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.

THE RELATIONSHIP BETWEEN THE UTERUS AND OVARIES DURING EARLY PREGNANCY IN THE GUINEA-PIG

1972 ◽  
Vol 53 (2) ◽  
pp. 295-301 ◽  
Author(s):  
F. R. BLATCHLEY ◽  
B. T. DONOVAN
Keyword(s):  
Guinea Pig ◽  
Early Pregnancy ◽  
Guinea Pigs ◽  
Uterine Horn ◽  
Vaginal Smear ◽  
Corpora Lutea ◽  
Luteal Regression ◽  
Experimental Animals ◽  
Decidual Reaction ◽  
The Relationship

SUMMARY In mated guinea-pigs one uterine horn was rendered sterile by ligation of the oviduct 2 or 3 days after finding spermatozoa in the vaginal smear. Two glass beads were inserted into the sterile horn on each of days 3–12 and on day 14 in experimental animals but not in controls. At autopsy on day 20 large corpora lutea were present in both ovaries of the control animals. The presence of beads that had been introduced on days 3 and 4 and on days 10–14 resulted in marked regression of the corpora lutea in the adjacent ovary, in the absence of a decidual reaction in the uterus, while luteal enlargement typical of pregnancy occurred in the contralateral ovary. Beads inserted on days 5–8 caused decidualization in the sterile horn but did not induce premature luteal regression in the ipsilateral ovary.

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.

THE EFFECT OF PROSTAGLANDIN F2α AND PROSTAGLANDIN E2 UPON LUTEAL FUNCTION AND OVULATION IN THE GUINEA-PIG

1972 ◽  
Vol 53 (3) ◽  
pp. 493-501 ◽  
Author(s):  
F. R. BLATCHLEY ◽  
B. T. DONOVAN
Keyword(s):  
Guinea Pigs ◽  
Day Treatment ◽  
Prostaglandin F2α ◽  
Prostaglandin E ◽  
Corpora Lutea ◽  
Histamine Dihydrochloride ◽  
Luteal Regression ◽  
Luteal Function ◽  
Prostaglandin F ◽  
Effect Of Treatment

SUMMARY The effect of treatment with prostaglandin F2α (PGF2α on luteal function was examined in hysterectomized guinea-pigs. Regression of corpora lutea was found to occur when 0·25 mg (or more) was injected daily for 3 days and ovulation usually ensued within 5 days after treatment. The administration of 1 mg PGF2α daily for 7 days caused marked luteolysis but ovulation did not occur. Ovulation was blocked in three of four intact female guinea-pigs given 1 mg PGF2α/day for 7 days from day 15, but took place normally in five females injected with 0·25 mg/day. Treatment of hysterectomized guinea-pigs with 0·62 mg adrenaline hydrochloride/day, 1·97 mg atropine sulphate/day or 0·52 mg histamine dihydrochloride/day did not cause luteal regression, while the injection of 0·25 mg or 1 mg prostaglandin E2 daily for 3 days was likewise ineffective.

OESTROGEN AND PROGESTERONE AND THE FUNCTION OF THE CORPORA LUTEA IN THE GUINEA-PIG

1970 ◽  
Vol 47 (2) ◽  
pp. 225-230 ◽  
Author(s):  
K. P. BLAND ◽  
B. T. DONOVAN
Keyword(s):  
Guinea Pig ◽  
Guinea Pigs ◽  
Single Injection ◽  
Glass Beads ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Luteal Regression ◽  
Oestradiol Benzoate

SUMMARY Regression of the corpora lutea in the guinea-pig could be accelerated by treatment with 10 μg. oestradiol benzoate daily over days 3–11 of the oestrous cycle. A single injection of 10 μg. oestradiol benzoate on day 3 was also effective. The luteolytic effect of oestrogen was abolished by hysterectomy, indicating that the uterus is involved in the mediation of the response. Progesterone (5 mg. daily over days 3–11) enhanced the luteal regression brought about by the presence of two glass beads in one horn of the uterus, but did not affect luteal size in otherwise intact females. Treatment of guinea-pigs with 5 mg. progesterone daily over days 2–5 or 4–7 failed to alter the length of the oestrous cycle.

GONADAL HORMONES AND THE CONTROL OF OVULATION IN THE GUINEA-PIG

1972 ◽  
Vol 55 (3) ◽  
pp. 599-607 ◽  
Author(s):  
B. T. DONOVAN ◽  
A. N. LOCKHART
Keyword(s):  
Guinea Pig ◽  
Corpus Luteum ◽  
Acute Treatment ◽  
Gonadal Hormones ◽  
Time Of Day ◽  
Gonadal Steroids ◽  
Corpora Lutea ◽  
Plasma Progesterone ◽  
Gonadotrophin Secretion ◽  
Oestradiol Benzoate

