid induced parturition. Plasma oestrogens, corticosteroids and progesterone were determined by competitive protein binding methods. Corticosteroids and progesterone began to decline within 8 to 10 h following DXMS treatment. Corticoids were only temporarily suppressed, while progesterone fell to minimum levels and remained low through calving. At this stage of gestation (270 days) peripheral plasma progesterone was primarily of ovarian origin. Pre-treatment with HCG appeared to support progesterone production by the CL despite DXMS treatment in 2 of 6 cows. These 2 cows failed to calve within the expected 96 h after DXMS. Plasma oestrogens did not show significant increases until 24 h after DXMS treatment. Cows which responded to DXMS treatment (calved) had significantly higher oestrogen levels than those which did not respond. It was concluded that oestrogens probably play a permissive rather than an initiating role in parturition.

scholarly journals Selected Factors that Affect the Measurement of Plasma Progesterone Concentrations in Pregnant Ewes

1974 ◽  
Vol 27 (6) ◽  
pp. 659 ◽  
Author(s):  
AR Gleeson ◽  
GD Thorburn
Keyword(s):  
Protein Binding ◽  
Diurnal Variation ◽  
Significant Positive Correlation ◽  
Plasma Samples ◽  
Elevated Plasma ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Peripheral Plasma ◽  
Competitive Protein Binding

A competitive protein-binding technique was used to measure progesterone concentrations in the peripheral plasma of pregnant ewes. Neither haemolysis of blood nor thawing of plasma samples affected plasma progesterone concentration. Blood samples should be chilled immediately upon collection but subsequent to centrifugation immediate chilling of the plasma samples is not critical. No consistent diurnal variation in progesterone concentrations was evident but there was large apparently random day-to-day variation in progesterone concentrations for any ewe. Although a significant positive correlation was found between endogenous progesterone and corticosteroid concentrations, the present study failed to correlate experimentally elevated plasma corticosteroid concentrations with progesterone concentrations. Progesterone concentrations varied greatly between ewes at the same stage of pregnancy.

THE SITE OF PROGESTERONE PRODUCTION IN EARLY PREGNANCY

1971 ◽  
Vol 67 (2) ◽  
pp. 353-361 ◽  
Author(s):  
Tore H:son Holmdahl ◽  
Elof D. B. Johansson ◽  
Leif Wide
Keyword(s):  
Protein Binding ◽  
Corpus Luteum ◽  
Early Pregnancy ◽  
Plasma Levels ◽  
Disappearance Rate ◽  
Plasma Progesterone ◽  
Progesterone Production ◽  
Vacuum Aspiration ◽  
Competitive Protein Binding

ABSTRACT The disappearance of progesterone* and HCG from the plasma was measured following therapeutic abortions in 17 patients from the seventh to the sixteenth week of pregnancy. Between the seventh and the twelfth week of gestation the evacuation of the uterine contents was performed by vacuum aspiration, and from the thirteenth week onwards abdominal hysterotomy was performed. Plasma progesterone was assayed using a competitive protein binding technique, while plasma HCG was determined by a radioimmunosorbent assay. After the evacuation of the uterine contents in the early pregnancy cases (weeks 7–8) the plasma levels of progesterone remained elevated much longer than in the later stages of pregnancy (weeks 12–16), thus suggesting that the corpus luteum graviditatis was the main source of progesterone in the first group, while in the last group the placenta was the main source of progesterone production. When comparing the earlier and later cases of pregnancy, the disappearance rate of plasma HCG remained essentially unaltered. From the results obtained, it seems likely that the transition from the ovarian to the placental production of progesterone occurs during the ninth to eleventh weeks of pregnancy.

Competitive protein-binding analysis of ovine and bovine plasma progesterone

Reproduction ◽  
1972 ◽  
Vol 28 (1) ◽  
pp. 148-150 ◽  
Author(s):  
M. Cain ◽  
J. Cerini ◽  
M. Cerini ◽  
W. Chamley ◽  
I. Cumming ◽  
...  
Keyword(s):  
Protein Binding ◽  
Plasma Progesterone ◽  
Binding Analysis ◽  
Bovine Plasma ◽  
Competitive Protein Binding

A COMPARISON OF THE COMPETITIVE PROTEIN-BINDING ASSAY AND RADIOIMMUNOASSAY FOR PLASMA PROGESTERONE DURING THE NORMAL MENSTRUAL CYCLE

1972 ◽  
Vol 54 (3) ◽  
pp. 445-456 ◽  
Author(s):  
CHRISTINE A. MORGAN ◽  
I. D. COOKE
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Protein Binding ◽  
Bovine Serum ◽  
Binding Assay ◽  
Plasma Samples ◽  
Plasma Progesterone ◽  
Protein Binding Assay ◽  
Competitive Protein Binding ◽  
Free Steroid

