RECEPTORS FOR GONADOTROPHIN AND PROSTAGLANDIN F2α IN BOVINE CORPORA LUTEA OF EARLY, MID AND LATE LUTEAL PHASE

1979 ◽  
Vol 91 (3) ◽  
pp. 529-537 ◽  
Author(s):  
Ch. V. Rao ◽  
V. L. Estergreen ◽  
F. R. Carman ◽  
G. E. Moss
Keyword(s):  
Luteal Phase ◽  
Specific Binding ◽  
Prostaglandin F2α ◽  
Progressive Increase ◽  
Corpora Lutea ◽  
Apparent Dissociation Constant ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Late Luteal Phase ◽  
Dissociation Constant Kd

ABSTRACT A total of 15 corpora lutea representing early (day 3), mid (day 13) and late luteal phase (days 20 and 21–24) were obtained by ovariectomy on cycling cows. The luteal weights and peripheral plasma progesterone levels just prior to ovariectomy, were consistent with the above luteal phases. The specific binding of [125I]human chorionic gonadotrophin to membranes prepared from corpora lutea was significantly higher (P < 0.01) for days 13 and 20 than for days 3 and 21–24. The binding in day 21–24 corpora lutea was higher (P < 0.01) than day 3. Although there was no difference either in number or affinity (apparent dissociation constant (Kd) = 0.04 nm) of gonadotrophin receptors in days 13 and 20 corpora lutea, only in the former did the binding correlate well with plasma progesterone levels. The specific binding of [3H]prostaglandin (PG)F2α to the membranes of these same corpora lutea showed a progressive increase (P < 0.01) from day 3, reached the highest value at a time when corpora lutea were actively regressing (day 20) and then declined (P < 0.01) by day 21–24. Although a considerable number of PGF2α receptors existed at day 13, the affinity of these same receptors was 203 times lower (Kd = 3458 nm) than the affinity of receptors in day 20 corpora lutea (Kd = 17 nm). In summary, the above results show that gonadotrophin receptors correlate with luteotrophic, whereas PGF2α receptors correlate with luteolytic phases in bovine corpora lutea.

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.

EFFECTS OF OESTROGEN AND PROSTAGLANDIN F2α ON LUTEINIZING HORMONE RECEPTORS IN HUMAN CORPORA LUTEA

1981 ◽  
Vol 88 (3) ◽  
pp. 401-408 ◽  
Author(s):  
RYOSUKE NAKANO ◽  
MAREO YAMOTO ◽  
MASAFUMI IWASAKI
Keyword(s):  
Menstrual Cycle ◽  
Binding Sites ◽  
Luteal Phase ◽  
Hormone Receptors ◽  
Specific Binding ◽  
Prostaglandin F2α ◽  
Scatchard Analysis ◽  
Corpora Lutea ◽  
Luteal Tissue ◽  
Number Of Binding Sites

The binding of 125I-labelled human LH (hLH) to the 2000 g subcellular fraction of human corpora lutea of the menstrual cycle was examined. Displacement studies demonstrated that 125I-labelled hLH was specifically bound in the 2000 g fraction of human luteal tissue. Specific binding of 125I-labelled hLH was demonstrated in all the corpora lutea examined except for two aged corpora lutea at an early proliferative phase of the cycle. The number of binding sites for hLH increased between the early to mid-luteal phase and decreased towards the late luteal phase. However, the apparent dissociation constant (Kd) in each corpus luteum did not vary throughout the menstrual cycle. In addition, the effects of treatment with diethylstilboestrol diphosphate (DES) and prostaglandin F2α (PGF2α) on the binding of 125I-labelled hLH to the 2000 g fraction of luteal tissue were investigated and the changes in hLH receptors were estimated by Scatchard analysis. The number of binding sites were 1·59 × 10−14 mol/mg protein in control tissue, 0·86 × 10 −14 mol/mg protein in DES-treated luteal tissue and 2·95 × 10−14 mol/mg protein in PGF2α-treated luteal tissue. Thus, the binding sites for hLH decreased as a result of treatment with DES and increased by treatment with PGF2α. In contrast, the apparent Kd in each luteal tissue revealed almost the same value (4·24 × 10−10 to 6·07 × 10−10 mol/l) after treatment with DES or PGF2α. The results of the present study suggest that oestrogen and prostaglandin might have an important role in modulating hLH receptor in human corpora lutea.

