PARTURITION IN THE COW: ENDOCRINE CHANGES IN ANIMALS WITH CHRONICALLY IMPLANTED CATHETERS IN THE FOETAL AND MATERNAL CIRCULATIONS

1974 ◽  
Vol 63 (3) ◽  
pp. 451-472 ◽  
Author(s):  
R. S. COMLINE ◽  
L. W. HALL ◽  
R. B. LAVELLE ◽  
P. W. NATHANIELSZ ◽  
MARIAN SILVER
Keyword(s):  
Plasma Cortisol ◽  
Blood Gases ◽  
Late Pregnancy ◽  
Peripheral Circulation ◽  
Maternal Plasma ◽  
Cortisol Concentration ◽  
Abrupt Increase ◽  
Intravascular Catheters ◽  
Jersey Cows

SUMMARY Intravascular catheters were placed in the umbilical, uterine and maternal peripheral circulations of 16 Jersey cows between 240 and 260 days of gestation. Foetal plasma cortisol, blood gases and pH, and maternal plasma oestrogen, progesterone and cortisol were measured in ten animals during late pregnancy and throughout spontaneous parturition; all delivered live foetuses although parturition was earlier than normal and the placenta was generally retained. The gradual pre-partum rise in foetal plasma cortisol during the last week of gestation (from 10–20 ng/ml 7 days before parturition to 51 ± 5 ng/ml in the last 3 h before delivery) was much less marked than the abrupt increase immediately after birth when the cortisol concentration invariably doubled. Maternal plasma oestrogen rose from 0.35 ± 0.04 ng/ml to 1·20 ± 0.11 ng/ml during the week before parturition. Progesterone concentrations remained stable until a sudden fall 1–2 days before delivery. The slight alterations in maternal plasma cortisol during this period were not statistically significant. The maternal plasma oestrogen levels were higher in the uterine vein than in the periphery, whereas uterine venous progesterone concentrations were significantly lower than in the peripheral circulation.

Does the ovine placenta secrete ACTH under normoxic or hypoxic conditions?

1991 ◽  
Vol 260 (2) ◽  
pp. R389-R395 ◽  
Author(s):  
M. Keller-Wood ◽  
C. E. Wood
Keyword(s):  
Plasma Cortisol ◽  
Adrenocorticotropic Hormone ◽  
Late Pregnancy ◽  
Maternal Plasma ◽  
Late Gestation ◽  
Fetal Circulation ◽  
Fetal Plasma ◽  
Hypoxic Conditions ◽  
Ovine Placenta ◽  
Arterial Po2

In the sheep, maternal plasma cortisol is increased in late pregnancy, and fetal plasma cortisol and adrenocorticotropic hormone (ACTH) rise precipitously in late gestation. In many species, the placenta contains ACTH. These experiments were designed to test whether the ovine placenta contains ACTH and whether there is net secretion of ACTH by the uteroplacental unit into either the maternal or fetal circulation. Pregnant ewes and their fetuses were prepared with maternal and fetal arterial and uterine and umbilical venous catheters. Arterial and venous samples were taken from both sides of the placenta before and during hypoxia induced by the ewe breathing 9-11% O2, and arteriovenous (a-v) differences in ACTH, PO2, PCO2, and progesterone were analyzed. A positive a-v difference in PO2 (48.2 +/- 3.4 mmHg) and negative a-v differences in PCO2 and progesterone (-3.5 +/- 0.7 mmHg and -25 +/- 5 ng/ml, respectively) were found across the placenta in the ewe, and a positive a-v difference in PCO2 (4.8 +/- 0.9 mmHg) and negative a-v differences in PO2 and progesterone (-8.1 +/- 1.5 mmHg and -13 +/- 3 ng/ml, respectively) were found across the placenta in the fetus, indicating that the umbilical and uterine venous catheters were properly placed. Hypoxia decreased fetal and maternal arterial PO2 from 22.8 +/- 1.3 to 13.8 +/- 0.7 and from 98.8 +/- 3.3 to 37.0 +/- 2.6 mmHg, respectively, and increased fetal and maternal arterial ACTH immunoreactivity from 95 +/- 60 to 2,676 +/- 795 and from 149 +/- 21 to 275 +/- 88 pg/ml, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

CORRELATION OF PLASMA NON-CONJUGATED OESTRIOL AND PLASMA CORTISOL IN LATE HUMAN PREGNANCY

1979 ◽  
Vol 92 (3) ◽  
pp. 553-559 ◽  
Author(s):  
G. Reck ◽  
A. Renner ◽  
G. Sinns ◽  
M. Breckwoldt
Keyword(s):  
Plasma Cortisol ◽  
Life Time ◽  
Significant Negative Correlation ◽  
Maternal Plasma ◽  
Cortisol Concentration ◽  
Diurnal Variations ◽  
Human Pregnancy ◽  
Back Action ◽  
Low Cortisol ◽  
Free Plasma

