PROSTAGLANDIN E, THROMBOXANE B2 AND 6-OXO-PROSTAGLANDIN F1α IN AMNIOTIC FLUID AND MATERNAL PLASMA OF RHESUS MONKEYS (MACACA MULATTA) DURING THE LATTER THIRD OF GESTATION

1979 ◽  
Vol 81 (3) ◽  
pp. 345-349 ◽  
Author(s):  
J. S. ROBINSON ◽  
R. NATALE ◽  
L. CLOVER ◽  
M. D. MITCHELL
Keyword(s):  
Rhesus Monkey ◽  
Amniotic Fluid ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Maternal Plasma ◽  
Thromboxane B2 ◽  
Prostaglandin E ◽  
Peripheral Plasma ◽  
Prostaglandin F ◽  
Serial Samples

The concentrations of prostaglandin E (PGE), thromboxane B2 (TXB2) and 6-oxo-prostaglandin F1α (6-oxo-PGF1α) were measured by radioimmunoassay in serial samples of amniotic fluid and maternal peripheral plasma in the latter third of pregnancy in rhesus monkeys (Macaca mulatta). The samples were collected under ketamine-induced anaesthesia. The concentration of PGE was undetectable in amniotic fluid until a few days before delivery when a large increase was observed in three of the five animals. There were small increases of TXB2 and 6-oxo-PGF1α in amniotic fluid before delivery. In maternal plasma the concentrations of PGE, TXB2 and 6-oxo-PGF1α were generally higher and more variable than in amniotic fluid and did not increase with advancing gestation. It is suggested that increased production of primary prostaglandins occurs before, and is involved in, the onset of parturition in the rhesus monkey.

INFLUENCE OF OOPHORECTOMY, LUTEECTOMY, FOETAL DEATH AND DEXAMETHASONE ON THE PERIPHERAL PLASMA LEVELS OF OESTROGENS AND PROGESTERONE IN THE PREGNANT MACACA MULATTA

1974 ◽  
Vol 75 (3) ◽  
pp. 601-616 ◽  
Author(s):  
W. T. K. Bosu ◽  
E. D. B. Johansson ◽  
C. Gemzell
Keyword(s):  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Plasma Levels ◽  
Rhesus Monkeys ◽  
Deleterious Effect ◽  
Maternal Plasma ◽  
Relative Influence ◽  
Foetal Death ◽  
Bilateral Oophorectomy ◽  
Peripheral Plasma

ABSTRACT The influence of bilateral oophorectomy, luteectomy, dexamethasone injections and foetal death on the peripheral plasma levels of oestrogens1) and progesterone was studied in pregnant rhesus monkeys. After bilateral oophorectomy and luteectomy, pregnancy proceeded normally and the plasma levels of oestrogens and progesterone attained levels similar to those in intact monkeys, but the progesterone levels after parturition were comparatively lower. Dexamethasone injections into pregnant monkeys had no deleterious effect on the outcome of gestation. Abrupt and dramatic decreases in total oestrogens, oestrone and oestradiol levels occurred during dexamethasone injections into intact and oophorectomized pregnant monkeys but no significant changes in progesterone levels in plasma were observed. Spontaneous intra-uterine foetal death was accompanied by decrease in oestrogens, but no changes in the plasma levels of progesterone. In experimentally induced foetal death, the oestrogen and progesterone levels in plasma decreased prior to abortion. These data demonstrate the relative influence of the ovaries, adrenals and the placenta on the maternal plasma levels of oestrogens and progesterone in the pregnant rhesus monkey.

CONCENTRATIONS OF OXYTOCIN IN THE PLASMA AND AMNIOTIC FLUID OF RHESUS MONKEYS (MACACA MULATTA) DURING THE LATTER HALF OF PREGNANCY

1980 ◽  
Vol 84 (3) ◽  
pp. 473-478 ◽  
Author(s):  
M. D. MITCHELL ◽  
L. A. MOUNTFORD ◽  
R. NATALE ◽  
J. S. ROBINSON
Keyword(s):  
Amniotic Fluid ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Peripheral Plasma ◽  
Specific Radioimmunoassay ◽  
Serial Samples

A specific radioimmunoassay for oxytocin has been established with a sensitivity of 0·8 pg/tube. This assay has been applied to the measurement of oxytocin in serial samples of peripheral plasma and amniotic fluid from pregnant rhesus monkeys, collected at weekly intervals by venepuncture and amniocentesis. Concentrations of oxytocin in both fluids were generally low and showed no trends throughout the latter half of gestation.