Receptors for lactogenic hormones in the porcine corpus luteum: properties and luteal phase concentrations

1987 ◽  
Vol 113 (3) ◽  
pp. 355-364 ◽  
Author(s):  
T. A. Bramley ◽  
G. S. Menzies
Keyword(s):  
Metal Ions ◽  
Luteal Phase ◽  
Specific Binding ◽  
Divalent Metal ◽  
Corpora Lutea ◽  
Divalent Metal Ions ◽  
Binding Reaction ◽  
Late Luteal Phase ◽  
Lactogenic Hormones ◽  
Ovine Prolactin

ABSTRACT Homogenates of pig corpora lutea contained specific, high-affinity receptors for ovine prolactin (oPRL) and human GH (hGH). Specific hormone binding was enhanced by divalent metal ions, but only when included in the binding reaction. Divalent metal ions did not act by increasing the recovery of bound hormone by low-speed centrifugation, but appeared to promote the formation of a more stable hormone– receptor complex. Both oPRL and hGH tracers were bound in similar amounts and with similar affinities by pig luteal homogenates and the concentrations of either unlabelled hormone required to displace specific binding of either tracer by 50% were identical. In contrast, 125I-labelled oGH failed to bind to pig luteal homogenates and oGH competed poorly for hGH or oPRL binding. Only hormones with prolactin-like activity competed for 125I-labelled oPRL binding. Specific prolactin binding was low in recently ovulated and early luteal phase corpora lutea, increased significantly in the mid-luteal phase and declined once more in the late luteal phase. Receptor concentrations increased with increasing gestational age. J. Endocr. (1987) 113, 355–364

PROGESTERONE CONCENTRATION IN THE PERIPHERAL PLASMA OF SHEEP DURING THE OESTROUS CYCLE

1969 ◽  
Vol 45 (3) ◽  
pp. 459-469 ◽  
Author(s):  
G. D. THORBURN ◽  
J. M. BASSETT ◽  
I. D. SMITH
Keyword(s):  
Thin Layer ◽  
Luteal Phase ◽  
Jugular Vein ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Layer Chromatography ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY Using a protein-binding technique, progesterone concentrations in peripheral plasma (jugular vein) were measured throughout the oestrous cycle of 24 ewes. Examination of the specificity of the method by thin-layer chromatography indicated that interference from other steroids was not significant in sheep plasma. During the first 4 days of the cycle (days 0–3), plasma progesterone concentrations were below 0·4 ng./ml., increasing to a mean level of 1·5–2·5 ng./ml. between days 4 and 9, and remaining at this level for approximately 5 days, before declining rapidly on days 14 and 15 to reach a low level on the day before oestrus. The progesterone concentration on the day of oestrus was extremely low (0·1 ng./ml.), and was of the same order as that found in the plasma of wethers and anoestrous or ovariectomized ewes. Three ewes, superovulated with pregnant mare serum gonadotrophin, showed marked elevation of peripheral progesterone concentration during the luteal phase of the cycle, the concentration being proportional to the number of corpora lutea formed.

Luteolytic effect of prostaglandin F2α in Boran and Boran × Friesian cross-bred heifers

1993 ◽  
Vol 120 (1) ◽  
pp. 103-106 ◽  
Author(s):  
E. R. Mutiga ◽  
E. Mukasa-Mugerwa ◽  
T. Azage
Keyword(s):  
Luteal Phase ◽  
Prostaglandin F2α ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Significant Difference ◽  
Prostaglandin F ◽  
Elisa Technique ◽  
The Cross

SUMMARYThe luteolytic effect of prostaglandin F2α (PGF2α) during the confirmed luteal phase of the oestrous cycle was evaluated in ten Boran and ten Boran × Friesian cross-bred heifers. Following injection with 25 mg Lutalyse, animals were bled every 6 h for 96 h and plasma progesterone (P4) determined by the ELISA technique. Borans had significantly (P < 0·05) smaller corpora lutea (12·01±0·72 ν. 17·03±2·10 mm) and responded faster to PGF2α injection (65·57±1·40 ν. 78·27±2·18 h) than the cross-bred heifers. However, there was no significant difference in either the initial P4 values (6.24±0·98 ν. 8·00±1·71 ng/ml) or the rate of its decline following PGF2α injection between the two breeds. Values declined sharply to basal levels (11% of the initial pretreatment values) within 48 h in both breeds. All ten cross-breds and eight Borans showed standing oestrus within a week of treatment. However, oestrus was better synchronized (P < 0·05) in Borans than cross-breds. It was concluded that PGF2α is effective for oestrus synchronization in both breeds, but oestrus occurred earlier and was more precise in Borans than in cross-breds.

