FOETAL AND MATERNAL PLASMA CONCENTRATIONS OF 13,14-DIHYDRO-15-OXO-PROSTAGLANDIN F IN THE MARE DURING LATE PREGNANCY AND AT PARTURITION

1978 ◽  
Vol 78 (2) ◽  
pp. 201-215 ◽  
Author(s):  
R. J. BARNES ◽  
R. S. COMLINE ◽  
L. B. JEFFCOTT ◽  
M. D. MITCHELL ◽  
P. D. ROSSDALE ◽  
...  

SUMMARY The concentrations of 13,14-dihydro-15-oxo-prostaglandin F (PGFM), the stable metabolite of prostaglandin F, were measured in the plasma of catheterized mares and foetuses and non-catheterized thoroughbred mares and ponies during the last months of gestation. The plasma concentration of PGFM increased gradually towards term in all groups of animals. During the operation for insertion of catheters, maternal and foetal concentrations of PGFM were high, but the values fell to basal levels 24–48 h after the operation. It was found that preoperative starvation (24 h) led to a rise in the concentration oef PGFM in th maternal plasma. The raised concentrations of PGFM during the operation were associated with low progestogen and high oestrogen concentrations in umbilical venous plasma. The subsequent survival period of the catheterized foal was inversely related to the maximum concentration of PGFM attained during the operation. Changes in the plasma concentration of PGFM were studied during normal parturition in thoroughbred mares, during oxytocin-induced delivery in non-catheterized ponies and during premature delivery or abortion in the catheterized animals. The greatest increase in the concentration of PGFM was seen in the thoroughbred animals during second-stage labour; oxytocin also resulted in a very rapid rise in the level of PGFM, which remained high until delivery. In the catheterized animals, the birth of live foetuses was associated with a rise in the concentration of PGFM in both foetal and maternal plasma during the last 2 h before delivery. Less consistent changes were found during abortion.

1975 ◽  
Vol 79 (3) ◽  
pp. 589-597 ◽  
Author(s):  
D. A. Johnson ◽  
P. A. Manning ◽  
J. F. Hennam ◽  
J. R. Newton ◽  
W. P. Collins

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.


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

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.


1987 ◽  
Vol 113 (1) ◽  
pp. 97-101 ◽  
Author(s):  
M. J. Taylor

ABSTRACT An inhibitor of 3β-hydroxysteroid dehydrogenase (3β-HSD) activity was administered to sheep in late pregnancy. A rapid fall in plasma progesterone concentrations followed, associated with premature delivery by all animals 44±3 h (s.e.m.) after administration of inhibitor. A significant (about twofold) increase in plasma concentrations of oestradiol-17β was detected immediately before delivery. These results demonstrate, in contrast to previous reports, that 3β-HSD inhibitors have the capacity consistently to induce premature delivery associated with increased oestrogen release in sheep. J. Endocr. (1987) 113, 97–101


1988 ◽  
Vol 116 (3) ◽  
pp. 381-385 ◽  
Author(s):  
T. M. Nguyen ◽  
A. Halhali ◽  
H. Guillozo ◽  
M. Garabedian ◽  
S. Balsan

ABSTRACT The effect of thyroparathyroidectomy (TPTX) on the plasma concentrations of the vitamin D metabolites (25-(OH)D, 24,25-(OH)2D and 1,25-(OH)2D) has been studied in pregnant rats and their fetuses during the last quarter of gestation. Maternal and fetal vitamin D metabolites were not significantly affected by TPTX. A significant increase in plasma 1,25-(OH)2D concentrations was observed in both TPTX and control mothers and fetuses from days 19 to 21. Fetal and maternal plasma 25-(OH)D were positively correlated in both control and TPTX groups. Such a correlation was also found for 24,25-(OH)2D in the two groups. In contrast, a positive correlation between maternal and fetal plasma concentrations of 1,25-(OH)2D was found in TPTX but not in control rats. These data suggest that major alterations in calcium metabolism, such as that produced by maternal TPTX, are insufficient to affect the changes in maternal and fetal plasma 1,25-(OH)2D during late pregnancy significantly. They also suggest that parathyroid hormone, thyroxine, and/or calcitonin may control a possible placental transfer of 1,25-(OH)2D in the rat. J. Endocr. (1988) 116, 381–385


1986 ◽  
Vol 111 (3) ◽  
pp. 469-475 ◽  
Author(s):  
E. M. Wintour ◽  
R. J. Bell ◽  
R. S. Carson ◽  
R. J. MacIsaac ◽  
G. W. Tregear ◽  
...  

