Early pregnancy factor in marsupials

2006 ◽  
Vol 54 (3) ◽  
pp. 211 ◽  
Author(s):  
Y. P. Cruz ◽  
H. Morton ◽  
A. C. Cavanagh ◽  
L. Selwood ◽  
S. D. Wilson ◽  
...  
Keyword(s):  
Early Pregnancy ◽  
Luteal Phase ◽  
Peripheral Circulation ◽  
Monodelphis Domestica ◽  
Laboratory Model ◽  
Physiological Changes ◽  
Early Pregnancy Factor ◽  
Plasma Progesterone ◽  
Sminthopsis Macroura

Maternal recognition of pregnancy in marsupials occurs in more subtle ways than it does in eutherians. For instance, unlike in eutherians, the plasma progesterone profiles of pregnant and non-pregnant animals are similar during the luteal phase. It is typically during the brief luteal phase that both gestation and parturition occur in marsupials. Yet histological and physiological changes have been documented between gravid and non-gravid uteri in certain monovular marsupials and between pregnant and non-pregnant animals in polyovular marsupials. Early pregnancy factor (EPF), a 10.8-kDa serum protein known to be homologous to chaperonin 10, is associated with maternal immunosuppression, embryonic development and pregnancy in eutherian mammals. It has been reported in two Australian marsupials: the dasyurid Sminthopsis macroura and the phalangerid Trichosurus vulpecula. This paper documents its occurrence in the New World didelphid Monodelphis domestica. EPF is detectable by rosette inhibition assay in the peripheral circulation of pregnant but not of non-pregnant or pseudopregnant animals. Our work focuses on the embryo–maternal signalling role of EPF during pregnancy. Because progesterone-driven changes are similar in pregnant and non-pregnant marsupials, these animals are an excellent laboratory model in which to investigate the role of EPF in orchestrating the physiological changes necessary to sustain pregnancy.

SEQUENTIAL CHANGES IN PLASMA PROGESTERONE IN THE COW DURING THE ESTROUS CYCLE, PREGNANCY, AT PARTURITION, AND POST-PARTUM

1972 ◽  
Vol 52 (4) ◽  
pp. 645-658 ◽  
Author(s):  
H. A. ROBERTSON
Keyword(s):  
Estrous Cycle ◽  
Early Pregnancy ◽  
Luteal Phase ◽  
Post Partum ◽  
Progesterone Concentration ◽  
Cyclic Activity ◽  
Gradual Decline ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Estrous Behavior

The progesterone concentration in peripheral plasma has been measured sequentially in individual cows during the estrous cycle, gestation, at parturition, and post-partum. During the estrous cycle the concentration was lowest just before, during, and just after estrus when the level (0.1–0.4 ng/ml) was similar to that found in three ovariectomized cows. The concentration commenced to rise on the 4th–6th day (day of estrus = 1st day), reached a peak of 3–6 ng/ml on the 11th–13th day, and dropped rapidly over a 24–48-hr period to a basal value 24–72 hr before the next estrus. In early pregnancy, the plasma progesterone concentration was similar to the maximum levels found during the luteal phase of the estrous cycle. Between 90 and 150 days there was an indication of a decline to a relatively low plasma progesterone concentration followed by a variable rise. Prior to parturition, there was a gradual decline over a period of 35–70 days reaching a level of <2.0 ng/ml the day before parturition. Following parturition, the level remained at <0.5 ng/ml until the first sign of the resumption of cyclic activity. The time for this to occur was very variable (20–>60 days). Although not conclusive, the evidence favors the view that for estrous behavior to occur, estrus must be preceded by luteal activity. The discharge of mucus can occur without previous luteal activity.

scholarly journals Leukotrienes modulate secretion of progesterone and prostaglandins during the estrous cycle and early pregnancy in cattle: an in vivo study