SUMMARY The release of ovulating hormone after acute treatment with gonadal steroids, or corpus luteum removal on different days of the oestrous cycle, was studied in the guinea-pig. Injection of 25, 50 or 100 μg oestradiol or 2·5 mg progesterone on day 13 of the cycle had no effect upon gonadotrophin secretion as judged by follicular histology, but markedly altered the sizes of the corpora lutea of the previous ovulation. Treatment with oestradiol on day 14 did not elicit gonadotrophin secretion. However, administration of the same hormones to animals given 10 μg oestradiol benzoate 24 h earlier caused ovulation or follicular luteinization. Progesterone (2·5 mg) appeared least effective in stimulating gonadotrophin release; 25 μg oestradiol were more effective when given at 12.00 h than at 24.00 h but treatment with both hormones caused ovulation when given at either time of day. Luteal volumes were not affected. Removal of corpora lutea during the second half of the cycle advanced the time of expected ovulation to day 15 or earlier when the procedure was carried out on days 8 or 9, but not on days 10–13. It is concluded that 4–5 days must elapse between the fall in plasma progesterone level associated with corpus luteum regression and the release of ovulating hormone.

EFFECTS OF PROSTAGLANDIN F2α ON SOME REPRODUCTIVE PROCESSES OF HAMSTERS AND RATS

1972 ◽  
Vol 53 (2) ◽  
pp. 201-213 ◽  
Author(s):  
A. P. LABHSETWAR
Keyword(s):  
Prostaglandin F2α ◽  
Concomitant Administration ◽  
Corpora Lutea ◽  
Fallopian Tubes ◽  
Racemic Form ◽  
Endocrine Profile ◽  
Prostaglandin F ◽  
Blue Reaction ◽  
Egg Transport ◽  
Reproductive Processes

SUMMARY In an attempt to characterize the endocrine profile of prostaglandin F2α (PGF2α) in relation to the female reproductive system, the compound (racemic form) was administered to hamsters and rats in various reproductive states. The prostaglandin terminated pregnancy when given once a day either subcutaneously (50 μg/hamster) or orally (1·5–2 mg/hamster) from Days 4 to 6 of pregnancy inclusive, or as a single subcutaneous injection (50 μg/animal) on Day 4. In the rat, higher (500 μg/injection) and more frequent (twice daily) s.c. injections were required to get even foetal resorption. Concomitant administration of progesterone (4 mg/animal) in either species protected pregnancy. Prostaglandin F2α terminated pregnancy without interfering with the Pontamine blue reaction, suggesting that its antifertility effects were not mediated by inhibition of implantation. In both hamsters and rats the prostaglandin markedly reduced the size of deciduomata which could be restored to normal by administration of progesterone. Prostaglandin F2α delayed passage of zygotes through the Fallopian tubes in a proportion of rats but failed to accelerate egg transport in rats and hamsters. Furthermore, it caused a marked histological degeneration of the corpora lutea and induced formation of a fresh set of corpora lutea in pseudopregnant, pregnant and pseudopregnant—hysterectomized hamsters. These deleterious effects of prostaglandin were accompanied, in hamsters, by the appearance of freshly ovulated tubal ova. Most of the endocrine effects of PGF2α observed in this study can be accounted for by its luteolytic property.

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.

THE CONCENTRATION OF PROSTAGLANDIN F2α IN MATERNAL PLASMA, FOETAL PLASMA AND AMNIOTIC FLUID DURING PREGNANCY IN WOMEN

1975 ◽  
Vol 79 (3) ◽  
pp. 589-597 ◽  
Author(s):  
D. A. Johnson ◽  
P. A. Manning ◽  
J. F. Hennam ◽  
J. R. Newton ◽  
W. P. Collins
Keyword(s):  
Amniotic Fluid ◽  
Prostaglandin F2α ◽  
Late Pregnancy ◽  
Maternal Plasma ◽  
Uterine Contractions ◽  
Prostaglandin F ◽  
Serial Samples ◽  
Considerable Individual Variation ◽  
Venous Plasma

ABSTRACT The concentration of prostaglandin F2α has been determined in serial samples of peripheral venous plasma from women at defined times during labour, and studied in detail throughout two consecutive uterine contractions. In addition, the same compound has been measured in single samples of uterine venous plasma, cord venous plasma, and amniotic fluid in groups of patients during early and late pregnancy, labour and at delivery of the baby. The results from the analysis of peripheral venous plasma show that there is considerable individual variation in the concentration of prostaglandin F2α during labour (mean ± sd, 33.1 ± 11.6 pg/ml). However, it is not possible to establish a definite correlation with either the latent or accelerated phases or with the time of delivery. Furthermore, there is no apparent temporal relationship between the concentrations in peripheral venous plasma and the contractile state of the uterus as assessed by external tocography. In early pregnancy (16th to 20th week) the concentration of prostaglandin F2α (pg/ml, mean ± sd) in peripheral venous plasma is 26.3 ± 4.3 and in amniotic fluid 32.7 ± 26.5. At the 36th week to the start of labour the corresponding values are 27.1 ± 8.1 and 110.0 ± 73.8. At the same time the levels in cord plasma and uterine venous plasma are 100.4 ± 74.9 and 87.9 ± 55.0 respectively. During labour there is a significant increase (P < 0.005, Student's t-test) in the concentration in amniotic fluid (335.1 ± 171.0). The results are discussed in relation to the possible role of prostaglandin F2α in the process of parturition.

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.

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.

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