PROGESTERONE PRODUCTION BY DISPERSED CELLS FROM HUMAN CORPUS LUTEUM: STIMULATION BY GONADOTROPHINS AND PROSTAGLANDIN F2α; LACK OF RESPONSE TO ADRENALINE AND ISOPRENALINE

1980 ◽  
Vol 87 (2) ◽  
pp. 247-254 ◽  
Author(s):  
M. C. RICHARDSON ◽  
G. M. MASSON
Keyword(s):  
Luteal Phase ◽  
Prostaglandin F2α ◽  
Maximum Level ◽  
Luteal Cell ◽  
Corpora Lutea ◽  
Tissue Samples ◽  
Progesterone Production ◽  
Late Luteal Phase ◽  
Prostaglandin F ◽  
Human Corpus Luteum

Progesterone production was assessed following short-term incubations of luteal cell suspensions prepared from tissue samples of human corpora lutea obtained at specific times throughout the luteal phase of the menstrual cycle. Luteal cells responded rapidly and sensitively to human chorionic gonadotrophin (HCG; concentration required for 50% maximum response, 0·1–1·0 i.u./ml) with a maximum level of response (five- to tenfold higher than basal production) similar to that elicited by human LH or N6,02-dibutyryl cyclic AMP. In the absence of gonadotrophin or in the presence of sub-maximal (but not maximal) concentrations of HCG, progesterone production by mid-luteal phase cells was stimulated by prostaglandin F2α (1 μmol/l), an effect not observed during the late-luteal phase. l-Adrenaline and l-isoprenaline failed to elicit significant increases in the level of progesterone production.

STIMULATION BY HUMAN CHORIONIC GONADOTROPHIN OF OESTRADIOL PRODUCTION BY DISPERSED CELLS FROM HUMAN CORPUS LUTEUM: COMPARISON WITH PROGESTERONE PRODUCTION; UTILIZATION OF EXOGENOUS TESTOSTERONE

1981 ◽  
Vol 91 (2) ◽  
pp. 197-203 ◽  
Author(s):  
M. C. RICHARDSON ◽  
G. M. MASSON
Keyword(s):  
Luteal Phase ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Cell Suspensions ◽  
Corpora Lutea ◽  
Progesterone Production ◽  
Late Luteal Phase ◽  
Oestradiol Production ◽  
Dispersed Cells

Cell suspensions were prepared from tissue samples of human corpora lutea obtained during the mid- and late-luteal phase of the menstrual cycle. Both oestradiol and progesterone production by dispersed cells were stimulated by similar concentrations of human chorionic gonadotrophin (hCG). As the degree of stimulation of production by hCG was greater for progesterone than for oestradiol (five- to tenfold compared with two- to threefold higher than basal production), the ratio of progesterone to oestradiol produced varied according to the level of trophic stimulation. A comparison of cell suspensions prepared from mid- and late-luteal phase corpora lutea, exposed to the same concentration of hCG (10 i.u./ml) in vitro, did not reveal a shift to oestradiol production in the late-luteal phase. Provision of additional testosterone during incubation raised the level of oestradiol production by dispersed luteal cells. At an optimum concentration of testosterone (1 μmol/l), oestradiol synthesis was not raised further in the presence of hCG or N6, O2-dibutyryl cyclic AMP, suggesting a lack of induction or activation of the aromatase system by gonadotrophin in short-term cultures. Basal and stimulated levels of progesterone production were not significantly impaired in the presence of testosterone.

scholarly journals Delayed effect of low progesterone concentrations on bovine uterine PGF(2alpha) secretion in the subsequent oestrous cycle