Reproduction ◽  
2010 ◽  
Vol 140 (5) ◽  
pp. 767-776 ◽  
Author(s):  
Anna J Korzekwa ◽  
Mamadou M Bah ◽  
Andrzej Kurzynowski ◽  
Karolina Lukasik ◽  
Agnieszka Groblewska ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Estrous Cycle ◽  
Early Pregnancy ◽  
Luteal Phase ◽  
Reproductive Tract ◽  
Cell Function ◽  
Ovarian Cell

Recently, we showed that leukotrienes (LTs) regulate ovarian cell functionin vitro. The aim of this study was to examine the role of LTs in corpus luteum (CL) function during both the estrous cycle and early pregnancyin vivo. mRNA expression of LT receptors (BLTfor LTB4andCYSLTfor LTC4), and 5-lipoxygenase (5-LO) in CL tissue and their localization in the ovary were studied during the estrous cycle and early pregnancy. Moreover, concentrations of LTs (LTB4and C4) in the CL tissue and blood were measured.5-LOandBLTmRNA expression increased on days 16–18 of the cycle, whereasCYSLTmRNA expression increased on days 16–18 of the pregnancy. The level of LTB4was evaluated during pregnancy compared with the level of LTC4, which increased during CL regression. LT antagonists influenced the duration of the estrous cycle: the LTC4antagonist (azelastine) prolonged the luteal phase, whereas the LTB4antagonist (dapsone) caused earlier luteolysisin vivo. Dapsone decreased progesterone (P4) secretion and azelastine increased P4secretion during the estrous cycle. In summary, LT action in the bovine reproductive tract is dependent on LT type: LTB4is luteotropic during the estrous cycle and supports early pregnancy, whereas LTC4is luteolytic, regarded as undesirable in early pregnancy. LTs are produced/secreted in the CL tissue, influence prostaglandin function, and serve as important factors during the estrous cycle and early pregnancy in cattle.

THE CONCENTRATION OF PROGESTERONE IN THE PERIPHERAL PLASMA OF THE PREGNANT EWE

1969 ◽  
Vol 45 (3) ◽  
pp. 449-457 ◽  
Author(s):  
J. M. BASSETT ◽  
TANA J. OXBORROW ◽  
I. D. SMITH ◽  
G. D. THORBURN
Keyword(s):  
Protein Binding ◽  
Early Pregnancy ◽  
Luteal Phase ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
High Concentrations ◽  
Pregnant Ewe

SUMMARY The progesterone concentration in the peripheral plasma of ewes throughout pregnancy has been determined by a protein-binding method. Plasma progesterone concentrations during the first 50 days of pregnancy (2–3 ng./ml.) were not significantly higher than peak concentrations during the luteal phase in cycling non-pregnant ewes, but there was no decrease in the concentration 15–20 days after mating as occurs in non-pregnant ewes. Between 50 and 120 days after mating the plasma progesterone concentration increased steadily to values 2–5 times that found in early pregnancy. These high concentrations were maintained until lambing. A decrease in progesterone concentration during the week preceding lambing was usually, but not always, observed. Mean plasma progesterone concentrations during the last 50 days of pregnancy in ewes with twins were approximately twice those in ewes with a single foetus.

scholarly journals Significance of serum early pregnancy factor concentrations during pregnancy and embryonic development in Sminthopsis macroura (Spencer) (Marsupialia: Dasyuridae)

Reproduction ◽  
2001 ◽  
pp. 933-939 ◽  
Author(s):  
YP Cruz ◽  
L Selwood ◽  
H Morton ◽  
AC Cavanagh
Keyword(s):  
Early Pregnancy ◽  
Experimental System ◽  
Immunohistochemical Analysis ◽  
Spatiotemporal Pattern ◽  
Secretory Cells ◽  
Early Pregnancy Factor ◽  
Pregnant Females ◽  
Physiological Adaptations ◽  
Sminthopsis Macroura ◽  
Maternal Recognition Of Pregnancy