ABSTRACT The present study concerns the diurnal variations of free plasma oestriol and their relationship to maternal plasma cortisol in late human pregnancy. Four pregnant women volunteered for the study. According to the half-life time of oestriol blood was drawn at intervals of 30 and 60 minutes, respectively, over a period of 24 hours. Free oestriol was measured by radioimmunoassay and cortisol was quantitated by a protein binding method. All patients exhibited a circadian rhytm for free oestriol with higher values in the evening and early night (14.4 ± 3.7 ng/ml) than in the morning (11.3 ± 2.3 ng/ml, P < 0.001). The course of oestriol followed plasma cortisol in a significant negative correlation (r = −0.566, P < 0.001). During the period of low cortisol concentration oestriol levels demonstrated the phenomenon of episodic secretion. The results suggest that the maternal adrenals predominantly regulate the circadian rhythm of free oestriol by a negative feed-back action on the foetal hypothalamus.

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.

Negative-feedback inhibition of fetal ACTH secretion by maternal cortisol

1987 ◽  
Vol 252 (4) ◽  
pp. R743-R748 ◽  
Author(s):  
C. E. Wood
Keyword(s):  
Plasma Cortisol ◽  
Feedback Inhibition ◽  
Plasma Renin ◽  
Maternal Plasma ◽  
Cortisol Concentration ◽  
Acth Secretion ◽  
Fetal Plasma ◽  
Plasma Cortisol Concentration ◽  
Subsequent Period ◽  
Arteries And Veins

Previous studies in this laboratory have shown that small increases in fetal cortisol (F) decreased basal fetal plasma renin activity (PRA) and completely inhibited the fetal adrenocorticotropin hormone (ACTH) response to hypotension. The present study was designed to quantitate suppression of fetal ACTH and renin secretion by maternal F. Fetal and maternal femoral arteries and veins were chronically catheterized (11 fetuses, 118-129 days gestation). Maternal intravenous infusion of 0, 0.5, 1.0, and 2.0 micrograms F X kg-1 X min-1 (n = 5-6) increased mean maternal and fetal cortisol and suppressed fetal ACTH responses to a subsequent period of hypotension in a dose-related manner. Increases in fetal plasma cortisol to 8.3 ng/ml completely suppressed the fetal ACTH response to hypotension. The results indicate that increases in maternal plasma cortisol concentration sufficient to produce modest increases in fetal plasma cortisol inhibit fetal ACTH secretion.

CHANGES IN THE COMPOSITION AND YIELD OF THE MAMMARY SECRETION OF COWS DURING THE INITIATION OF LACTATION

1973 ◽  
Vol 59 (2) ◽  
pp. 231-247 ◽  
Author(s):  
P. E. HARTMANN
Keyword(s):  
Mammary Gland ◽  
Late Pregnancy ◽  
The Other ◽  
Small Samples ◽  
Dry Period ◽  
Abrupt Increase ◽  
Milk Samples ◽  
Casein Protein ◽  
Two Phases

SUMMARY Mammary secretion (1·2–2·0 ml) was collected from the milk sinus of each mammary gland (quarter) of two pregnant heifers and eight pregnant cows (dry period 49–229 days), first at weekly intervals from 40 days before parturition, then with increasing frequency as parturition approached. The progressive changes in the concentration of lactose, glucose, casein, non-casein protein and fat in the mammary secretion were determined. Calves were separated from the cows immediately after birth and the yield and composition of milk from individual quarters were determined for 5 days after parturition. Two quarters (milked quarters) of each of a further five cows were milked throughout pregnancy, while the other two quarters (unmilked quarters) of each cow were allowed to involute (dry off) 63– 104 days before parturition. Small samples (5–10 ml) of secretion were collected from the unmilked quarters, first at weekly intervals after drying off and then every second day from 10 to 15 days before parturition. On the days that the unmilked quarters were sampled, corresponding composite milk samples were collected from the milked quarters and the progressive changes in the yield of milk, lactose and fat were determined. The changes in the concentration of lactose and glucose in the mammary secretion, during drying off in late lactation, were determined in an additional five cows. In most cows allowed a usual dry period, and in the unmilked quarters of cows in which two quarters were milked throughout pregnancy, the concentration of lactose gradually increased from about 8 to 12 days before parturition to reach levels of about half those found in normal milk just before parturition. However, in some cows the concentration of lactose was low until 1–2 days before parturition and then increased abruptly, whereas in others the concentration of lactose increased slowly from as early as 32 days before parturition. A further rapid increase in the concentration of lactose in the mammary secretion occurred between 0 and 4 days before parturition in all cows. This latter increase was accompanied by an abrupt increase in the yield of milk, lactose and fat in the milked quarters of the cows in which two quarters were milked throughout pregnancy. These observations suggest that the initiation of lactation in the cow develops in two phases, a limited secretion of milk constituents occurs in late pregnancy and then 0–4 days before parturition copious secretion (lactogenesis) occurs.