Reproduction ◽  
2001 ◽  
pp. 643-648 ◽  
Author(s):  
A Shaham-Albalancy ◽  
Y Folman ◽  
M Kaim ◽  
M Rosenberg ◽  
D Wolfenson
Keyword(s):  
Corpus Luteum ◽  
Luteal Phase ◽  
Oestrous Cycle ◽  
Delayed Effect ◽  
Plasma Progesterone ◽  
Progesterone Secretion ◽  
Progesterone Treatment ◽  
Late Luteal Phase ◽  
Subsequent Cycle ◽  
Concentration Curves

Low progesterone concentrations during the bovine oestrous cycle induce enhanced responsiveness to oxytocin challenge late in the luteal phase of the same cycle. The delayed effect of low progesterone concentrations during one oestrous cycle on uterine PGF(2alpha) secretion after oxytocin challenge on day 15 or 16 of the subsequent cycle was studied by measuring the concentrations of the major PGF(2alpha) metabolite (13,14-dihydro-15-keto PGF(2alpha); PGFM) in plasma. Two experiments were conducted, differing in the type of progesterone treatment and in the shape of the low progesterone concentration curves. In Expt 1, progesterone supplementation with intravaginal progesterone inserts, with or without an active corpus luteum, was used to obtain high, or low and constant plasma progesterone concentrations, respectively. In Expt 2, untreated cows, representing high progesterone treatment, were compared with cows that had low but increasing plasma progesterone concentrations that were achieved by manipulating endogenous progesterone secretion of the corpus luteum. Neither experiment revealed any differences in plasma progesterone concentrations between the high and low progesterone groups in the subsequent oestrous cycle. In both experiments, both groups had similar basal concentrations of PGFM on day 15 (Expt 1) or 16 (Expt 2) of the subsequent oestrous cycle, 18 days after progesterone treatments had ended. In both experiments, the increases in PGFM concentrations in the low progesterone groups after an oxytocin challenge were markedly higher than in the high progesterone groups. These results indicate that low progesterone concentrations during an oestrous cycle have a delayed stimulatory effect on uterine responsiveness to oxytocin during the late luteal phase of the subsequent cycle. This resulting increase in PGF(2alpha) secretion may interfere with luteal maintenance during the early stages of pregnancy.

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.

Synchronization of oestrus and subsequent fertility in cattle, using the prostaglandin F2α analogue, ICI 80996 (cloprostenol)

1976 ◽  
Vol 16 (81) ◽  
pp. 437 ◽  
Author(s):  
H Hearnshaw
Keyword(s):  
Artificial Insemination ◽  
Luteal Phase ◽  
Prostaglandin F2α ◽  
Optimum Time ◽  
Subcutaneous Injections ◽  
Late Luteal Phase ◽  
Initial Injection ◽  
Subsequent Fertility ◽  
Subsequent Cycle ◽  
Cycle Lengths

The prostaglandin analogue, ICI 80996 (cloprostenol), was administered subcutaneously to synchronize oestrus in cattle. One injection, or two injections 12 days apart, of 400 pg gave optimal results (78 and 72 per cent synchronized respectively) for the Hereford cross heifers used. Heifers treated with cloprostenol from days one to five of the cycle, did not respond to the first injection, but did so to a second injection given 12 days later. A greater percentage of heifers, treated in the mid or late luteal phase of the cycle, exhibited oestrus after the first injection of cloprostenol than after the second injection. The percentage of these heifers showing induced oestrus varied from 44 to 100 per cent. There was a peak in the incidence of oestrus between 49 and 72 hours after injection but the distribution ranged from 24 to 120 hours. Peripheral blood progesterone concentrations, palpation of the ovaries and subsequent cycle lengths, indicated that the cloprostenol had no adverse effects in the majority of heifers. However, about 30 per cent of the heifers that responded to an initial injection of cloprostenol given in the mid luteal phase of the cycle failed to respond to a second injection. Some of these heifers had abnormal progesterone profiles and subsequent reproductive patterns. Fertility, following one or two subcutaneous injections of cloprostenol and artificial insemination at the set times of 72 and 96 hours, was 30 and 46 per cent respectively. However, if only heifers inseminated at the optimum time were considered, fertility at pregnancy diagnosis (73 and 65 per cent) and calving (53 and 57 per cent) was acceptable.

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