SUMMARY A protein-binding assay for plasma progesterone using 2% aqueous chick plasma as the binding solution is described. Details of specifications for petroleum spirit to extract the plasma are given, no chromatographic step being employed. Bound and free steroid are separated by Florisil. The system will assay plasma progesterone at a concentration of 2·0 ng/ml; other reliability data are evaluated. One technician can assay 12 duplicate plasma samples per day. The radioimmunoassay method has utilized two antisera, the first, antiprogesterone-20-0-carboxymethyl-oxime—bovine serum albumin at a dilution of 1 in 3000, the second, anti-progesterone-11-succinyl—bovine serum albumin at a dilution of 1 in 10000. Bound and free steroid are separated by dextran—charcoal suspension. The system will assay plasma progesterone at a concentration of 1·0 ng/ml. One technician can assay 24 duplicate plasma samples per day. There is a good correlation between results obtained by both competitive protein-binding (CPB) and radioimmunoassay (RIA) methods. Both methods have a place in estimating the large numbers of serial samples required in the study of physiological situations, although the RIA method will probably supersede the CPB because of its robustness and greater output.

AN IMPROVED METHOD FOR THE ASSAY OF PROGESTERONE BY COMPETITIVE PROTEIN BINDING

1970 ◽  
Vol 63 (2) ◽  
pp. 225-241 ◽  
Author(s):  
B. D. Reeves ◽  
M. L. A. de Souza ◽  
I. E. Thompson ◽  
E. Diczfalusy
Keyword(s):  
Protein Binding ◽  
Binding Sites ◽  
Entire Range ◽  
Improved Method ◽  
Plasma Progesterone ◽  
Extraction And Purification ◽  
Corticosteroid Binding Globulin ◽  
Competitive Protein Binding ◽  
The Individual ◽  
Range Of Values

ABSTRACT An improved method for the assay of plasma progesterone by competitive protein binding is described. The improvement is based upon rigorous control of the variables, the compensation for and standardisation of interfering factors inherent in the method and the use of a human corticosteroid binding globulin, that meets the requirements for sensitivity at levels of 1.0 ng of progesterone and below. The assessment of the reliability of the individual steps in the method as well as that of the complete method is presented. The sensitivity of the method is around 0.2 ng progesterone per ml plasma. Accuracy was measured by adding progesterone in amounts ranging from 0.0 to 1.0 ng to 1.0 ml plasma. There was a linear relationship between the progesterone added and recovered throughout the entire range of values, with a coefficient of correlation (r) of 0.94. Of 52 related steroids tested, none was found which would remain associated with progesterone following extraction and purification and which would also compete with progesterone for binding sites.

EVALUATION OF A RAPID METHOD FOR THE MEASUREMENT OF PLASMA PROGESTERONE BY COMPETITIVE PROTEIN BINDING

1970 ◽  
Vol 46 (3) ◽  
pp. 369-377 ◽  
Author(s):  
B. T. MARTIN ◽  
B. A. COOKE ◽  
W. P. BLACK
Keyword(s):  
Menstrual Cycle ◽  
Protein Binding ◽  
Ethyl Acetate ◽  
Rapid Method ◽  
Chromatographic Separation ◽  
Good Accuracy ◽  
Human Subjects ◽  
Plasma Progesterone ◽  
Competitive Protein Binding ◽  
Paper Chromatographic Separation

SUMMARY A competitive protein-binding method for the measurement of progesterone in plasma of human subjects was investigated. The purification steps necessary to achieve good accuracy, precision and specificity were determined. It was found that one paper chromatographic separation of unwashed ethyl acetate plasma extracts was sufficient, providing that the sample contains a minimum of 1 ng. progesterone. Water blank values equivalent to 0·05 ng. progesterone were consistently obtained. The concentrations of progesterone found in plasma during the follicular and luteal phases of the menstrual cycle and in male plasma were 0·14 ± 0·14, 0·82 ± 0·74 and 0·022 ± 0·015 (s.d.) μg./100 ml., respectively.

A SIMPLIFIED PROCEDURE FOR THE ASSAY OF PROGESTERONE

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S188-S203 ◽  
Author(s):  
Elof D. B. Johansson
Keyword(s):  
Protein Binding ◽  
Petroleum Ether ◽  
Luteal Phase ◽  
Plasma Progesterone ◽  
Ether Extraction ◽  
Competitive Protein Binding ◽  
One Year ◽  
Simplified Procedure ◽  
Layer Chromatography

ABSTRACT During one year 8000 determinations of plasma progesterone have been made, using a simple petroleum ether extraction of the plasma followed by competitive protein binding analysis. The selection of the petroleum ether is crucial for the specificity, which is acceptable for the determination of progesterone during the luteal phase of the menstrual cycle and during pregnancy. The limit of sensitivity is 0.1 ng. Only 0.25 ml of plasma is needed for the determination during the luteal phase and 0.05 to 0.10 ml during pregnancy. One technician can assay 20 samples in one day with good accuracy and a precision of 7.9 per cent in the most favourable range of measurements. In research projects involving drugs the influence of these drugs on the competitive protein binding system has to be tested. Some of the samples should be further purified by thin layer chromatography as a constant check on the specificity for progesterone.

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