ABSTRACT Synthetic ovine corticotrophin-releasing factor (oCRF) was infused continuously into the jugular veins of six ovine fetuses for 5–11 days. Two fetuses receiving 0·1 and 1·0 μg oCRF/h from gestational days 134 and 135 respectively, lambed prematurely on days 141 and 140 respectively. Three out of four fetuses receiving oCRF at 2·4 μg/h, from 125 days of gestation, delivered spontaneously at 131, 131 and 136 days, whilst one died in utero at 132 days. Two fetuses receiving vehicle only or oCRF intra-amniotically, were born at 148 and 145 days respectively, whilst six fetuses chronically cannulated but not infused were born at 149·8 ±2·1 (s.d.) days. In ewes lambing at term, maternal plasma progesterone concentrations were 41·4±11·4 (s.e.m.; n = 5), 28·8±7·8 (n = 6), 17·1 ±4·8 (n = 5) and 7·9± 1·1 (n = 4) nmol/l on 3, 2, 1 and 0 days respectively before the lambs were born. No such decrease in maternal plasma progesterone concentrations was seen in the oCRF-infused fetuses. Fetal plasma concentrations of immunoreactive ACTH were maintained above normal in oCRF-infused fetuses, but some desensitization to bolus oCRF injections occurred in these fetuses. Four of the five fetuses born prematurely were sufficiently mature to survive, being able to stand, breathe and suckle. It is concluded that continuous oCRF infusions into immature fetuses can accelerate maturation of a number of organs and systems culminating in the premature delivery of viable lambs. J. Endocr. (1986) 111, 469–475


1982 ◽  
Vol 92 (1) ◽  
pp. 85-93 ◽  
Author(s):  
M. J. TAYLOR ◽  
R. WEBB ◽  
M. D. MITCHELL ◽  
J. S. ROBINSON

The concentration of progesterone in the peripheral plasma of seven sheep during late pregnancy was reduced by injection of an inhibitor of 3β-hydroxysteroid dehydrogenase activity. Concentrations of progesterone were 10·0± 1·0(s.e.m.) ng/ml (n = 6) before injection of the inhibitor, fell to 1·39 ± 0·40 ng/ml (n = 6) 30 min after injection, and remained within this lowered range for 6 h after injection. By 20–24 h and 30–35 h after injection progesterone concentrations had recovered to 4·63±0·94 and 14·07 ±4·17 ng/ml respectively (n = 6). Six out of seven ewes delivered prematurely 32·5± 2·9 h after injection. Delivery appeared to be normal, and was associated with increasing concentrations of 13,14-dihydro-15-oxo prostaglandin F2α in peripheral plasma. Concentrations of oestradiol-17β17β in peripheral plasma were slightly raised immediately before delivery, at which time progesterone concentrations were within the preinjection range. These data suggest that progesterone withdrawal is one mechanism that initiates increased prostaglandin F2α secretion in the pregnant sheep.


1991 ◽  
Vol 261 (4) ◽  
pp. R995-R1002 ◽  
Author(s):  
M. Keller-Wood ◽  
C. E. Wood

In the sheep, maternal plasma adrenocorticotropic hormone and cortisol are increased in late pregnancy, and fetal plasma cortisol and adrenocorticotropic hormone rise precipitously in late gestation. To test whether the ovine placenta secretes corticotropin-releasing factor (CRF) into either the maternal or fetal circulation, pregnant ewes and their fetuses were prepared with femoral arterial catheters and uterine and umbilical venous catheters. Samples were taken from all sites before and during hypoxia. There was no difference in CRF concentration across the placenta in the mothers or the fetuses under resting or hypoxemic conditions, but maternal and fetal arterial plasma CRF concentrations increased between 128 and 145 days. In a second study, maternal and fetal femoral venous plasma CRF concentrations were measured 1-19 days before spontaneous parturition. The mean concentration increased 8.6 +/- 0.6 pg/ml 11-19 days before parturition to 13.0 +/- 1.0 and 13.2 +/- 1.4 pg/ml in fetuses 4-8 and 1-3 days before parturition, respectively. Maternal plasma concentrations did not significantly increase in the days closer to parturition. These studies demonstrate that there are low but measurable CRF concentrations in fetal and maternal sheep plasma but that these are not the result of tonic placental secretion of CRF.


