ENDOCRINE CHANGES ASSOCIATED WITH LUTEAL REGRESSION IN THE EWE; THE SECRETION OF OVARIAN OESTRADIOL, PROGESTERONE AND ANDROSTENEDIONE AND UTERINE PROSTAGLANDIN F2α THROUGHOUT THE OESTROUS CYCLE

1976 ◽  
Vol 69 (2) ◽  
pp. 275-286 ◽  
Author(s):  
D. T. BAIRD ◽  
R. B. LAND ◽  
R. J. SCARAMUZZI ◽  
A. G. WHEELER
Keyword(s):  
Luteal Phase ◽  
Venous Blood ◽  
Prostaglandin F2α ◽  
Significant Rise ◽  
Functional Regression ◽  
Luteal Regression ◽  
Progesterone Secretion ◽  
Ovulatory Follicle ◽  
Prostaglandin F ◽  
Relationship Of

SUMMARY The concentrations of oestradiol, androstenedione, progesterone and prostaglandin F2α (PGF2α) were measured in utero-ovarian venous blood collected throughout six oestrous cycles in two ewes with utero-ovarian autotransplants. The secretion of oestradiol was closely correlated with that of androstenedione (r = 0·67, P < 0·001) indicating a common origin from the Graafian follicle. The concentration of these two steroids fluctuated at random throughout the luteal phase with the maximum secretion occurring about 2 days before the onset of oestrus. Functional regression of the corpus luteum, as indicated by a fall in the secretion of progesterone, began on day 12 or day 13, i.e. about 4 days before the onset of oestrus. In five of the six cycles the first significant rise in the secretion of PGF2α occurred on days 12–14 at the time of decline of progesterone secretion, although the release of PGF2α was maximal on the day before the onset of oestrus. There was very little release of PGF2α from the uterus before day 12. The temporal relationship of these events suggests that the uterus will only release PGF2α after it has been primed for 7–10 days with progesterone. The initiation of luteal regression is independent of secretion of oestradiol by the pre-ovulatory follicle which may, however, stimulate the further release of PGF2α responsible for irreversible structural luteolysis on the day of pro-oestrus.

Luteal steroidogenesis and regression in the rat: Progesterone secretion and lipid peroxidation induced in luteal cells by human chorionic gonadotrophin, phospholipase A2 and prostaglandin F2α

1990 ◽  
Vol 125 (3) ◽  
pp. 397-402 ◽  
Author(s):  
E. A. Greenhalgh
Keyword(s):  
Lipid Peroxidation ◽  
Luteal Phase ◽  
Prostaglandin F2α ◽  
Lipid Peroxide ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Cell Suspensions ◽  
Luteal Cell ◽  
Luteal Regression ◽  
Progesterone Secretion

ABSTRACT Mid-luteal phase (control) and mid-luteal phase luteal cell suspensions from rats given prostaglandin F2α (PGF2α) to induce luteal regression and killed 24 h later (P24-regressed) were incubated at 37 °C in serum-free medium. Progesterone secretion and lipid peroxidation induced by treatment with human chorionic gonadotrophin (hCG) alone or hCG plus phospholipase A2 and PGF2α were measured. Differences were demonstrated in progesterone secretion and lipid peroxide measurements between control and P24-regressed cell suspensions. The experiments suggested that malondialdehyde formation may be a useful indicator of luteal regression and cell death. Journal of Endocrinology (1990) 125, 397–402

SIMULTANEOUS INFUSION OF PROSTAGLANDIN E2 ANTAGONIZES THE LUTEOLYTIC ACTION OF PROSTAGLANDIN F2α IN VIVO

1977 ◽  
Vol 72 (3) ◽  
pp. 379-383 ◽  
Author(s):  
K. M. HENDERSON ◽  
R. J. SCARAMUZZI ◽  
D. T. BAIRD
Keyword(s):  
Prostaglandin E2 ◽  
Venous Blood ◽  
Prostaglandin F2α ◽  
Corpora Lutea ◽  
Progesterone Secretion ◽  
Prostaglandin F ◽  
Infusion Period

