scholarly journals Rate of ovarian progesterone secretion and peripheral plasma progesterone levels in unilaterally ovariectomized, pregnant rats

Reproduction ◽  
1982 ◽  
Vol 66 (2) ◽  
pp. 555-561 ◽  
Author(s):  
G. T. Meyer ◽  
N. W. Bruce
Keyword(s):  
Pregnant Rats ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Progesterone Secretion

The acute effect of placentectomy and hysterectomy on peripheral plasma progesterone levels and ovarian progesterone secretion in the pregnant rat

1983 ◽  
Vol 98 (1) ◽  
pp. 71-77 ◽  
Author(s):  
J. K. Olynyk ◽  
N. W. Bruce ◽  
B. J. Waddell
Keyword(s):  
Acute Effect ◽  
Initial Experiment ◽  
Direct Role ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Progesterone Secretion ◽  
And Control

The role of placental luteotrophins in modulating plasma progesterone concentrations and ovarian progesterone secretion was examined in 16-day pregnant rats. In an initial experiment rats were placentectomized and their plasma progesterone concentrations monitored for 24 h; the rats were conscious within 30 min of placentectomy. Relative to control values, progesterone concentrations fell significantly within 0·5 h. A venous outflow technique was then used to monitor rates of progesterone secretion from ovaries of hysterectomized and control rats maintained under anaesthesia. Hysterectomy had no apparent effect on either progesterone secretion or plasma progesterone concentrations for at least 2 h. A final experiment was carried out to compare the effects of hysterectomy on plasma progesterone concentrations in conscious rats with those of placentectomized rats of the first experiment. Progesterone concentrations did not change significantly in hysterectomized rats for 4 h but fell to very low values by 24 h. These results suggest that placental luteotrophins do not have an acute, direct role in the control of plasma progesterone levels but are needed to maintain progesterone secretion in the longer term and possibly inhibit uterine luteolysin release.

Independence of ovarian progesterone secretion rate from arterial progesterone concentrations in the pregnant rat

1982 ◽  
Vol 94 (1) ◽  
pp. 61-67 ◽  
Author(s):  
B. J. Waddell ◽  
N. W. Bruce ◽  
J. K. Olynyk
Keyword(s):  
Secretion Rate ◽  
Separate Experiment ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Plasma Progesterone ◽  
Progesterone Secretion ◽  
Fivefold Increase ◽  
The Face ◽  
Arterial Plasma ◽  
The Stability

We have sought to determine whether the rate of ovarian progesterone secretion in pregnant rats is inversely related to the arterial plasma progesterone concentrations. For this purpose, rates of ovarian progesterone secretion were measured on day 16 of pregnancy in seven progesterone-treated and eight untreated rats. Treated rats received once-daily s.c. injections of 63·6 μmol progesterone in peanut oil on days 13 to 16. In a separate experiment, this treatment was found to produce a relatively stable fivefold increase in plasma progesterone concentrations. The rate of ovarian blood flow was increased in treated animals (mean ± s.e.m.; treated, 0·63± 0·08 ml/min; untreated, 0·43± 0·08 ml/min) but the progesterone secretion rate was unchanged (treated, 1·13 ± 0·20 μmol/day per ovary; untreated, 1·05 ± 0·15 μmol/day per ovary). The stability of the progesterone secretion rate in the face of a fivefold increase in plasma progesterone concentration implies a lack of negative feedback from progesterone in plasma in the regulation of ovarian progesterone secretion.

MAINTENANCE OF PREGNANCY BY SYNTHETIC PROGESTAGENS IN GUINEA-PIGS OVARIECTOMIZED BEFORE IMPLANTATION; PROGESTERONE-BINDING PROTEIN AND PLACENTAL PROGESTERONE SECRETION

1972 ◽  
Vol 54 (3) ◽  
pp. 435-444 ◽  
Author(s):  
DOREEN V. ILLINGWORTH ◽  
RUTH DEANESLY
Keyword(s):  
Guinea Pigs ◽  
Binding Protein ◽  
Metabolic Clearance ◽  
Metabolic Clearance Rate ◽  
Plasma Progesterone ◽  
Experimental Animals ◽  
Peripheral Plasma ◽  
Melengestrol Acetate ◽  
Progesterone Secretion ◽  
Competitive Protein Binding

SUMMARY In guinea-pigs ovariectomized before implantation, pregnancy can be maintained during the first 3 or 4 weeks, a critical period of early growth, by synthetic progestagens that do not metabolize to progesterone (norgestrel, medroxyprogesterone acetate and melengestrol acetate). It follows that peripheral plasma progesterone levels are related to placental progesterone secretion. There were indications that progesterone secretion by the placenta begins as early as day 16–18 of pregnancy. In the experimental animals the plasma progesterone levels, measured by a competitive protein-binding technique, were 9·4 ± 2·07 ng/ml (mean ± s.e.m.; n = 18) by days 20–22 of pregnancy; they continued to rise and reached 26·4 ± 3·88 ng/ml (n = 8) by days 27 to 29. The metabolic clearance rate of progesterone measured in four pregnant ovariectomized animals with progesterone or progestagen implants, was < 10 l/day as in normal pregnant animals. The calculated production rates of progesterone in the experimental animals (0·1 to 0·35 mg/day) reflect the placental production rate of progesterone. A simple 'assay' is described for the high affinity progesterone-binding protein of pregnancy (progesteronebinding globulin).