1974 ◽  
Vol 63 (3) ◽  
pp. 557-570 ◽  
Author(s):  
D. V. ILLINGWORTH ◽  
J. R. G. CHALLIS ◽  
N. ACKLAND ◽  
A. M. BURTON ◽  
R. B. HEAP ◽  
...  

SUMMARY Parturition in the guinea-pig is not preceded by any consistent change in the maternal plasma concentrations of progesterone, total unconjugated oestrogens or corticosteroids, or by a significant change in the concentration of progesterone-binding globulin (PBG). The onset of parturition was delayed by high doses of oestrogens (stilboestrol and oestradiol), but was not affected by oestriol or an antiserum raised against oestradiol. Premature parturition was achieved by the intra-carotid infusion of adrenocorticotrophin or prostaglandins (PGF2α, PGE2, I.C.I. 80,996) in conscious animals with indwelling catheters. I.C.I. 80,996, a potent analogue of PGF2α, induced parturition in all seven guinea-pigs treated; delivery occurred within 6 h of starting the infusion in six animals, and within 48 h in the seventh. The undesirable side-effects that accompanied treatment with PGF2α or PGE2 were not encountered with I.C.I. 80,996. Parturition induced experimentally resembled normal delivery but was not preceded by any significant change in the maternal levels of progesterone, total unconjugated oestrogens, corticosteroids, PBG or CBG in the circulation. Oxytocin was not detected until the delivery of the first foetus. Parturition was not induced by maternal or foetal injections of corticosteroids or dexamethasone. Earlier findings are confirmed that the foetal adrenal grows steadily throughout late pregnancy and, unlike the foetal lamb adrenal, undergoes no rapid phase of growth immediately before term. Foetal adrenal weight decreased relative to foetal body weight. The trigger for parturition in this species remains unidentified.


1987 ◽  
Vol 114 (2) ◽  
pp. 325-328 ◽  
Author(s):  
Y. Otsuki ◽  
E. Okamoto ◽  
I. Iwata ◽  
E. Nishino ◽  
N. Mitsuda ◽  
...  

ABSTRACT Changes in concentration of human atrial natriuretic peptide (hANP) in normal and toxaemic pregnancy were examined. The maternal plasma concentration of hANP increased gradually during normal pregnancy to a maximum of 20·0±2·4 pmol/l (mean ± s.e.m.) after week 36 of pregnancy. From week 20, the plasma concentrations of hANP were significantly higher than those in non-pregnant women (9·3±2·0 pmol/l). In toxaemia with hypertension, maternal plasma hANP levels were increased after week 26 of pregnancy (37·7±6·0 pmol/l) compared with those in normal gravida at the same time (17·1±1·6 pmol/l). Maternal plasma hANP levels in toxaemia only with oedema were not different from those in normal gravida. J. Endocr. (1987) 114, 325–328


2006 ◽  
Vol 18 (3) ◽  
pp. 357 ◽  
Author(s):  
Masatoshi Matsuzaki ◽  
John S. Milne ◽  
Raymond P. Aitken ◽  
Jacqueline M. Wallace

Overnourishing the adolescent sheep promotes rapid maternal growth at the expense of the gravid uterus. The growth of the placenta is impaired and results in the premature delivery of low-birthweight lambs. The present study details fetal adipose tissue development in these growth-restricted pregnancies. Singleton pregnancies were established by embryo transfer and, thereafter, adolescent ewes were offered a high (H; n = 12) or moderate (M; n = 14) level of a complete diet until necropsy on Day 131 of gestation. Fetal weight was lower (P < 0.001) in H compared with M groups. High maternal intake preserved brain and perirenal fat weight (P < 0.003), whereas relative weights of the heart, lungs, spleen and liver were unaltered. High nutrient intake resulted in significantly elevated maternal plasma concentrations of insulin, leptin, prolactin and glucose, no significant changes in fetal insulin, leptin or non-esterified fatty acids and attenuated fetal prolactin concentrations. Irrespective of nutritional intake, maternal plasma leptin, prolactin and glucose concentrations were negatively correlated with fetal weight and were positively correlated with fetal perirenal fat proportion (all P < 0.01). The mRNA expression for leptin, prolactin receptor and uncoupling protein (UCP) 1 in fetal perirenal fat was equivalent between groups, but, irrespective of maternal nutrition, UCP1 mRNA levels were negatively correlated with fetal weight (P < 0.01). Thus, overnourishing pregnant adolescent sheep preserves fat deposition in their growth-restricted fetuses, which may have implications for neonatal thermogenesis and for programming of postnatal adiposity.


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