SUMMARY Corpora lutea of ewes bearing ovarian autotransplants were infused for 4 h with prostaglandin F2α (PGF2α) (10 μg/h), PGF2α + PGE2 (10 μg/h of each), PGE2 (10 μg/h) or saline on day 10 of the cycle. Ovarian venous blood obtained before, during, and up to 12 h after the infusion period, was assayed for progesterone. Prostaglandin F2α produced an immediate, rapid and sustained decline in progesterone secretion, but infusion of PGE2 together with PGF2α prevented the decline until after the infusion. Progesterone secretion was unaffected by infusion of PGE2 alone. Oestrous behaviour was observed in four out of seven animals infused with PGF2α but in only one out of six infused with PGF2α + PGE2. None of the animals infused with PGE2 alone or saline only came into heat.

Inhibin secretion by the sheep ovary during the luteal and follicular phases of the oestrous cycle and following stimulation with FSH

1988 ◽  
Vol 117 (2) ◽  
pp. 283-291 ◽  
Author(s):  
C. G. Tsonis ◽  
A. S. McNeilly ◽  
D. T. Baird
Keyword(s):  
Luteal Phase ◽  
Venous Blood ◽  
Follicular Development ◽  
Follicular Phase ◽  
Pituitary Cells ◽  
Luteal Regression ◽  
Follicular Maturation ◽  
Prostaglandin F ◽  
Late Follicular Phase ◽  
Multiple Follicular Development

ABSTRACT The secretion of oestradiol and inhibin were measured during the follicular and luteal phase of the cycle by a sensitive bioassay using sheep pituitary cells in culture in four ewes in which the left ovary had been autotransplanted to the neck. On day 12 of the cycle, premature luteal regression was induced with an injection of 100 μg cloprostenol (prostaglandin F2α analogue; PG) and ovarian venous blood was collected every 4 h for 72 h. These same four ewes were infused in the ensuing cycle with NIH-oFSH-S14 at 10 μg/h for 48 h immediately after an injection of PG and sampled as above. During the luteal phase ( − 2 h before PG) both in the control and FSH-infused cycles the inhibin secretion rate (SR) was 27–45 units/min. After PG injection, the inhibin SR declined with time to reach 3·6–5 units/min at the onset of the LH surge (60 h after PG) in the control cycle. In contrast, in the following cycle infusion of FSH after PG injection caused a slight increase in the inhibin SR which then remained raised at 42–50 units/min for up to 60 h after PG. In the late follicular phase the oestradiol SR was greater in the FSH-infused than in the control cycles, indicating multiple follicular development. In the FSH-infused cycle the preovulatory surges of LH and FSH were markedly attenuated. These data demonstrate that (1) inhibin SR is high during the luteal phase suggesting that the sheep corpus luteum secretes inhibin, (2) in the control cycle inhibin SR declines during follicular maturation at a time when oestradiol SR is increasing but FSH levels are decreasing, and (3) exogenously administered FSH stimulates the secretion of inhibin from the ovary during the follicular phase. J. Endocr. (1988) 117, 283–291

PLASMA PROGESTERONE LEVELS IN GUINEA-PIGS ACTIVELY IMMUNIZED AGAINST PROSTAGLANDIN F2α, HYSTERECTOMIZED OR TREATED WITH INTRA-UTERINE INDOMETHACIN

1975 ◽  
Vol 67 (1) ◽  
pp. 81-88 ◽  
Author(s):  
N. L. POYSER ◽  
E. W. HORTON
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Guinea Pigs ◽  
Bovine Serum ◽  
Prostaglandin F2α ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Progesterone Secretion ◽  
Bovine Serum Albumin Conjugate ◽  
Prostaglandin F

SUMMARY Five guinea-pigs actively immunized against a prostaglandin F2α(PGF2α)–bovine serum albumin conjugate showed elongated oestrous cycles. During these, corpora lutea were maintained in a functional secretory state as indicated by plasma progesterone levels. The results are compatible with the view that the PGF2α antibodies neutralized the PGF2α released from the uterus and thus prevented its normal luteolytic effect. Similar patterns of progesterone secretion were observed in two hysterectomized animals and in two animals with intra-uterine implants of indomethacin.