STEROIDS IN THE AMNIOTIC FLUID OF THE RHESUS MONKEY (MACACA MULATTA)

1977 ◽  
Vol 73 (2) ◽  
pp. 355-363 ◽  
Author(s):  
J. R. G. CHALLIS ◽  
PHILLIDA HARTLEY ◽  
P. JOHNSON ◽  
J. E. PATRICK ◽  
J. S. ROBINSON ◽  
...  
Keyword(s):  
Rhesus Monkey ◽  
Amniotic Fluid ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Plasma Cortisol ◽  
Late Pregnancy ◽  
Maternal Plasma ◽  
Steroid Secretion ◽  
Adrenal Steroid ◽  
Oestrone Sulphate

SUMMARY Representative C21, C19 and C18 steroids have been measured in the amniotic fluid and maternal femoral plasma of rhesus monkeys during the last 50 days of pregnancy. The concentrations of cortisol, progesterone, androstenedione, oestrone and oestrone sulphate all increased in amniotic fluid before spontaneous parturition. In contrast, amniotic fluid oestradiol levels remained low and unchanged, and were always less than the concentrations in the maternal plasma. The changes in progesterone, cortisol and oestrone concentrations in amniotic fluid occurred independently of significant changes in the concentration of these steroids in the maternal plasma. Betamethasone administered to monkeys after day 150 of pregnancy suppressed amniotic fluid and maternal plasma cortisol. This treatment markedly suppressed the concentration of progesterone in amniotic fluid, but did not alter its concentration in maternal plasma. It is concluded that during late pregnancy in the rhesus monkey there is an increase in the concentration of some steroids in amniotic fluid independent of alterations in their concentrations in maternal plasma. These changes could reflect an increase in foetal adrenal steroid secretion.

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.

PROSTAGLANDINS IN THE PLASMA AND AMNIOTIC FLUID OF RHESUS MONKEYS DURING PREGNANCY AND AFTER INTRA-UTERINE FOETAL DEATH

1976 ◽  
Vol 71 (1) ◽  
pp. 67-76 ◽  
Author(s):  
M. D. MITCHELL ◽  
J. E. PATRICK ◽  
J. S. ROBINSON ◽  
G. D. THORBURN ◽  
J. R. G. CHALLIS
Keyword(s):  
Amniotic Fluid ◽  
Rhesus Monkeys ◽  
Late Pregnancy ◽  
Normal Pregnancy ◽  
Maternal Plasma ◽  
Foetal Death ◽  
Peripheral Vein ◽  
Normal Term ◽  
Prostaglandin F ◽  
Venous Plasma

SUMMARY Prostaglandin F (PGF) was measured in amniotic fluid, and 13,14-dihydro-15-keto-prostaglandin F2α (PGFM) was measured in maternal peripheral venous plasma and amniotic fluid of rhesus monkeys during late pregnancy. 13,14-Dihydro-15-keto-PGF2α was determined in the maternal peripheral venous plasma of two animals following intrauterine foetal death. The mean concentration of PGF and PGFM in amniotic fluid increased fourfold during the last 5 days of pregnancy. This increase was associated with an increase in the oestrone concentration in amniotic fluid and in maternal plasma. In normal pregnancy there was no increase in PGFM levels in the maternal peripheral vein, up to 1–2 days pre partum. After intra-uterine death, progesterone concentration in the maternal peripheral vein was unaltered, but oestrone and oestradiol declined. In plasma samples taken within 12 h of delivery, the concentration of PGFM was raised. It is concluded that an increase in prostaglandin production accompanies delivery at normal term, and at delivery past term following intra-uterine foetal death.

Maternal, Umbilical, Uterine and Amniotic Prostaglandin E and F2α Levels in Labour

1988 ◽  
Vol 16 (4) ◽  
pp. 280-285
Author(s):  
S. Sahmay ◽  
A. Coke ◽  
N. Hekim ◽  
T. Atasu
Keyword(s):  
Amniotic Fluid ◽  
Pregnant Women ◽  
Mechanism Of Action ◽  
Plasma Levels ◽  
Maternal Plasma ◽  
Prostaglandin E ◽  
Uterine Contractions ◽  
Human Labour ◽  
Prostaglandin F

This paper confirms the important role played by prostaglandins in the induction of uterine contractions and the initiation of human labour, although the exact mechanism of action in labour remains unclear. Seventeen pregnant women at term were studied. Of these nine were in labour and the remainder underwent elective section. Prostaglandin E and F2α levels were measured in maternal, umbilical and uterine plasma and amniotic fluid by radioimmunoassay. Levels of prostaglandin E were generally higher than prostaglandin F2α but they were significantly lower in maternal and uterine plasma. Levels of prostaglandin F2α were significantly higher in maternal plasma during labour. The highest levels of prostaglandin were found in amniotic fluid. Measurements indicate that the decreasing ratio of prostaglandin E/F2α is more important in the initiation of labour than absolute levels of either prostaglandin.

PRODUCTION OF THROMBOXANE B2 BY INTRA-UTERINE TISSUES FROM LATE PREGNANT RHESUS MONKEYS (MACACA MULATTA) IN VITRO

1978 ◽  
Vol 79 (1) ◽  
pp. 103-106 ◽  
Author(s):  
M. D. MITCHELL ◽  
B. R. HICKS ◽  
G. D. THORBURN ◽  
J. S. ROBINSON
Keyword(s):  
Caesarean Section ◽  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Late Pregnancy ◽  
Significant Trend ◽  
Thromboxane B2 ◽  
Decidua Basalis

The rates of production of thromboxane B2 in vitro by intra-uterine tissues obtained from late pregnant monkeys by Caesarean section have been determined. The general quantitative order of rates of production was decidua basalis = decidua parietalis > placenta > chorion > amnion = myometrium. Myometrial production of thromboxane B2 was greater at term than during late pregnancy; no other tissue showed a significant trend with advancing gestation. These data demonstrate that the production of thromboxane B2 by intra-uterine tissues from late pregnant monkeys is both qualitatively and quantitatively different from the production of prostaglandins described previously. It is suggested that prostaglandins rather than thromboxanes are more intimately involved in the onset of labour in the rhesus monkey.

