Effect of maternal glucocorticoid treatment on ovine fetal fluids at 0.6 gestation

1995 ◽  
Vol 7 (6) ◽  
pp. 1595 ◽  
Author(s):  
K Tangalakis ◽  
K Moritz ◽  
L Shandley ◽  
EM Wintour
Keyword(s):  
Prolonged Exposure ◽  
Allantoic Fluid ◽  
Urine Flow ◽  
Dexamethasone Treatment ◽  
Glucocorticoid Treatment ◽  
51Cr Edta ◽  
Group 3 ◽  
Ovine Fetal ◽  
Bovine Type ◽  
Fetal Fluids

This study examined the effects of maternal dexamethasone treatment on the volume and composition of fetal fluids, and on placental morphology at 0.6 gestation (80-90 days). Nine pregnant ewes were infused with dexamethasone (D, 0.76 mg h-1 for 72 h) while an additional nine ewes received saline (S, 0.38 mL h-1 for 72 h). Allantoic fluid (ALF) volume was significantly greater (P < 0.01) in the D group (737 +/- 116 mL) than in the S group (190 +/- 55 mL), but there was no difference in amniotic fluid (AMF) volume. The urine flow rate was 11 times higher in three D fetuses. The 51Cr-EDTA infused into the bladders of four fetuses during the final 4-5 h of the 72 infusions was detected in both AMF and ALF. Dexamethasone treatment significantly altered the composition of the fetal fluids but had no affect on fetal body weight, organ weights and placental weight; however, there were fewer cotyledons under 5 g (P < 0.05). In the D group, 3% of cotyledons were of the 'bovine' type in morphology, whereas all cotyledons in the S group were of the 'ovine' type. These findings suggest that prolonged exposure to large doses of glucocorticoids during pregnancy would affect the volume and composition of the fetal fluids and placental morphology, with potentially detrimental effects on the fetus.

Effect of maternal glucocorticoid treatment on fetal fluids in sheep at 0.4 gestation

1994 ◽  
Vol 266 (4) ◽  
pp. R1174-R1181 ◽  
Author(s):  
E. M. Wintour ◽  
D. Alcorn ◽  
A. McFarlane ◽  
K. Moritz ◽  
S. J. Potocnik ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Flow Rate ◽  
Allantoic Fluid ◽  
Urine Flow ◽  
Fluid Volume ◽  
Fluid Composition ◽  
Glucocorticoid Treatment ◽  
Amniotic Fluid Volume ◽  
Fetal Urine ◽  
Fetal Fluids

Treatment of nine pregnant Merino ewes (64.0 +/- 0.4 days of gestation) with dexamethasone (D; 0.76 mg/h for 48 h) resulted in significant alterations in fetal fluids compared with eight saline-infused control animals (S; 63.0 +/- 0.9 days). There was a substantial increase in allantoic fluid volume (177 +/- 18 ml, D vs. 31 +/- 6, S) but no change in amniotic fluid volume (248 +/- 12 ml, D; 305 +/- 24, S). For allantoic fluid there was a significant decrease in osmolality (213 +/- 4 mosmol/kg water, D; 230 +/- 5, S) and alterations in composition. Amniotic fluid osmolality was unchanged (292 +/- 2 mosmol/kg water, D; 293 +/- 1, S), but amniotic fluid composition was affected. In four fetuses in which bladder and amniotic cannulas were inserted at gestational age 68-75 days, fetal urine flow rate increased from a mean of 4.1 +/- 1.1 to 13.8 +/- 2.6 ml/h after 24 h and 11.8 +/- 3.0 ml/h at 48 h for a similar maternal D infusion, whereas no such increase occurred in four control fetuses. All the fetal urine voided during a 3.5- to 4-h infusion of 51Cr-labeled EDTA into the fetal bladder was directed to the allantois. The results suggest that the increase in allantoic fluid volume resulted from increased fetal urine output into the allantoic compartment, although the composition of the excess allantoic fluid differed substantially from that of fetal urine. There was a greater incidence of abnormal cotyledons in the D-infused ewes.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of maternal glucocorticoid treatment on ovine fetal fluids at 0.6 gestation

Placenta ◽  
1994 ◽  
Vol 15 (7) ◽  
pp. A69
Author(s):  
K. Tangalakis ◽  
K. Moritz ◽  
S. Potocnik ◽  
L. Shandley ◽  
E.M. Wintour
Keyword(s):  
Glucocorticoid Treatment ◽  
Ovine Fetal ◽  
Fetal Fluids

HORMONAL CONTROL OF AMNIOTIC AND ALLANTOIC FLUID VOLUME IN OVARIECTOMIZED SHEEP

1968 ◽  
Vol 41 (4) ◽  
pp. 477-485 ◽  
Author(s):  
G. ALEXANDER ◽  
D. WILLIAMS
Keyword(s):  
Ovarian Tissue ◽  
Allantoic Fluid ◽  
Hormonal Control ◽  
Fluid Volume ◽  
Corpora Lutea ◽  
Dose Ratio ◽  
Oestradiol Benzoate ◽  
Bovine Type ◽  
Excessive Accumulation

SUMMARY In pregnant ewes, ovariectomized 3 weeks after mating and maintained with progesterone (7 mg./day) injected intramuscularly, there was excessive accumulation of allantoic fluid after 2 months of gestation. The addition of oestradiol benzoate (5 μg./day) or an increase in the dose of progesterone reduced the allantoic fluid volume to normal; this reduction depended on the dose of oestrogen and on the dose ratio of oestrogen to progesterone. Whilst oestrogen reduced allantoic fluid volume to normal, it increased the incidence of 'bovine' type of cotyledons which are not normally seen in ewes 2 months pregnant. The large allantoic volumes were apparently due to the absence of luteal rather than other ovarian tissue, since large volumes were also present in ewes maintained on 7 mg. progesterone/day after corpora lutea had been surgically expressed from the ovaries left in situ. Embryonic survival was adversely affected when corpora lutea were removed from the ovaries, but there was no clear effect on the morphology of cotyledons.