Ovarian secretion rates and peripheral concentrations of inhibin in normal and androstenedione-immune ewes with an autotransplanted ovary

1990 ◽  
Vol 127 (2) ◽  
pp. 285-296 ◽  
Author(s):  
B. K. Campbell ◽  
D. T. Baird ◽  
A. S. McNeilly ◽  
R. J. Scaramuzzi
Keyword(s):  
Luteal Phase ◽  
Venous Blood ◽  
Plasma Concentrations ◽  
Active Immunization ◽  
Follicular Phase ◽  
Secretion Rate ◽  
Luteal Function ◽  
Prostaglandin F ◽  
Ovarian Inhibin ◽  
Secretion Rates

ABSTRACT Active immunization of sheep against androstenedione results in an increase in ovulation rate that is associated with increased plasma levels of LH and progesterone, but not FSH. Although immunized ewes have more activated follicles the secretion rate of oestradiol is not increased. An experiment was conducted to examine the effect of androstenedione immunity on the ovarian secretion and peripheral plasma concentrations of inhibin. Merino ewes in which the left ovary had been autotransplanted to a site in the neck were divided into control (n = 5) and androstenedione-immune (n = 6) groups. Ovarian and jugular venous blood was collected every 10 min at two stages of the follicular phase, 21–27 h and 38–42 h after a luteolytic dose of an analogue of prostaglandin F2α (PG), and every 15 min for 6 h on day 10 of the subsequent luteal phase. The ewes were monitored regularly for luteal function by measurement of the concentration of progesterone and preovulatory LH surges. The concentration of inhibin in jugular and ovarian venous plasma was determined by radioimmunoassay and ovarian secretion rates and peripheral concentrations are expressed as pg of 1–26 peptide fragment of the α chain. The ovarian secretion rate of inhibin tended to be greater in androstenedione-immune ewes at all stages of the oestrous cycle measured, with this difference being statistically significant (P <0·05) during the luteal phase (100±40 and 260±80 (s.e.m.) pg/min for control and immune groups respectively). The pattern of ovarian inhibin secretion exhibited pulsatile-like fluctuations which were not associated with LH pulses. Peripheral concentrations of inhibin were generally higher in immunized than in control ewes with this difference being significant (P < 0·01) from day 4 to 14 of the luteal phase (59±5 and 110±7 ng/1 for control and immune respectively). The ovarian secretion rate of immunoactive inhibin was greater (P <0·01) during the follicular phase than during the luteal phase in both groups of ewes, and peripheral concentrations of inhibin increased (P < 0·001) following injection of PG in ewes from both treatment groups. We concluded that androstenedione immunity results in an increase in ovarian inhibin secretion, an effect that can probably be attributed to the greater number of large oestrogenic follicles present in the ovaries of these ewes. Furthermore, this increase in the concentration of inhibin may override any decrease in the negative feedback effects of ovarian steroid produced by immunization and, hence, explain the paradoxical findings of normal concentrations of FSH and raised concentrations of LH in ewes which are immunized against androstenedione. Journal of Endocrinology (1990) 127, 285–296

Influence of luteinizing hormone and prostaglandin F2α on progesterone secretion in superfused bovine luteal tissue slices

1987 ◽  
Vol 116 (3) ◽  
pp. 405-412 ◽  
Author(s):  
Martina Hoedemaker ◽  
Kirsten Grunert ◽  
D. H. A. Maas ◽  
E. Grunert
Keyword(s):  
Luteinizing Hormone ◽  
Hormone Secretion ◽  
Prostaglandin F2α ◽  
Progesterone Concentration ◽  
Tissue Slices ◽  
Progesterone Secretion ◽  
Bovine Corpus Luteum ◽  
Luteal Tissue ◽  
Prostaglandin F ◽  
Higher Doses