SPECIFIC CHANGE IN THE DIRECTION OF PROSTAGLANDIN SYNTHESIS BY INTRA-UTERINE TISSUES OF THE RHESUS MONKEY (MACACA MULATTA) DURING LATE PREGNANCY

1978 ◽  
Vol 78 (3) ◽  
pp. 343-350 ◽  
Author(s):  
M. D. MITCHELL ◽  
L. CLOVER ◽  
G. D. THORBURN ◽  
J. S. ROBINSON
Keyword(s):  
Rhesus Monkey ◽  
Macaca Mulatta ◽  
Late Pregnancy ◽  
Prostaglandin Synthesis ◽  
Unit Weight ◽  
Prostaglandin E ◽  
Specific Change ◽  
Decidua Basalis ◽  
Prostaglandin F

The rates of production of prostaglandin E (PGE), prostaglandin F (PGF) and 13,14-dihydro-15-oxo-prostaglandin F (PGFM) by intra-uterine tissues from pregnant monkeys in vitro have been determined using a method of tissue superfusion. The amnion, chorion, placenta, decidua basalis, decidua parietalis and myometrium were obtained at Caesarean section during late pregnancy. Production of PGE by all tissues was significantly lower at term than during late pregnancy, whereas production of PGF by the amnion, chorion, decidua parietalis and myometrium was significantly greater. All tissues produced significantly more PGE than PGF and also, excepting the decidua basalis and decidua parietalis, more PGFM than PGF. Close to parturition the amnion was quantitatively (per unit weight) the major source of prostaglandins. It is suggested that a specific change in the direction of prostaglandin synthesis by intra-uterine tissues occurs near parturition in the rhesus monkey.

CONCENTRATIONS OF MELATONIN IN THE PLASMA OF THE RHESUS MONKEY (MACACA MULATTA)

1980 ◽  
Vol 84 (3) ◽  
pp. 489-494 ◽  
Author(s):  
G. JENKIN ◽  
M. D. MITCHELL ◽  
P. HOPKINS ◽  
C. D. MATTHEWS ◽  
G. D. THORBURN
Keyword(s):  
Menstrual Cycle ◽  
Rhesus Monkey ◽  
Diurnal Variation ◽  
Lower Limit ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Cross Reactivity ◽  
Diurnal Variations ◽  
Peripheral Plasma

A radioimmunoassay for the determination of concentrations of melatonin in the plasma of rhesus monkeys has been developed. Antiserum for the assay was raised against N-acetyl serotonin and there was a 100% cross-reaction with melatonin. Cross-reactivity with closely related indoles, precursors and metabolites was less than or equal to 1%. The lower limit of sensitivity of the assay was 4 pg/tube. The assay has been used for the investigation of diurnal variations and cyclical changes in melatonin concentrations in peripheral plasma of the rhesus monkey. The concentrations of melatonin ranged between 26·6 and 85·3 pg/ml during sampling for 24 h.There was a distinct diurnal variation in the concentration of melatonin in plasma. The concentration during darkness (61·0 ± 7·1 (s.e.m.) pg/ml) was greater (P <0·01) than that during illumination (40·1 ± 6·1 pg/ml). There were no significant differences in the concentration of melatonin in plasma at any time during the 28 day menstrual cycle of the rhesus monkey.

INTRA-UTERINE TISSUES FROM LATE-PREGNANT RHESUS MONKEYS (MACACA MULATTA) PRODUCE 6-OXO-PROSTAGLANDIN F1α IN VITRO

1979 ◽  
Vol 81 (3) ◽  
pp. 339-343 ◽  
Author(s):  
M. D. MITCHELL ◽  
B. R. HICKS ◽  
G. D. THORBURN ◽  
J. S. ROBINSON
Keyword(s):  
Caesarean Section ◽  
Macaca Mulatta ◽  
Rhesus Monkeys ◽  
Late Pregnancy ◽  
Unit Weight ◽  
Decidua Basalis ◽  
Prostaglandin F ◽  
Near Term

The rates of production of 6-oxo-prostaglandin F1α (6-oxo-PGF1α) in vitro by intra-uterine tissues taken from late-pregnant monkeys at Caesarean section have been determined. For tissues obtained between days 140 and 149 of pregnancy (late pregnancy) the general quantitative order of rates of production (per unit weight) was decidua basalis> placenta > decidua parietalis>amnion>chorion = myometrium. When tissues were taken between days 160 and 168 of pregnancy (near term) this order was placenta > decidua parietalis = amnion> myometrium = decidua basalis > chorion. There was a significant reduction near term in the rate of production of 6-oxo-PGF1α by decidua basalis; all other tissues exhibited similar rates of production at the two gestational periods investigated.

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