DIURNAL CHANGES IN THE CONCENTRATION OF PROGESTERONE IN THE PLASMA OF WOMEN AT 34–35 WEEKS OF GESTATION

1981 ◽  
Vol 89 (3) ◽  
pp. 337-341 ◽  
Author(s):  
J. R. G. CHALLIS ◽  
J. V. WORKEWYCH ◽  
J. E. PATRICK

The concentration of progesterone has been measured in ten women at 34–35 weeks of gestation in blood samples taken at 30 or 60 min intervals during a 24 h study period. Plasma progesterone concentrations showed a distinct diurnal rhythm. Most values determined between 04.00 and 11.00 h were significantly lower than the peak concentrations measured between 13.00 and 01.00 h. The relation of these changes in plasma progesterone to those in plasma cortisol and oestrogens is discussed.

1995 ◽  
Vol 75 (2) ◽  
pp. 197-201 ◽  
Author(s):  
C. Cooper ◽  
A. C. O. Evans ◽  
S. Cook ◽  
N. C. Rawlings

In evaluating stress in farm animals, it would be useful to know whether there were consistent endocrine responses that could be followed. Adrenal cortisol secretion is quite variable, but β-endorphin secretion and adrenal progesterone production may be useful indicators of stress. Changes in plasma concentrations of cortisol, β-endorphin and progesterone were studied in spring-born, castrated male calves (steers) (6 mo of age ± 18 d, 516 ± 26 kg, n = 12) subjected to the stress of routine dehorning. Steers were isolated from their dams for 2 h before headgate restraint (control) or restraint and dehorning. They were bled 60 and 10 min prior to headgate restraint or restraint and dehorning. Blood samples were also collected immediately after headgate restraint or restraint and dehorning (time 0) and 5, 10, 30 and 60 min later. All blood samples were taken from a jugular catheter, and the blood sampling that was done out of the headgate involved minimal manual restraint. Plasma β-endorphin concentrations were similar in control steers and dehorned steers (P > 0.05) and decreased significantly following restraint or restraint and dehorning (P < 0.05). Plasma cortisol concentrations rose significantly 5 min after dehorning and were elevated for 60 min; but with restraint only, plasma cortisol concentrations rose to a peak 5 min after release from chute restraint and then declined (P < 0.05). Plasma cortisol concentrations were greater in dehorned steers than in control steers in the period from 10 min after dehorning or headgate restraint to 60 min after headgate restraint (P < 0.0043). Plasma progesterone concentrations rose to a peak 10 min after dehorning and then declined, but in control steers, a peak was seen at 5 min after release from restraint (P < 0.05). Plasma progesterone concentrations were greater in dehorned steers between 5 and 60 min after dehorning than in control steers (P < 0.05). From these data, we concluded that in prepubertal, castrated male calves, β-endorphin was not released in any significant quantities in response to the stress of dehorning. In steers, adrenal cortisol and progesterone were secreted in response to acute stress, and a ratio of the two may provide a useful assessment of stress; this requires further study. Key words: Cortisol, progesterone, β-endorphin, stress, calves


1973 ◽  
Vol 58 (2) ◽  
pp. 219-225 ◽  
Author(s):  
K. P. McNATTY ◽  
K. J. A. REVFEIM ◽  
A. YOUNG

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.


1982 ◽  
Vol 100 (2) ◽  
pp. 279-284 ◽  
Author(s):  
R. C. Arora ◽  
R. S. Pandey

