Progesterone concentration in peripheral plasma of laying hens as determined by competitive protein-binding assay

The concentration of progesterone in the peripheral blood plasma of laying hens attained a peak value 4–6 h before ovulation. A peak value was not observed on days where ovulation did not occur, i.e., on days when the terminal egg of a sequence was laid.For nine ovulatory cycles the average level was 2.45 ng/ml with a range of 0.5 to 8.8 ng/ml. For five periods covering a day of no ovulation the average was 2.95 ng/ml with a range of 0.5 to 12.5 ng/ml.

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A COMPETITIVE PROTEIN-BINDING ASSAY FOR TESTOSTERONE IN THE PLASMA OF THE BULL AND THE RAM

Journal of Endocrinology ◽

10.1677/joe.0.0510303 ◽

1971 ◽

Vol 51 (2) ◽

pp. 303-312 ◽

Cited By ~ 3

Author(s):

C. B. KATONGOLE

Keyword(s):

Protein Binding ◽

Binding Assay ◽

Late Pregnancy ◽

Chromatographic Technique ◽

Peripheral Plasma ◽

Protein Binding Assay ◽

Peripheral Blood Plasma ◽

Competitive Protein Binding Assay ◽

Competitive Protein Binding ◽

High Degree

SUMMARY A method is described for the measurement of testosterone in peripheral blood plasma by competitive protein binding, using a 1:80 dilution of human late-pregnancy plasma and Sephadex for separating protein-bound from unbound steroid. The reliability criteria were examined in detail for plasma from bulls and rams. Testosterone was measured with a high degree of accuracy, and with a precision of 4·9–7·9% in the concentration range of 4–24 ng/ml. The specificity of the method was checked by comparing it with a gas-chromatographic technique, and the agreement was good. The testosterone concentrations in the peripheral plasma of bulls and rams were found to range between 2 and 24 ng/ml.

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Competitive Protein-Binding Assay for Corticoids in the Peripheral Plasma of the Immature Chicken

Poultry Science ◽

10.3382/ps.0530241 ◽

1974 ◽

Vol 53 (1) ◽

pp. 241-245 ◽

Cited By ~ 30

Author(s):

R.B. Buckland ◽

K. Blagrave ◽

P.C. Laguë

Keyword(s):

Protein Binding ◽

Binding Assay ◽

Peripheral Plasma ◽

Protein Binding Assay ◽

Competitive Protein Binding Assay ◽

Competitive Protein Binding

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HORMONAL REQUIREMENTS FOR THE MAINTENANCE OF LUTEAL FUNCTION IN HYPOPHYSECTOMIZED, PSEUDOPREGNANT RATS

Journal of Endocrinology ◽

10.1677/joe.0.0560421 ◽

1973 ◽

Vol 56 (3) ◽

pp. 421-429 ◽

Cited By ~ 12

Author(s):

MASAOMI TAKAYAMA ◽

G. S. GREENWALD

Keyword(s):

Plasma Levels ◽

Binding Assay ◽

Follicle Stimulating Hormone ◽

Luteal Function ◽

Peripheral Plasma ◽

Protein Binding Assay ◽

Competitive Protein Binding Assay ◽

Competitive Protein Binding ◽

Higher Doses

SUMMARY Pseudopregnant rats with traumatized uteri were hypophysectomized on day 6 and injected with various hormones over the next 4 days. Luteal function was assessed on day 10 of pseudopregnancy by weighing deciduomata and determining luteal and plasma levels of progesterone by a competitive protein-binding assay. Daily treatment with 0·25 mg prolactin restored plasma and luteal levels to the values of intact pseudopregnant animals; however, the deciduomata weighed only 55% of control values. Combining oestrone with prolactin restored deciduomata weight to control values without affecting peripheral progesterone levels. Either 200 μg of follicle-stimulating hormone (FSH) or 5 μg luteinizing hormone (LH) could be substituted for oestrone, in conjunction with prolactin, to increase deciduomata weight to control values. Moreover, the combination of prolactin with FSH or LH significantly increased peripheral plasma levels of progesterone beyond the effects of prolactin alone. Higher doses of LH were luteolytic as shown by decreased deciduomata weight and considerable variation in plasma and luteal values of progesterone. LH given alone — either in saline or polyvinyl pyrrolidine — failed to maintain any of the parameters of luteal activity mentioned above. The results reaffirm the primacy of prolactin in vivo as the principal luteotrophic hormone of the rat and indicate that selected doses of LH or FSH play an additive role in further increasing peripheral levels of progesterone.