Marsupial pregnancy differs from that in eutherians in duration, placentation and hormonal profile so much so that maternal recognition of pregnancy may not occur in polyovular marsupials. However, a comparison of gravid and non-gravid uteri reveals differences indicative of histological and physiological adaptations to pregnancy. In the present study, the hypothesis that embryo-maternal signalling occurs in polyovular marsupials was tested by examining serum from non-pregnant and pregnant Sminthopsis macroura for the presence of early pregnancy factor (EPF), a serum protein secreted by the ovary in response to the presence of a newly fertilized egg in the oviduct. EPF is detectable in the serum of pregnant, but not in non-pregnant, females in all eutherians studied to date. In the present study, EPF was detected in S. macroura serum by the rosette inhibition test during the first 9 days of the 10.7 day gestation period in this marsupial. However, EPF was not detected on day 10, just before parturition, or in non-pregnant or preovulatory animals. Immunohistochemical analysis of ovaries from gravid and non-gravid animals demonstrates that EPF is found in the capillaries, interstitial spaces and secretory cells of the corpus luteum. It is concluded that the spatiotemporal pattern of EPF activity described strongly indicates that maternal recognition of pregnancy in marsupials is mediated, at least in part, by EPF. Because the endocrinological milieu is the same in pregnant and non-pregnant marsupials, the possibility of using marsupials as an experimental system for studying EPF function unconfounded by hormonal effects is presented.

Role of plasma progesterone concentration in early pregnancy of the ewe

1981 ◽  
Vol 21 (113) ◽  
pp. 562 ◽  
Author(s):  
FD Brien ◽  
IA Cumming ◽  
IJ Clarke ◽  
CS Cocks
Keyword(s):  
Early Pregnancy ◽  
Progesterone Level ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Peripheral Plasma

Eighty-eight maiden and 125 mature Merino ewes were grazed on green irrigated pasture or given dry hay on a fallow area with or without a lupin grain supplement just before and during mating. Progesterone concentrations in peripheral plasma were measured at 12 d after coitus. Progesterone concentration was lower (2.27 vs 2.87 ng/ml, P < 0.001 ) when lupins were fed, and maiden ewes had higher progesterone concentrations than mature ewes (2.75 vs 2.36 ng/ml, P < 0.05). Pregnant ewes had higher progesterone concentrations than non-pregnant ewes (2.77 vs 2.36 ng/ml, P < 0.05), and ewes with two ovulations had higher progesterone concentrations than ewes with a single ovulation (3.13 vs 2.08 ng/ml, P < 0.001). There was an interaction between pasture type and lupin supplement, with lupins depressing progesterone level more on green irrigated pasture (lupins 2.11 ng/ml, no lupins 3.00 ng/ml, P < 0.05) than on dry pasture (lupins 2.45 ng/ml, no lupins 2.74 ng/ml, P < 0.05). The results confirm that a high plane of nutrition at mating lowers progesterone levels in plasma and suggest that this may be a factor in the increase in embryo deaths when ewes are fed lupin grain supplements.

EFFECT OF HCG ON PLASMA PROGESTERONE DURING THE LUTEAL PHASE OF THE MENSTRUAL CYCLE AND DURING PREGNANCY

1972 ◽  
Vol 69 (4) ◽  
pp. 739-746 ◽  
Author(s):  
B. Runnebaum ◽  
K. Holzmann ◽  
A.-M. Bierwirth-v. Münstermann ◽  
J. Zander
Keyword(s):  
Menstrual Cycle ◽  
Early Pregnancy ◽  
Luteal Phase ◽  
Late Pregnancy ◽  
Progesterone Level ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Healthy Women ◽  
Stimulation Experiments

ABSTRACT The influence of intravenous HCG infusions lasting for 2 hours on the peripheral plasma progesterone concentrations was investigated in healthy women on day 5 during the hyperthermic phase of the menstrual cycle and during week 6–19 and 31–39 of pregnancy. During the luteal phase the peripheral plasma progesterone level can be increased, on an average, up to 70 % with 5000 IU and up to 250 % with 20 000 IU. The highest plasma progesterone concentrations were reached about 8 hours after the beginning of the HCG infusion. In some experiments significantly elevated progesterone concentrations were still observed 20 hours after starting the HCG infusion. The results of intravenous HCG stimulation experiments during early pregnancy (10 000–20 000 IU) and during late pregnancy (5000–20 000 IU) showed no marked changes in the peripheral plasma progesterone concentrations.