Abstract. Tissue slices from bovine corpus luteum from Days 12 or 13 of the oestrous cycle were super-fused for 8 h, and the progesterone secretion under the influence of prostaglandin F2α (PGF2α) and/or LH was measured. PGF2α at concentrations of 0.28 to 2800 nmol/l medium did not affect the basal progesterone secretion, whereas higher doses (7000 to 28 000 nmol/l) induced a slight increase in hormone secretion. LH, 3.4 nmol/l, caused an increase in the progesterone concentration in superfusates which exceeded the control levels (P < 0.01). This luteotropic effect of LH was not influenced by simultaneous addition of 28 to 2800 nmol/l PGF2α. PGF2α, 2800 nmol/l, did not inhibit progesterone secretion, when administered together with 0.034 to 34 nmol LH/l. Pre-superfusion with 2800 nmol/l PGF2α had no effect on the LH-stimulated increase in progesterone secretion. It is concluded that in cattle, a direct cellular effect of PGF2α, antagonizing the luteotropic function of LH, may be of less importance than other possible direct and indirect PGF2α actions.

EFFECT OF INTRA-UTERINE BEADS ALONE, OR COMBINED WITH OESTROGEN TREATMENT, ON UTERO-OVARIAN VENOUS PLASMA PROSTAGLANDIN F2α AND PROGESTERONE LEVELS IN THE GUINEA-PIG

1976 ◽  
Vol 68 (3) ◽  
pp. 445-451 ◽  
Author(s):  
F. R. BLATCHLEY ◽  
B. T. DONOVAN ◽  
N. L. POYSER
Keyword(s):  
Guinea Pig ◽  
Prostaglandin F2α ◽  
Uterine Horn ◽  
Corpora Lutea ◽  
Oestrogen Treatment ◽  
Luteal Regression ◽  
Oestradiol Benzoate ◽  
Prostaglandin F ◽  
And Control ◽  
Venous Plasma

SUMMARY The presence of beads in the guinea-pig uterus caused premature regression of the corpora lutea, and a corresponding decrease in utero-ovarian venous plasma levels of progesterone, by days 9–10 of the oestrous cycle. If the beads were placed in one horn only, premature luteal regression occurred only in the adjacent ovary. Induced luteal regression was preceded by an increased release of prostaglandin F2α (PGF2α) from the uterine horns which contained the beads. Oestradiol benzoate treatment of guinea-pigs carrying beads in one uterine horn overcame the unilateral effect and resulted in premature luteal regression in both ovaries. This was also associated with the early release of PGF2α from both uterine horns, though a difference in the timing of the release was apparent between the bead-containing (experimental) and control horns.

Ovarian production of progesterone and 20α-dihydroprogesterone in vitro following prostaglandin F2α induced luteolysis in the superluteinized rat

1984 ◽  
Vol 105 (2) ◽  
pp. 258-265 ◽  
Author(s):  
P. A. Torjesen ◽  
A. Aakvaag
Keyword(s):  
Adenylyl Cyclase ◽  
Prostaglandin F2α ◽  
Mitochondrial Fraction ◽  
Supernatant Fraction ◽  
Production Rates ◽  
Cyclic Monophosphate ◽  
Progesterone Production ◽  
Progesterone Secretion ◽  
Prostaglandin F

Abstract. Superluteinized rats were injected with the prostaglandin F2α (PGF2α) analogue cloprostenol to induce luteolysis. The treatment decreased progesterone production of ovarian homogenates from 8.9 ± 0.5 to 4.0 ± 0.7 nmol/ovary/10 min (mean ± sem) within 40 min. tochondrial fractions isolated from control and cloprostenol treated animals produced 4.7 ± 0.4 and 2.8 ± 0.3 nmol progesterone/ovary/10 min, respectively. Thus, the PGF2α analogue treatment significantly reduced mitochondrial progesterone production. Addition of the 15 000 × g supernatant fraction did not influence the progesterone production rates of the mitochondrial fraction. The basal progesterone secretion from quartered ovaries decreased from 1.50 ± 0.15 to 0.38 ± 0.05 nmol/ovary during the initial 15 min of incubation following cloprostenol administration. hCG and N6,O2'-dibutyryladenosine 3':5'-cyclic monophosphate (DBC) stimulated the progesterone secretion from quartered ovaries, but the response was delayed in ovaries obtained from cloprostenol treated animals. Although the response was delayed, the progesterone secretion following cloprostenol treatment was re-activated with cAMP either directly or via hCG. The increment in progesterone secretion above unstimulated controls in response to DBC was not influenced by the cloprostenol treatment while the increment caused by hCG was decreased. Our data suggest that: 1) PGF2α deactivates mitochondrial progesterone production, 2) this deactivation may be overcome by cAMP, and 3) PGF2α decreases gonadotrophin responsive adenylyl cyclase.