Intrauterine growth restriction delays surfactant protein maturation in the sheep fetus

2010 ◽  
Vol 298 (4) ◽  
pp. L575-L583 ◽  
Author(s):  
Sandra Orgeig ◽  
Tamara A. Crittenden ◽  
Ceilidh Marchant ◽  
I. Caroline McMillen ◽  
Janna L. Morrison
Keyword(s):  
Mrna Expression ◽  
Plasma Cortisol ◽  
Surfactant Protein ◽  
Cortisol Concentration ◽  
Plasma Catecholamine ◽  
Fetal Sheep ◽  
C Protein ◽  
Intrauterine Growth ◽  
Plasma Cortisol Concentration ◽  
The Impact

Pulmonary surfactant is synthesized by type II alveolar epithelial cells to regulate the surface tension at the air-liquid interface of the air-breathing lung. Developmental maturation of the surfactant system is controlled by many factors including oxygen, glucose, catecholamines, and cortisol. The intrauterine growth-restricted (IUGR) fetus is hypoxemic and hypoglycemic, with elevated plasma catecholamine and cortisol concentrations. The impact of IUGR on surfactant maturation is unclear. Here we investigate the expression of surfactant protein (SP) A, B, and C in lung tissue of fetal sheep at 133 and 141 days of gestation (term 150 ± 3 days) from control and carunclectomized Merino ewes. Placentally restricted (PR) fetuses had a body weight <2 SD from the mean of control fetuses and a mean gestational PaO2<17 mmHg. PR fetuses had reduced absolute, but not relative, lung weight, decreased plasma glucose concentration, and increased plasma cortisol concentration. Lung SP-A, -B, and -C protein and mRNA expression was reduced in PR compared with control fetuses at both ages. SP-B and -C but not SP-A mRNA expression and SP-A but not SP-B or -C protein expression increased with gestational age. Mean gestational PaO2was positively correlated with SP-A, -B, and -C protein and SP-B and -C mRNA expression in the younger cohort. SP-A and -B gene expression was inversely related to plasma cortisol concentration. Placental restriction, leading to chronic hypoxemia and hypercortisolemia in the carunclectomy model, results in significant inhibition of surfactant maturation. These data suggest that IUGR fetuses are at significant risk of lung complications, especially if born prematurely.

ANTIDIURETIC HORMONE AND CORTICOTROPHIN RELEASE IN MAN

1960 ◽  
Vol 21 (2) ◽  
pp. 171-176 ◽  
Author(s):  
S. SHUSTER
Keyword(s):  
Antidiuretic Hormone ◽  
Plasma Cortisol ◽  
Cortisol Concentration ◽  
Release Factor ◽  
Similar Increase ◽  
Rapid Infusion ◽  
Experimental Procedure ◽  
Plasma Cortisol Concentration ◽  
Corticotrophin Release Factor ◽  
Patients With Diabetes

SUMMARY Plasma cortisol concentrations increased after injections of nicotine. This increase was variable and was no greater than that seen after substitution of normal saline for nicotine. Plasma cortisol concentrations did not increase after nicotine in patients with hypopituitarism and after inhibition of corticotrophin release with triamcinolone. It is concluded that the increased plasma cortisol concentration after injection of nicotine was due to non-specific pituitary stimulation associated with the experimental procedure and not due to any direct effect of the nicotine. Nicotine resulted in a similar increase in plasma cortisol in four patients with diabetes insipidus. Neither rapid infusion of hypertonic mannitol nor ingestion of ethanol had a consistent effect on the plasma cortisol concentration. It is therefore concluded that the antidiuretic hormone is not the 'corticotrophin release factor' in man.

Seasonal variation in plasma cortisol concentration during pregnancy and the puerperium

1980 ◽  
Vol 8 (5) ◽  
pp. 587-588 ◽  
Author(s):  
JUDITH M. BAKER ◽  
SHEILA L. HANDLEY ◽  
GILL WALDRON ◽  
T. LESLIE DUNN
Keyword(s):  
Seasonal Variation ◽  
Plasma Cortisol ◽  
Cortisol Concentration ◽  
Plasma Cortisol Concentration
Sign in / Sign up

Export Citation Format

Share Document