scholarly journals Progesterone concentration in the marsupial Sminthopsis macroura: relationship with the conceptus, uterine glandular regeneration and body weight

Reproduction ◽  
2009 ◽  
Vol 137 (1) ◽  
pp. 107-117 ◽  
Author(s):  
E M Menkhorst ◽  
L A Hinds ◽  
L Selwood
Keyword(s):  
Body Weight ◽  
Mitotic Activity ◽  
Luteal Phase ◽  
Gestation Length ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Body Weights ◽  
Sminthopsis Macroura ◽  
Cell Arrest ◽  
First Time

Close examination of hormonal profiles and uterine morphology in the marsupial reproductive cycle highlights significant differences between pregnant and non-pregnant cycles. In the polyovular dasyurid marsupial Sminthopsis macroura, we identified changes associated with gestation by comparing ovarian and plasma progesterone concentrations, uterine weights, uterine epithelial mitoses, body weights and gestation lengths between pregnant and non-pregnant luteal phases. The plasma progesterone profile of S. macroura was biphasic, peaking during unilaminar blastocyst expansion and on the day of implantation. Periods of rapid embryonic development were associated with increasing plasma progesterone concentrations and animal body weight. For the first time in a polyovular marsupial, we identified 1) a correlation between ovarian progesterone concentration and conceptus number during the luteal phase just prior to implantation (total ovarian progesterone), indicating a conceptus influence on progesterone concentration; 2) a pulse of uterine epithelial mitotic activity at the time of implantation and 3) increased mitotic activity in pregnant animals during unilaminar blastocyst formation compared with non-pregnant animals. Gestation length was reduced by up to 15%, due to the loss of, or reduction in, the four-cell arrest and more rapid definitive blastocyst expansion. This is the first time a conceptus influence on gestation length has been identified in a dasyurid. This study provides further evidence for the modification of the luteal phase by pregnancy in S. macroura.

scholarly journals Monitoring and controlling reproduction in captive common marmosets on the basis of urinary oestrogen metabolites

1996 ◽  
Vol 30 (2) ◽  
pp. 162-170 ◽  
Author(s):  
C. Nievergelt ◽  
C. R. Pryce
Keyword(s):  
Early Pregnancy ◽  
Luteal Phase ◽  
Follicular Phase ◽  
Common Marmosets ◽  
Plasma Progesterone ◽  
Non Invasive ◽  
Routine Monitoring ◽  
Wide Range ◽  
Dose Dependent

Non-invasive methods for routine monitoring of reproductive states and reproduction control in large colonies of captive Callithrix jacchus have been developed. Immunoactive urinary oestrone-3-conjugates (E1C) were measured during non-conception cycles ( n=5) and pregnancy ( n=7). Using plasma progesterone levels to time ovulation, ovulation was quantitatively estimated by a) calculating the first E1C rise and b) by establishing an E1C threshold. Ovulation was thus defined as taking place 4 days preceding a) the first rise of E1C above follicular-phase levels, or b) a concentration 4≥.5 µg E1/mg creatinine. Early pregnancy could be determined after day 20 by continued luteal-phase levels of E1C. Secondly, the luteolytic effect of cloprostenol, injected over a wide range of doses and between days 1 and 64 after ovulation/conception, was analysed. Luteolysis was achieved when cloprostenol was administered after day 5 post-ovulation; the luteolytic effect was found not to be dose-dependent. The success of cloprostenol treatment was 87% as confirmed by endocrine monitoring. The methods described are effective and minimize intervention, and are therefore suitable for long-term applications, particularly in combination with behavioural studies.

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