Abstract. Domestic buffaloes were used to characterize the pattern of progesterone, oestradiol-17β, LH and androgen in the systemic circulation following infertile insemination. Concentrations of hormones were measured by RIA in blood samples collected daily or at alternate days following insemination. The concentration of progesterone was lowest on the day of insemination, and increased significantly to a peak level of 4.00 ± 0.60 ng/ml by day 13 post insemination. After day 17, it declined significantly (P < 0.01) to reach low levels by day 21. The concentration of oestradiol-17β was high at the time of insemination and declined significantly (P < 0.01) by day 2 after insemination. It was maintained around the basal level till day 18 with minor peaks in between this period. It again rose significantly (P < 0.01) at subsequent oestrus. The mean level of LH was highest at the time of insemination, and declined significantly (P < 0.01) by day 1 post insemination. It did not vary appreciably till the animal returned to oestrus. The oestrous value of LH and progesterone were negatively correlated (r = −0.77). The androgen level was observed to be high at insemination in 3 out of 5 animals, but the overall pattern of this steroid was inconsistent during the period studied. A high concentration of androgen was recorded in all the animals from day 2–5 before the onset of oestrus.


1991 ◽  
Vol 130 (3) ◽  
pp. 457-462 ◽  
Author(s):  
S. C. Wilson ◽  
R. T. Gladwell ◽  
F. J. Cunningham

ABSTRACT Diurnal changes of LH secretion in sexually immature hens of 9, 11, 13 and 15 weeks of age consisted of 25–40% increases in the mean concentrations of LH in plasma between 15.00 and 18.00 h, i.e. between 2 h before and 1 h after the onset of darkness. During this time there was a tendency for the mean contents of LHRH-I in the anterior hypothalamus and posterior hypothalamus to increase by 21–74% and 20–56% respectively. In hens of 9 and 15 weeks, diurnal changes in the plasma concentration of LH closely paralleled those of LHRH-I content in the posterior hypothalamus. In contrast, the diurnal rhythm of LH secretion in hens of 11 and 13 weeks was more marked and plasma concentrations of LH continued to rise steeply between 18.00 and 21.00 h, i.e. between 1 and 4 h after the onset of darkness. At 11 weeks, this was associated with a reduction (P<0·01) in the contents of LHRH-I and LHRH-II, particularly in the anterior hypothalamus. In laying hens, a diurnal decline (P<0·01) in the plasma concentration of LH between 1 and 4 h after the onset of darkness was preceded by a fall (P<0·05) in the content of LHRH-I in the posterior hypothalamus and in the total hypothalamic content of LHRH-II (P<0·01). In all groups of hens, irrespective of the times of day at which tissue was taken, significant (P<0·05–<0·001) correlations between the contents of LHRH-I and LHRH-II in the anterior hypothalamus were observed. It is concluded that a diurnal rhythm of release of LHRH-I may drive the diurnal rhythm of LH secretion. Thus, in sexually immature hens of 9 and 15 weeks and laying hens in which diurnal changes in plasma LH were small there were parallel changes in the content of LHRH-I in the posterior hypothalamus. However, where the plasma concentration of LH was increased substantially, as at 11 weeks, there was a decline in the hypothalamic contents of LHRH-I. A simultaneous fall in the hypothalamic content of LHRH-II raises the possibility of a causal relationship between the activities of LHRH-II, LHRH-I and the release of LH. Journal of Endocrinology (1991) 130, 457–462


2000 ◽  
Vol 71 (2) ◽  
pp. 235-242 ◽  
Author(s):  
T. Tokuda ◽  
T. Matsui ◽  
H. Yano

AbstractPlasma leptin concentration shows pulsatility and diurnal rhythm in humans. However, there are few reports concerning the 24-h profile of circulating leptin levels in ruminants. Five crossbred ewes were housed in metabolism cages under a 1-h light-dark cycle. The ewes were offered alfalfa hay daily to meet their energy requirement. Blood samples were collected at 15-min intervals for 24 h. Plasma leptin concentrations were determined using a radioimmunoassay and the profile of plasma leptin levels was analysed by the PULSAR algorithmic program for detecting pulse. Plasma leptin concentration changed in a pulsatile fashion. The mean leptin concentration was 2·93 ng/ml. The mean pulse frequency was 4·8 pulses per day and the mean pulse amplitude was 0·67 ng/ml with an average pulse length of 1:13 h. Plasma leptin level was not affected by feeding or lighting cycle. These results indicate that plasma leptin level in sheep shows pulsatility but diurnal rhythm is not exhibited.


