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.

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.

THE CONCENTRATION OF PROGESTERONE IN THE PERIPHERAL PLASMA OF THE PREGNANT EWE

1969 ◽  
Vol 45 (3) ◽  
pp. 449-457 ◽  
Author(s):  
J. M. BASSETT ◽  
TANA J. OXBORROW ◽  
I. D. SMITH ◽  
G. D. THORBURN
Keyword(s):  
Protein Binding ◽  
Early Pregnancy ◽  
Luteal Phase ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
High Concentrations ◽  
Pregnant Ewe

SUMMARY The progesterone concentration in the peripheral plasma of ewes throughout pregnancy has been determined by a protein-binding method. Plasma progesterone concentrations during the first 50 days of pregnancy (2–3 ng./ml.) were not significantly higher than peak concentrations during the luteal phase in cycling non-pregnant ewes, but there was no decrease in the concentration 15–20 days after mating as occurs in non-pregnant ewes. Between 50 and 120 days after mating the plasma progesterone concentration increased steadily to values 2–5 times that found in early pregnancy. These high concentrations were maintained until lambing. A decrease in progesterone concentration during the week preceding lambing was usually, but not always, observed. Mean plasma progesterone concentrations during the last 50 days of pregnancy in ewes with twins were approximately twice those in ewes with a single foetus.

Peripheral plasma progesterone and oestradiol concentrations associated with successful and unsuccessful recovery of uterine embryos in rhesus monkeys with and without intra-uterine devices

1983 ◽  
Vol 96 (2) ◽  
pp. 281-286
Author(s):  
A. G. Wheeler ◽  
P. R. Hurst ◽  
P. Eckstein
Keyword(s):  
Menstrual Cycle ◽  
Success Rate ◽  
Rhesus Monkeys ◽  
Plasma Samples ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Uterine Lumen ◽  
Peripheral Plasma ◽  
Embryo Transport

Concentrations of progesterone and oestradiol were measured in peripheral plasma samples collected at the time when the uteri of rhesus monkeys with an intra-uterine device (IUD) and those without an IUD were flushed in attempts to recover uterine embryos. The proportion of successful attempts in IUD-bearing monkeys was much lower than in the non-IUD-bearing animals. Steroid measurements indicated that this reduced success rate was not due to an effect of the IUD on the timing of ovulation within the menstrual cycle or to a steroid-mediated disturbance in the rate of embryo transport to the uterine lumen. Successful embryo recoveries were associated with a higher progesterone concentration, suggesting that one reason for failure was that the attempt had been made too close to ovulation. There was no evidence of any asymmetry between the left or right ovaries in their ovulatory or steroidogenic activity.

PERIPHERAL PLASMA PROGESTERONE CONCENTRATIONS IN SHEEP DURING THE OESTROUS CYCLE

1973 ◽  
Vol 58 (2) ◽  
pp. 219-225 ◽  
Author(s):  
K. P. McNATTY ◽  
K. J. A. REVFEIM ◽  
A. YOUNG
Keyword(s):  
Luteal Phase ◽  
Oestrous Cycle ◽  
Diurnal Changes ◽  
Progesterone Concentration ◽  
Once Daily ◽  
Plasma Progesterone ◽  
Blood Samples ◽  
Peripheral Plasma ◽  
The Hours

SUMMARY Progesterone concentrations in peripheral plasma were measured once daily during one oestrous cycle in each of eight sheep. In addition, on days 4–5, 8–9, 12–13 and 15–16 of the oestrous cycle, blood samples were collected at 30-min intervals throughout each 24-h period. A total of three ewes was sampled in each 24-h period and the same three animals were not bled again for at least 1 week. Plasma progesterone concentrations in all the ewes fluctuated considerably throughout each 24-h period. The within-sheep within-day variations observed in peripheral progesterone concentrations were compared with the between-sheep within-day variations and the within-sheep between-day variations previously reported. It is concluded that these previously reported variations in peripheral plasma progesterone concentration could be attributed to within-day variations in each animal. On days 8–9 and 12–13 of the oestrous cycle there were significantly higher concentrations of progesterone in plasma during the hours of daylight than during the hours of darkness. In contrast, progesterone concentrations on days 4–5 and 15–16 were not found to be significantly different between the hours of daylight and darkness. These results suggest that diurnal changes in peripheral plasma progesterone concentration occur during the luteal phase of the ovine oestrous cycle.

