THE PROGESTERONE CONCENTRATION IN THE PLASMA OF THE GOAT DURING THE OESTROUS CYCLE AND PREGNANCY

1972 ◽  
Vol 52 (1) ◽  
pp. 23-36 ◽  
Author(s):  
G. D. THORBURN ◽  
W. SCHNEIDER

SUMMARY Progesterone concentrations in the peripheral plasma of goats were measured by a protein-binding assay. The mean concentration was extremely low on the day of oestrus (0·2 ng/ml) and was not significantly different from that found in anoestrous or ovariectomized animals. The concentration increased to a maximum of 4 ng/ml on about day 10 of the 21-day cycle, and decreased rapidly during the last 3 days of the cycle. Plasma progesterone concentration during early pregnancy (2·5–3·5 ng/ml) was similar to the luteal phase value and remained steady from day 8 to day 60. Between days 60 and 70 there was a secondary increase in progesterone concentration which was maintained at this increased level (4·5–5·5 ng/ml) until just before parturition. In twin-bearing animals, the secondary increase was greater. Progesterone concentration decreased rapidly during the 1–2 days preceding parturition, but the concentration was still quite high on the day of parturition (1·25 ng/ml). The progesterone concentration in peripheral plasma was markedly increased during anaesthesia and the operation. After bilateral ovariectomy of the pregnant goat, peripheral progesterone concentration fell rapidly from 9 to 2·5 ng/ml during the first ½ h and then more slowly during the next 5–6 h. The animals aborted 36–48 h later. A consistent positive arterio—venous difference for progesterone was observed across the pregnant uterus in two unanaesthetized goats. These results indicate that the ovary is the main site of progesterone production in the pregnant goat and that production by the placenta is small and unlikely to influence the level of this hormone in the maternal circulation.

1967 ◽  
Vol 55 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Benno Runnebaum ◽  
Josef Zander

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.


1971 ◽  
Vol 49 (5) ◽  
pp. 599-604 ◽  
Author(s):  
A. J. Peterson ◽  
R. H. Common

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.


1972 ◽  
Vol 53 (3) ◽  
pp. 447-452 ◽  
Author(s):  
G. IRVING ◽  
D. E. JONES ◽  
A. KNIFTON

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.


1973 ◽  
Vol 59 (3) ◽  
pp. 429-438 ◽  
Author(s):  
O. M. MØLLER

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.


1971 ◽  
Vol 68 (3) ◽  
pp. 543-550 ◽  
Author(s):  
D. W. Christie ◽  
E. T. Bell ◽  
C. E. Horth ◽  
R. F. Palmer

ABSTRACT Plasma progesterone levels were determined in 16 Beagle bitches undergoing a normal oestrous cycle. The mean concentration rose during oestrus and a peak of 20.3 ng/ml was attained early in metoestrus. Considerable variation was noted between animals in respect of the magnitude and timing of the progesterone peak. The time of the highest progesterone values ranged from three days before the end of oestrus to Day 21 of metoestrus. The mean hormone levels remained elevated throughout metoestrus. On the basis of the time of the initial rise in progesterone levels during oestrus and the oestrogen peak values in three animals, it is suggested that ovulation occurs on the first or second day of oestrus.


1970 ◽  
Vol 48 (4) ◽  
pp. 599-614 ◽  
Author(s):  
L. E. DONALDSON ◽  
J. M. BASSETT ◽  
G. D. THORBURN

SUMMARY Progesterone concentrations in the peripheral plasma of cows were measured by a protein-binding radioassay method. The mean concentration was lowest at oestrus (0·44 ng/ml) and then increased to a maximum of 6·8 ng/ml about day 14 of the 21-day cycle. The concentration decreased rapidly during the last 4 days of the cycle, reaching low levels on the day before oestrus. There were no significant changes in progesterone concentration during oestrus. After ovariectomy the plasma progesterone concentration decreased to a very low level (< 0·4 ng/ml). After hysterectomy, progesterone concentrations remained high for longer than in a normal cycle. At puberty, plasma progesterone concentrations indicated cyclic ovarian activity before the first observed oestrus. Daily treatment of cows with oxytocin (0·4 u./kg body weight) from day 2 reduced the oestrous cycle length to 9 days, but did not significantly alter the slow increase in plasma progesterone concentration during the first 5 days of the cycle. Plasma progesterone concentrations decreased again after day 5 to low values. Plasma progesterone concentration during early pregnancy was similar to the luteal phase value (4–6 ng/ml), declined during mid-pregnancy and then increased to a maximum (7–8 ng/ml) at about 240 days gestation. The concentration declined 2–3 weeks before calving. During lactation progesterone concentrations were very low until the resumption of cyclic ovarian activity. The first post-partum cycle, whether accompanied by observed oestrus or not, was usually preceded by a small increase in plasma progesterone concentration 3–5 days before the start of the cycle. Undernutrition significantly increased plasma progesterone concentrations in mid- and late pregnancy. Undernutrition of non-pregnant cows increased progesterone concentrations during the luteal phase of the first cycle, but reduced it in later cycles.


1974 ◽  
Vol 46 (2) ◽  
pp. 231-240 ◽  
Author(s):  
S. Edelstein ◽  
M. Charman ◽  
D. E. M. Lawson ◽  
E. Kodicek

1. A competitive protein-binding assay for plasma 25-hydroxycholecalciferol was developed, using Sephadex LH-20 columns for the isolation of the sterol and a partially purified protein from rat serum as the binding protein. 2. The mean plasma 25-hydroxycholecalciferol in eighteen male and female normal volunteers was 38 ± SD 14 pmol/ml (15–2 ± 5–6 ng/ml). 3. Levels of 25-hydroxycholecalciferol in plasma of four male volunteers maintained for 2 months on a diet supplemented with 26·1 nmol (10 μg) of cholecalciferol a day were found to be significantly higher. 4. High correlation was established between plasma 25-hydroxycholecalciferol values obtained by the competitive protein-binding assay and values obtained by bioassay.


1963 ◽  
Vol 26 (1) ◽  
pp. 65-73 ◽  
Author(s):  
M. G. BRUSH

SUMMARY Plasma levels of progesterone and 20 α-hydroxypregn-4-en-3-one have been studied after intravenous (i.v.) and intramuscular (i.m.) injections of progesterone in sheep. I.v. injected progesterone was removed from the bloodstream very rapidly and it was necessary to give 50 mg. before it was possible to detect progesterone at times up to 10 min. after the injection. With 100 mg. amounts of progesterone injected i.v. the mean concentration in samples taken up to 10 min. after the injection was 34·7 μg./100 ml. plasma (range 4–110 μg./100 ml. in 9 samples), but after 1 hr. the mean level was 2·2 μg./100 ml. plasma (range 0–10 μg./100 ml. in 10 samples). The concentrations of 20 α-hydroxypregn-4-en-3-one were usually, but not always, less than those of progesterone. When progesterone was given by i.m. injection it was not possible to establish detectable blood levels. The effect of the injection vehicle was also studied for each injection route. Some new modifications of Short's method (1958) for the determination of plasma progesterone are described and discussed.


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