1984 ◽  
Vol 62 (6) ◽  
pp. 1095-1100 ◽  
Author(s):  
I. L. Boyd

Adult female grey seals were sampled at the Fame Islands at monthly intervals from November 1980 to October 1981. The distribution, size, and number of ovarian corpora were recorded in each case and blood samples were obtained for progesterone analysis. The concentration of plasma progesterone was about 6 ng/mL for most of gestation, including embryonic diapause, and rose to about 10 ng/mL during the final month. Progesterone declined sharply to less than 1 ng/mL at parturition. The size of the corpus luteum was constant throughout embryonic diapause, but after implantation it grew continuously until parturition. Following parturition, it regressed rapidly at first, forming a corpus albicans, and then more slowly, regression being arrested during the period of foetal growth of the following reproductive cycle. Most corpora albicantia had disappeared 1 year after their formation. Corpora albicantia may be useful indicators of reproductive history in grey seals, providing that allowance is made for the reproductive condition of females at the time of sampling and for several other possible errors which could arise. Retrospective calculation of reproductive statistics by more than 1 year using corpora albicantia is not valid for grey seals.


1976 ◽  
Vol 56 (1) ◽  
pp. 37-42 ◽  
Author(s):  
R. RAJAMAHENDRAN ◽  
P. C. LAGUË ◽  
R. D. BAKER

Progesterone levels were estimated by radioimmunoassay in blood samples obtained by venipuncture on the day of estrus and every alternate day until the onset of the next estrus in eight cycling dairy heifers. The mean level of progesterone was < 1 ng/ml during the first 2 days of the cycle, increased rapidly over the 4th–12th day period and reached a peak level value of 5.2 ± 1.1 ng/ml on day 14. Thereafter, the level declined rapidly to 2.6 ± 0.6 ng/ml on day 16 and then more gradually to 0.4 ± 0.1 ng/ml on day 21. In the second experiment, eight cycling heifers at diestrus were treated with gonadotrophin (2,000 IU PMSG or 1,000 IU PMSG + 1,000 IU HCG) followed 48 h later by 15 mg prostaglandin (PGF2α). Mid-ventral laparotomies were performed 4 days after the onset of estrus to observe ovarian activity. Progesterone levels were considerably higher in some animals and were slightly higher on the average after gonadotrophin treatments. The number of corpora lutea (CL) in these heifers ranged from 1 to 17. Progesterone levels of three heifers with 4–9 CL did not differ (P > 0.05) from those of three heifers with single CL. Two heifers each with 17 CL had peak progesterone levels of 38.4 and 27.8 ng/ml which were still high (9.6 and 26.5 ng/ml) by day 21. The remaining six heifers had low progesterone levels (< 1 ng/ml) by days 8–14, indicating premature regression of the CL. Thus, progesterone levels were not correlated with the number of CL.


2009 ◽  
Vol 21 (1) ◽  
pp. 101 ◽  
Author(s):  
O. A. Bogle ◽  
D. Ambati ◽  
R. P. Davis ◽  
G. P. Adams