PLASMA PROGESTERONE LEVELS IN GOATS DURING PREGNANCY MEASURED BY COMPETITIVE PROTEIN BINDING

1971 ◽  
Vol 66 (3) ◽  
pp. 471-477 ◽  
Author(s):  
Anne Kristine Blom ◽  
Olav Lyngset
Keyword(s):  
Protein Binding ◽  
Uterine Artery ◽  
Venous Blood ◽  
Ovarian Vein ◽  
Progesterone Concentration ◽  
Gradual Decline ◽  
Plasma Progesterone ◽  
Peripheral Venous Blood ◽  
Before And After ◽  
Competitive Protein Binding

ABSTRACT Plasma progesterone concentration at different stages of pregnancy was measured in the blood obtained from the uterine artery (6 goats), the uterine vein (6 goats), and the ovarian vein (11 goats). Progesterone concentration was also measured in the peripheral venous blood before and after extirpation of the ovaries and the uterus (16 goats). The concentration of progesterone was found to rise gradually in the peripheral and ovarian vein blood to reach a maximum at 90 days of pregnancy. This was followed by a gradual decline with consistent low values of about 7 ng prog./ml 3–4 days before parturition. A significant decrease in peripheral progesterone concentration was found 10 minutes after removing the ovaries and the uterus. In two goats sampled before and after parturition, the plasma progesterone concentration was found to decrease before parturition and to remain low for at least three days after parturition.

PROGESTERONE CONCENTRATION IN THE PERIPHERAL PLASMA OF PREGNANT GOATS

1972 ◽  
Vol 53 (3) ◽  
pp. 447-452 ◽  
Author(s):  
G. IRVING ◽  
D. E. JONES ◽  
A. KNIFTON
Keyword(s):  
Cord Blood ◽  
Venous Blood ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Significant Difference ◽  
Competitive Protein Binding ◽  
The Mean ◽  
Serial Samples ◽  
Twin Pregnancies

SUMMARY Plasma progesterone concentration was measured by a competitive protein-binding method in serial samples of jugular venous blood from 21 pregnant goats, 11 with twin and 10 with single foetuses. Progesterone levels in twin pregnancies were significantly greater than in singletons. The mean progesterone concentration (ng/ml plasma) in the twin pregnancies was greatest during the 3rd month of gestation (10·7 ± 0·4 (s.e.m.)) and in the singletons during the 4th month (7·8 ± 0·2 (s.e.m.)). There was a significant decrease in mean progesterone concentration in the last month of pregnancy due to a steady decline in the last 7 days before parturition. The mean progesterone concentrations at parturition in five twin and eight single pregnancies were 2·2 ± 0·4 and 1·5 ± 0·2 (s.e.m.) ng/ml plasma respectively; there was no significant difference between these values. In cord blood from nine kids immediately after delivery the progesterone concentration was 0·9 ± 0·1 ng/ml.

scholarly journals Assessment of a Simple Competitive Protein-Binding Technique for Plasma Cortisol Assay

1975 ◽  
Vol 12 (1-6) ◽  
pp. 66-69 ◽  
Author(s):  
Mary F. Crowley ◽  
Katherine J. T. Garbien ◽  
J. W. Tuttlebee
Keyword(s):  
Protein Binding ◽  
Plasma Cortisol ◽  
Late Pregnancy ◽  
Plasma Samples ◽  
Blood Samples ◽  
Prednisolone Therapy ◽  
Dexamethasone Therapy ◽  
Competitive Protein Binding ◽  
Synthetic Steroids ◽  
Significant Interference

The Cortipac kit for Cortisol assay by a competitive protein-binding technique (CPB) which utilizes 75Se Cortisol has been evaluated. Results obtained by it agree well with those by the Mattingly fluorimetric method. Assays can be carried out on either plasma or serum and haemolysis does not interfere. The specificity of the assay was checked in blood samples from patients receiving synthetic steroids. Prednisone and prednisolone therapy caused significant interference with the assay; fluorocortisol and dexamethasone therapy did not. The increased progesterone in late pregnancy blood samples had only a small effect on the assay. Plasma samples for Cortisol assay could be stored for at least 4 weeks at 4°C and for at least 12 weeks at −20°C.

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.

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