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PROGESTERONE CONCENTRATIONS IN THE PERIPHERAL PLASMA OF THE BLUE FOX (ALOPEX LAGOPUS) DURING PREGNANCY AND THE OESTROUS CYCLE

Journal of Endocrinology ◽

10.1677/joe.0.0590429 ◽

1973 ◽

Vol 59 (3) ◽

pp. 429-438 ◽

Cited By ~ 27

Author(s):

O. M. MØLLER

Keyword(s):

Binding Assay ◽

Post Partum ◽

Progesterone Level ◽

Alopex Lagopus ◽

Plasma Progesterone ◽

Peripheral Plasma ◽

Protein Binding Assay ◽

Competitive Protein Binding Assay ◽

Competitive Protein Binding ◽

Blue Fox

SUMMARY A competitive protein-binding assay was evaluated and employed in the measurement of progesterone in serial plasma samples obtained from pregnant, non-pregnant and non-receptive blue-fox vixens. At the beginning of the period of pro-oestrous vulval swelling, the plasma progesterone concentration was always found to be below 2 ng/ml. Towards the end of pro-oestrus and during the period of oestrus (sexual receptivity) the concentration increased rather quickly. On the 3rd and the 4th days of oestrus, i.e. when most of the vixens were mated, the plasma progesterone concentrations were about 30 ng/ml (range: 18–36 ng/ml). During gestation (53 or 54 days) the plasma progesterone level rose very steeply and attained a maximum plateau (> 80 ng/ml) between days 5 and 8 post coitum, remained high until about day 20, but thereafter fell rather quickly to below 30 ng/ml between days 35 and 40. Later on the progesterone level fell gradually to below 5 ng/ml at the day of parturition, and, 4 days post partum and later, the levels were below the limit of the sensitivity of the assay used (< 2 ng/ml). The progesterone values and profiles obtained from the non-pregnant vixens (mated vixens which failed to whelp) corresponded clearly to those obtained in the pregnant vixens. Indeed, even in two non-receptive vixens (unwilling to mate during the mating season) typical progesterone profiles were obtained during a period of about 70 days.

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OESTRADIOL LEVELS IN THE PERIPHERAL BLOOD OF COWS DURING THE OESTROUS CYCLE

Journal of Endocrinology ◽

10.1677/joe.0.0550073 ◽

1972 ◽

Vol 55 (1) ◽

pp. 73-78 ◽

Cited By ~ 27

Author(s):

M. SHEMESH ◽

N. AYALON ◽

H. R. LINDNER

Keyword(s):

Oestrous Cycle ◽

Published Data ◽

Chromatographic Purification ◽

Peripheral Plasma ◽

Protein Binding Assay ◽

Competitive Protein Binding Assay ◽

Competitive Protein Binding ◽

A Minor ◽

Peak Value ◽

Sustained Increase

SUMMARY Changes in the peripheral plasma level of oestradiol during the bovine oestrous cycle were determined by a competitive protein-binding assay, following chromatographic purification of the steroid. Oestradiol concentration increased during the 3 days preceding oestrus and attained its peak value [17 ± 1·9 (s.e.m.) ng/100 ml] 4 h before oestrous behaviour could be detected. The level declined steeply during the day of oestrus to reach a nadir (0·8 ± 0·11) before the time of ovulation. A minor rise was observed on day 4 and a more sustained increase on days 10–13, with a peak on day 11 (8·1 ± 3·6). Comparison with published data on luteinizing hormone (LH) levels suggests that the pre-oestrous surge of oestradiol precedes the pre-ovulatory surge of LH in the cow.

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TESTOSTERONE AND DIHYDROTESTOSTERONE CONCENTRATIONS IN THE FLUID MILIEU OF SPERMATOZOA IN THE REPRODUCTIVE TRACT OF THE BULL

Acta Endocrinologica ◽

10.1530/acta.0.0740186 ◽

1973 ◽

Vol 74 (1) ◽

pp. 186-200 ◽

Cited By ~ 17

Author(s):

Venkataseshu K. Ganjam ◽

Rupert P. Amann

Keyword(s):

Mass Spectrometry ◽

Seminal Plasma ◽

Reproductive Tract ◽

Binding Assay ◽

Rete Testis ◽

Protein Binding Assay ◽

Highly Sensitive ◽

Competitive Protein Binding Assay ◽

Competitive Protein Binding ◽

Isolated Compound

ABSTRACT Total 17β-hydroxyandrogen concentrations were determined using a competitive protein binding assay, for bovine reproductive fluids. Rete testis fluid and cauda epididymal plasma were separated from the spermcontaining fluids obtained through cannulae from conscious bulls. Al-through the concentration of total 17β-hydroxyandrogens in rete testis fluid was similar (P > 0.05) to that in cauda epididymal plasma (25 and 19 ng/ml), both fluids contained higher (P < 0.01) androgen concentrations than seminal plasma, accessory sex gland fluid or serum from peripheral blood (3–5 ng/ml). However, since the amount of cauda epididymal plasma recovered was much less than for rete testis fluid (0.25 vs 35 ml/day), cauda epididymal plasma contained less than 1 % of the total 17β-hydroxyandrogens which entered the epididymis in rete testis fluid (5 vs 883 ng/day). Testosterone and/or dihydrotestosterone were isolated from the reproductive fluids by Sephadex LH-20 chromatography and quantified by a simple, specific and highly sensitive microassay. Dihydrotestosterone was found only in cauda epididymal plasma (14 ng/ml); identification of the isolated compound was confirmed by mass spectrometry. Dihydrotestosterone accounted for 52% of the 17β-hydroxyandrogens in cauda epididymal plasma while 23 % was testosterone. Testosterone represented 70 % of the 17β-hydroxyandrogens in rete testis fluid and 91 % of those in blood serum. Physiological implications of this shift in androgen balance are discussed.

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