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.

THE EFFECT OF PROSTAGLANDIN F2α ON PROGESTERONE, OESTRADIOL AND LUTEINIZING HORMONE SECRETION IN SHEEP WITH OVARIAN TRANSPLANTS

1972 ◽  
Vol 55 (2) ◽  
pp. 253-263 ◽  
Author(s):  
W. A. CHAMLEY ◽  
JOAN M. BUCKMASTER ◽  
M. D. CAIN ◽  
J. CERINI ◽  
MILDRED E. CERINI ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Hormone Secretion ◽  
Prostaglandin F2α ◽  
Luteinizing Hormone Secretion ◽  
Ovarian Steroidogenesis ◽  
Progesterone Secretion ◽  
Prostaglandin F ◽  
Low Levels

SUMMARY The luteolytic properties of prostaglandin F2α (PGF2α) were studied in experiments on sheep with ovarian autotransplants. PGF2α was infused at the rate of 40, 10 and 2 μg/h for 4·0, 7·0 and 9·5–18·0 h respectively. At rates of 40 and 10 μg/h, progesterone secretion decreased to 50% of the control levels in 2·6 ± 1·4 h and fell to 8–30 μg/h within 36–52 h from the start of infusion. The onset of oestrus occurred 42–66 h after the infusions had started and a typical pre-ovulatory surge of luteinizing hormone (LH) was observed 52–66 h after infusing PGF2α. On occasions, this surge was accompanied by a brief peak of oestradiol-17β secretion and shortly thereafter ovarian steroidogenesis decreased to very low levels. In four sheep infused at a rate of 2 μg/h, peripheral progesterone values decreased gradually and only one animal returned to oestrus. It would seem that 2 μg/h is close to the minimum intra-arterial dose to cause luteolysis in the sheep.

scholarly journals Mechanism of action of noradrenaline on secretion of progesterone and oxytocin by the bovine corpus luteum in vitro

2001 ◽  
Vol 49 (1) ◽  
pp. 39-51 ◽  
Author(s):  
Grażyna Miszkiel ◽  
J. Kotwica
Keyword(s):  
Corpus Luteum ◽  
Mechanism Of Action ◽  
Hydroxysteroid Dehydrogenase ◽  
Luteal Cells ◽  
Progesterone Secretion ◽  
Bovine Corpus Luteum ◽  
Progesterone Synthesis ◽  
Luteal Tissue ◽  
Prostaglandin F

The present studies were conducted: (1) to determine which β-adrenoceptor subtypes are involved in progesterone and oxytocin (OT) secretion, (2) to examine whether noradrenaline (NA) acts directly on the cytochrome P-450scc and 3β-hydroxysteroid dehydrogenase (3β-HSD), and (3) to study the effect of prostaglandin F2α, (PGF2α) on NA-stimulated steroidogenesis in luteal cells. The effect of NA on progesterone secretion from luteal slices of heifers on days 8–12 of the oestrous cycle was blocked by both atenolol (β1-antagonist) and ICI 118.551 hydrochloride (β2-antagonist). OT secretion was blocked only after treatment with ICI 118.551 hydrochloride (P < 0.05). Dobutamine (10−4−10−6), a selective β1 agonist and salbutamol (10−4−10−6), a selective β2 agonist, both increased progesterone production (P < 0.01) with an efficiency comparable to that produced by NA (P < 0.01). The increase of OT content in luteal slices was observed only after treatment with salbutamol at the dose of 10−5M (P < 0.01). Dobutamine had no effect on OT production at any dose. A stimulatory effect of NA on cytochrome P-450scc activity (P < 0.05) was demonstrated using 25-hydroxycholesterol as substrate. 3β-HSD activity also increased following NA (P < 0.01) or pregnenolone (P < 0.05) and in tissue treated with pregnenolone together with NA (P < 0.01). PGF decreased progesterone synthesis (P < 0.05) and 3β-HSD activity (P < 0.01) in tissue treated with NA. We conclude that NA stimulates progesterone secretion by luteal β1- and β2-adrenoceptors, while OT secretion is probably mediated only via the β2-receptor. NA also increases cytochrome P-450scc and 3β-HSD activity. PGF inhibits the luteotropic effect of NA on the luteal tissue.

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 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.

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.

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.

PROGESTERONE, PROSTAGLANDIN F2α, AND OESTRADIOL IN THE UTERO-OVARIAN VENOUS PLASMA OF NON-PREGNANT AND EARLY, UNILATERALLY PREGNANT GUINEA-PIGS

1975 ◽  
Vol 67 (2) ◽  
pp. 225-229 ◽  
Author(s):  
F. R. BLATCHLEY ◽  
F. M. MAULE WALKER ◽  
N. L. POYSER
Keyword(s):  
Guinea Pig ◽  
Early Pregnancy ◽  
Guinea Pigs ◽  
Prostaglandin F2α ◽  
Progesterone Secretion ◽  
Prostaglandin F ◽  
Venous Plasma

SUMMARY Levels of progesterone, prostaglandin F2α (PGF2α) and oestradiol in the utero-ovarian venous plasma of non-pregnant and early, unilaterally pregnant guinea-pigs were compared. Progesterone levels fell from day 12 to day 15 in the non-pregnant animals, while levels of PGF2α and oestradiol increased during this period. In contrast, in the pregnant guinea-pigs, progesterone levels remained high up to day 15 and PGF2α and oestradiol levels remained low in plasma from both the pregnant and non-pregnant sides. These findings support the hypothesis that the guinea-pig conceptus secretes an anti-luteolytic factor in early pregnancy, which reduces the amount of PGF2α produced by the uterus and released into the uterine veins and thereby allows luteal maintenance and continued progesterone secretion. Oestradiol, in the presence of progesterone, is regarded as the physiological stimulus for normal uterine PGF2α synthesis and release. Consequently, the inhibition of ovarian oestradiol secretion seen in early pregnancy is probably at least part of the mechanism by which the anti-luteolytic factor produced by the conceptus reduces PGF2α synthesis by and release from the uterus.

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