ANASTOMOSIS OF THE UTERO—OVARIAN AND ANTERIOR MAMMARY VEINS FOR COLLECTION OF UTERO—OVARIAN VENOUS BLOOD: PROGESTERONE SECRETION RATES IN CYCLIC EWES

1971 ◽  
Vol 50 (2) ◽  
pp. 307-NP ◽  
Author(s):  
G. D. THORBURN ◽  
P. E. MATTNER
Keyword(s):  
Venous Blood ◽  
Venous Drainage ◽  
Venous Blood Flow ◽  
Normal Position ◽  
Jugular Veins ◽  
Direct Puncture ◽  
Plasma Progesterone ◽  
Peripheral Plasma ◽  
Progesterone Secretion ◽  
Secretion Rates

SUMMARY The ovarian and part of the uterine venous drainage was diverted through the superficial anterior mammary vein leaving the ovary in its normal position and preserving utero—ovarian relationships. The operation has been performed successfully in 18 pregnant Merino ewes (70–120 days' gestation). Blood samples were collected by direct puncture of the mammary and jugular veins during the latter half of pregnancy and the subsequent breeding season. All ewes lambed normally after a gestation period of 146–151 days. Twelve of the 16 surviving ewes resumed cyclic oestrous behaviour. Plasma progesterone concentration was measured by a competitive proteinbinding assay. Utero—ovarian venous blood flow and rates of ovarian progesterone secretion were measured throughout the oestrous cycle. Progesterone secretion during the luteal phase of the cycle was in the range of 4·5–6·0 mg/day. The progesterone concentrations in peripheral plasma were similar to those found in normal ewes.

PROGESTERONE IN THE HUMAN PERIPHERAL BLOOD IN THE PREOVULATORY PERIOD OF THE MENSTRUAL CYCLE

1967 ◽  
Vol 55 (1) ◽  
pp. 91-96 ◽  
Author(s):  
Benno Runnebaum ◽  
Josef Zander
Keyword(s):  
Menstrual Cycle ◽  
Corpus Luteum ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Progesterone Concentration ◽  
Plasma Progesterone ◽  
Progesterone Secretion ◽  
Graafian Follicle ◽  
The Mean ◽  
Mean Concentration

ABSTRACT Progesterone was determined and identified in human peripheral blood during the preovulatory period of the menstrual cycle, by combined isotope derivative and recrystallization analysis. The mean concentration of progesterone in 1.095 ml of plasma obtained 9 days before ovulation was 0.084 μg/100 ml. However, the mean concentration of progesterone in 1.122 ml of plasma obtained 4 days before ovulation was 0.279 μg/100 ml. These data demonstrate a source of progesterone secretion other than the corpus luteum. The higher plasma-progesterone concentration 4 days before ovulation may indicate progesterone secretion of the ripening Graafian follicle of the ovary.

PROPRANOLOL-BLOCKADE OF VASOPRESSIN INDUCED INCREASE IN PLASMA PROGESTERONE IN EARLY HUMAN PREGNANCY

1971 ◽  
Vol 66 (2) ◽  
pp. 283-288 ◽  
Author(s):  
Petter Fylling
Keyword(s):  
Cyclic Amp ◽  
Uterine Cervix ◽  
Adenosine Monophosphate ◽  
First Trimester ◽  
Blocking Agent ◽  
Simultaneous Administration ◽  
Plasma Progesterone ◽  
Human Pregnancy ◽  
Peripheral Plasma ◽  
Early Human

ABSTRACT Following continuous dilation of the uterine cervix or intravenous infusion of vasopressin during the first trimester of human pregnancy, a marked increase in the peripheral plasma progesterone levels was observed. This effect was blocked by simultaneous administration of propranolol (Inderal®), a β-blocking agent. It is suggested that both these stimulating and inhibiting effects might be related to 3′, 5′-adenosine monophosphate (cyclic AMP). The results indicate the existence of β-receptors in steroid producing tissues.