The presence of an ovulation-inducing factor (OIF) in the seminal plasma of llamas and alpacas (reflex ovulators) and cattle (spontaneous ovulators) has been reported previously (Ratto MH et al. 2006 Theriogenology 66, 1102–1106). The presence of this protein in unrelated species supports the hypothesis that OIF is a conserved factor among species. The objectives of this study were to determine if OIF was present in equine and porcine seminal plasma, and whether the proportion of test animals (llamas) that ovulated in response to treatment with seminal plasma was related to dose. In Experiment 1, female llamas were assigned randomly to four groups (n = 8 or 9 per group) and treated intramuscularly with 1 mL llama seminal plasma (positive control), 3 mL equine seminal plasma, 3 mL porcine seminal plasma, or 2 mL saline (negative control). Ovulation and maximum corpus luteum diameter were compared using ultrasonography and confirmed with blood samples taken on Day 7 (Day 0 = day of treatment) to determine plasma progesterone concentration. The diameter of the preovulatory follicle at the time of treatment did not differ among groups. Equine seminal plasma induced ovulations in 3/8 (38%) llamas compared to 0/8 (0%) llamas treated with saline or porcine seminal plasma (P = 0.1). The proportion of females that ovulated was lower in the equine group (P < 0.01) compared with those animals treated with llama seminal plasma (9/9; 100%). Of the animals that ovulated, maximum CL diameter did not differ between llama and equine seminal plasma-treated groups (mean ± SEM; 11.1 ± 1.1, 11.5 ± 1.5, respectively). Similarly, progesterone concentrations were not different among llamas treated with llama seminal plasma or equine seminal plasma (mean ± SEM; 3.1 ± 0.4, 3.7 ± 1.2, respectively). The design of Experiment 2 was the same, but the dose of equine and porcine seminal plasma was increased to 8 mL and 10 mL, respectively. The proportion of females that ovulated was less (P < 0.05) in equine (2/9) and porcine (3/9) seminal plasma groups compared with the group treated with llama seminal plasma (9/9). There were no ovulations detected in llamas treated with saline (0/8). Although differences between equine, porcine, and negative control groups did not reach significance, results provide some evidence for the presence of OIF in equine and porcine seminal plasma. The effect of dose of equine and porcine seminal plasma is equivocal, suggesting that the concentration of OIF in the seminal plasma of these species may be very low and the optimal dose for inducing ovulation in test animals had not been reached. Research supported by the Natural Sciences and Engineering Council of Canada.


2010 ◽  
Vol 22 (1) ◽  
pp. 379
Author(s):  
H. Kohram ◽  
G. Mohammadi ◽  
E. Dirandeh

This study was done to consider relationships of luteal phase variables (prior to AI) with follicular waves. The estrous cycles of 15 buffaloes were synchronized with 2 i.m. injections of prostaglandin F2α given 11 days apart. The buffaloes were randomly assigned to 1 of 3 treatments. Buffaloes in the control treatment received no treatment, whereas G6 buffalos received a GnRH injection between Day 5 and 7 and G16 buffalos received a GnRH injection between Day 15 and 17 of the estrous cycle (estrus = Day 0). Daily, from estrus Day 0 to the next estrus Day 23, buffaloes had their ovaries scanned by ultrasound. Blood samples were collected by tail following each ultrasound examination from estrus until next estrus (estrus = 0). Concentrations of plasma progesterone were determined by radioimmunoassay kit. The limit of detection of the assay was 0.1 45 ng mL-1 and the intra- and interassay coeffients of variation were 7.4% and 9.2%, respectively. Data were analyzed by using PROC GLM of SAS (SAS Institute, Cary, NC, USA). For comparisons between groups, the 2-sample t-test was used for continuous traits, such as size of CL or hormone concentrations. Prospective comparisons of indices of progesterone indicated that the length of luteal lifespan was longer in 3-wave than in 2-wave buffaloes (P < 0.01). Plasma progesterone concentrations were similar at peak and measured as area under the curve on Day 5 through 17 preceding insemination in 2-wave (5.30 ± 0.40 ng mL-1) and 3-wave buffaloes (5.10 ± 0.20 ng mL-1). Length of the luteal phase (defined as from the day of estrus until the last day on which plasma progesterone remained >2 ng mL-1) was <2 days shorter in 2-wave buffaloes than in 3-wave buffaloes (15.20 ± 0.40 v. 17.10 ± 0.50 d; P < 0.05). In addition, the day of peak progesterone occurred earlier in 2-wave buffaloes (13.50 ± 0.30 v. 15.30 ± 0.70 d; P < 0.05).


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