CHANGES IN OVARIAN AND PITUITARY FUNCTION IN NON-PREGNANT WOMEN DURING THE INFUSION OF PROSTAGLANDIN F2α

1975 ◽  
Vol 80 (4) ◽  
pp. 676-685 ◽  
Author(s):  
J. A. Elias ◽  
J. R. Newton ◽  
W. P. Collins
Keyword(s):  
Pregnant Women ◽  
Intravenous Administration ◽  
Luteal Phase ◽  
Prostaglandin F2α ◽  
Mean Value ◽  
Prostaglandin F ◽  
The Mean ◽  
Serial Samples ◽  
Mean Concentration ◽  
Venous Plasma

ABSTRACT The concentrations of prostaglandin F2α, progesterone, oestradiol, LH and cortisol have been determined in serial samples of peripheral venous plasma, before, during and after, the intravenous administration of prostaglandin F2α (50 μg/min, for 5 h) to 8 women in the luteal phase of the ovarian cycle. The results show that the mean concentrations of prostaglandin F2α and cortisol increased during the infusion by factors of 8.8 and 2.6 respectively. The highest levels of cortisol occurred after 3 h, and were significantly different (P < 0.0005, Student's t-test) from those obtained before the infusion. There were progressive decreases in the concentrations of LH and progesterone. After 3 h the values for LH were significantly lower (P < 0.0025) than those before the administration of prostaglandin F2α, and the lowest mean value was 26 % of the control. The values for progesterone were significantly lower (P < 0.025) after 5 h, and the mean value at this time was 38 % of the control. The pattern of the mean concentration for oestradiol was similar to that for progesterone. The levels of all 5 compounds had returned to normal within 1 h after completion of the infusion. The findings are discussed.

CONCENTRATION OF PROSTAGLANDIN F2α AND STEROIDS IN THE HUMAN CORPUS LUTEUM

1977 ◽  
Vol 73 (1) ◽  
pp. 115-122 ◽  
Author(s):  
I. A. SWANSTON ◽  
K. P. McNATTY ◽  
D. T. BAIRD
Keyword(s):  
Menstrual Cycle ◽  
Corpus Luteum ◽  
Luteal Phase ◽  
Prostaglandin F2α ◽  
Corpora Lutea ◽  
Progesterone Concentration ◽  
Late Luteal Phase ◽  
Prostaglandin F ◽  
Human Corpus Luteum

SUMMARY The concentration of prostaglandin F2α (PGF2α), progesterone, pregnenolone, oestradiol-17β, oestrone, androstenedione and testosterone was measured in corpora lutea obtained from 40 women at various stages of the menstrual cycle. The concentration of PGF2α was significantly higher in corpora lutea immediately after ovulation (26·7 ± 3·9 (s.e.m.) ng/g, P < 0·005) and in corpora albicantia (16·3 ± 3·3 ng/g, P < 0·005) than at any other time during the luteal phase. There was no correlation between the concentration of PGF2α and that of any steroid. The progesterone concentration was highest in corpora lutea just after ovulation (24·9 ± 6·7 μg/g) and in early luteal groups (25·7 ± 6·8 μg/g) but declined significantly (P < 0·05) to its lowest level in corpora albicantia (1·82 ± 0·66 μg/g). The concentration of oestradiol-17β in the corpus luteum and luteal weight were significantly greater during the mid-luteal phase than at any other stage (concentration 282 ± 43 ng/g, P < 0·05; weight 1·86 ± 0·18 g, P < 0·005). The results indicate that regression of the human corpus luteum is not caused by a rise in the ovarian concentration of PGF2α in the late luteal phase of the cycle.

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