PLASMA PROLACTIN AND PROGESTERONE RESPONSES TO MATING ARE ALTERED IN AGED RATS

1981 ◽  
Vol 90 (2) ◽  
pp. 179-191 ◽  
Author(s):  
S. HENDRICKS ◽  
C. A. BLAKE
Keyword(s):  
Plasma Concentrations ◽  
External Jugular Vein ◽  
Female Rats ◽  
Plasma Prolactin ◽  
Aged Rats ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Plasma Progesterone ◽  
The One ◽  
The Right

The effects of varying amounts of copulatory stimulation on patterns of plasma concentrations of prolactin and progesterone were evaluated in 3- and 12-month-old female rats. The 12-month-old group included rats which still exhibited oestrous cycles and rats in persistent vaginal oestrus (PVO). The extent of copulatory stimulation was defined by the number of intromissions received during mating: ≤5,15 or > 50. Blood samples were drawn over the 8 days after mating through a cannula inserted into the right external jugular vein. Plasma from the samples was assayed for prolactin and progesterone. In aged but still cyclic rats, pregnancy rates were positively correlated with the number of intromissions received during mating. Only one rat in PVO became pregnant. All animals which became pregnant and rats in PVO which, after mating, exhibited a disruption of the pattern of PVO, showed the nocturnal surge of plasma prolactin characteristic of pregnant and pseudopregnant rats. While these surges persisted until day 8 after mating in pregnant animals, they were absent by this time in the rats in PVO. Prolactin surges were present in some but not all of the aged rats which did not become pregnant. Progesterone concentrations were raised in all pregnant animals except the one pregnant rat in PVO and, while not related to the number of intromissions, concentrations were higher 8 days after mating in young compared with those in aged pregnant rats. Plasma progesterone was low in rats in PVO regardless of disruption of the pattern of PVO. We have concluded that the failure of limited copulatory stimulation to induce pregnancy in older rats results, at least in part, from its failure to initiate nocturnal prolactin surges. Nevertheless, our data suggest that matings which are not experimentally limited should provide ample stimulation to establish such surges. Although reduced plasma concentrations of prolactin and progesterone at pro-oestrus and reduced plasma progesterone through part of gestation may contribute to decreasing fertility in aged rats, other unidentified factors appear to be involved in mediating the capacity of extensive copulatory stimulation to induce pregnancy in these animals.

Progesterone levels in peripheral plasma of Rocky Mountain bighorn ewes (Ovis canadensis) during the estrous cycle and pregnancy

1980 ◽  
Vol 58 (6) ◽  
pp. 1105-1108
Author(s):  
P. E. Whitehead ◽  
E. H. McEwan
Keyword(s):  
Estrous Cycle ◽  
Rocky Mountain ◽  
Ovis Canadensis ◽  
Rapid Decline ◽  
Plasma Progesterone ◽  
Peripheral Plasma

Plasma progesterone levels of three Rocky Mountain bighorn ewes (Ovis canadensis) were determined during anestrus, estrus, and pregnancy. Eighteen-month-old ewes had "silent" heats with peak progesterone levels ranging from 1.0 to 2.2 ng/mL. At [Formula: see text] years of age, luteal activity preceded behavioural estrus and successful breeding. During the first 50 days of gestation, plasma progesterone levels increased to 8.5 ng/mL (8.0–9.2 ng/mL). From 50 to 80 days, progesterone levels decreased, followed by an increase to peak values of 13.3 to 23.2 ng/mL. A rapid decline in progesterone levels occurred about the time of parturition.

PLASMA LEVELS OF OESTROGEN AND PROGESTERONE IN PREGNANT AND LACTATING HAMSTERS

1974 ◽  
Vol 63 (1) ◽  
pp. 125-135 ◽  
Author(s):  
RICHARD BARANCZUK ◽  
G. S. GREENWALD
Keyword(s):  
Plasma Levels ◽  
Post Partum ◽  
Ovarian Tissue ◽  
Foetal Death ◽  
Antral Follicles ◽  
Peripheral Plasma ◽  
Progesterone Secretion ◽  
Baseline Levels ◽  
The One ◽  
Normal Gestation

SUMMARY Oestrone (OE1), oestradiol (OE2) and progesterone were measured by radioimmunoassay in the same samples of peripheral plasma from pregnant and lactating hamsters. The levels of progesterone during most of pregnancy did not exceed the values found during the first 2 days of the oestrous cycle. However, on day 14 of pregnancy (2 days before parturition) the level of progesterone abruptly increased to 29 ng/ml and fell rapidly thereafter. Hysterectomy on day 12 of pregnancy resulted in baseline levels of progesterone ( < 2 ng/ml) on day 13 and no peak in progesterone comparable to the one observed on day 14 of normal gestation. Injecting progesterone on day 14 or later prolonged gestation and caused maternal and foetal death. Oestradiol concentration showed peaks on days 7 (67·3 pg/ml), 11 (117·6 pg/ml) and 14 (81·8 pg/ml) of pregnancy and dropped precipitously between days 14 and 16 of pregnancy. The highest values obtained on day 11 correlated with the maximal proliferation of antral follicles. The abrupt decline of oestrogen concentration at parturition is different from the pattern found in the mouse and rat but is consistent with the lack of post-partum ovulation in the hamster. Injecting 50–150 μg oestradiol cyclopentylpropionate between days 12 and 16 did not interfere with parturition by the morning of day 16. Oestrone was detectable throughout pregnancy; the levels were lower than for OE2. In general, the oestrogen patterns were parallel. During lactation, progesterone secretion remained relatively constant at about 10–11 ng/ml, presumably synthesized by the hypertrophied interstitium which is the dominant ovarian tissue. In most instances OE1 and OE2 were not detectable during lactation, consistent with the absence of antral follicles.

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