Collagen in the fetal membranes of sheep: changes throughout gestation and effects of dexamethasone at 60 days

1997 ◽  
Vol 9 (4) ◽  
pp. 455 ◽  
Author(s):  
Lynne Shandley ◽  
Karen M. Moritz ◽  
Chrishan S. Samuel ◽  
E. Marelyn Wintour
Keyword(s):  
Gel Electrophoresis ◽  
Normal Development ◽  
Allantoic Fluid ◽  
Dry Weight ◽  
Collagen Content ◽  
Fetal Membranes ◽  
Dexamethasone Treatment ◽  
Collagen Types ◽  
Volume Changes ◽  
Volume Increase

The tensile strength of fetal membranes is largely due to their collagen content. In this study we have examined the changes in collagen in the amniotic and allantoic membranes of the sheep over a wide gestational range (27–142 days of gestation; term, 145–150 days). The results have been correlated with volume changes in normal development, and in particular, the changes in allantois have been studied after a rapid and extensive increase in allantoic volume, as a result of maternal dexamethasone treatment (0·76 mg h-1 for 48 h) from Day 60 of gestation. Electron microscopy and immunohistochemistry were used to delineate collagen distribution, and gel electrophoresis was used to assess the relative proportions of each type. In the amnion, collagen content increased from 37±4% to 50±1% dry weight of the tissue from 41–102 days and declined slightly thereafter. In the allantois, collagen content increased from 20±1% at Day 27 to 50±6% at Day 142, significantly correlated with a volume increase from 253 mL to 813±274 mL. Collagen types I (>85%), III (10%) and small amounts of types IV and V (<5%) were identified in both membranes at all ages. When allantoic fluid volume was increased rapidly by maternal dexamethasone infusion, there was a significant decrease in collagen content from 38±6% to 25±2% (P < 0·05). By immunohistochemistry it was observed that both epithelial cells and fibroblasts were synthesizing collagen.

Renal function in the chronically cannulated fetal llama: comparison with studies in the ovine fetus

1995 ◽  
Vol 7 (5) ◽  
pp. 1311 ◽  
Author(s):  
EM Wintour ◽  
R Riquelme ◽  
C Gaete ◽  
C Rabasa ◽  
E Sanhueza ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Flow Rate ◽  
Urine Flow ◽  
Urine Flow Rate ◽  
Fetal Kidney ◽  
Fetal Plasma ◽  
Post Surgery ◽  
Fetal Urine ◽  
Ovine Fetus ◽  
Ovine Fetal

Samples of maternal and fetal plasma, fetal urine, and amniotic fluid were collected from 8 chronically cannulated pregnant llamas, in the last third of gestation. The samples were obtained for up to 18 days post-surgery. Osmolality, sodium (Na), potassium (K), chloride (Cl), and urea were measured on 40 samples collected on days 1, 2, 3, 4-5, 6-7, 8-9, and 10-19. The osmolalities of maternal and fetal plasma, fetal urine and amniotic fluid, averaged over these 7 time periods, were, respectively, 312 +/- 2, 311 +/- 1, 484 +/- 14, and 317 +/- 1 mosmol kg-1. Values are given as mean +/- s.e. The major differences from fetal fluid values in the ovine fetus (from previously published values) were the higher osmolality and urea concentration of llama fetal urine. Urine flow rate measured in 6 fetuses, 4.5-6.5 kg body weight, was 5.8 +/- 0.4 mliter h-1; urea clearance rate was 55.5 +/- 11.8 mliter h-1. Glomerular filtration rate (GFR), measured with 51Cr-EDTA in 5 fetuses on 1-4 occasions, was 111.4 +/- 23.3 mliter h-1. Fractional reabsorptions (FR) of Na, K and Cl were 97.9 +/- 1, 75.9 +/- 13.5 and 97.7 +/- 0.4% respectively. The GFR (25 mliter kg-1 h-1) and urine flow rate (1 mL kg-1 h-1) were less than half and about one-tenth the respective values in ovine fetuses. As Na reabsorption is the major oxygen-consuming activity of the kidney, the llama fetal kidney requires only half the oxygen needed by the ovine fetal kidney to reabsorb the filtered sodium load. The reason for the formation of hypertonic, rather than hypotonic, urine in the fetal llama may be due to both greater morphological maturity of the kidney and the excretion of as yet unidentified osmotically active organic substances.

Ovine fetal adaptations to chronically reduced urine flow: preservation of amniotic fluid volume

1996 ◽  
Vol 81 (6) ◽  
pp. 2588-2594 ◽  
Author(s):  
Stephanie E. Mann ◽  
Mark J. M. Nijland ◽  
Michael G. Ross
Keyword(s):  
Amniotic Fluid ◽  
Plasma Osmolality ◽  
Urine Osmolality ◽  
Urine Flow ◽  
Fluid Volume ◽  
Fetal Plasma ◽  
Arterial Blood ◽  
Amniotic Fluid Volume ◽  
Fetal Urine ◽  
Ovine Fetal

Mann, Stephanie E., Mark J. M. Nijland, and Michael G. Ross.Ovine fetal adaptations to chronically reduced urine flow: preservation of amniotic fluid volume. J. Appl. Physiol. 81(6): 2588–2594, 1996.—Adequate amniotic fluid (AF) volume is maintained by a balance of fetal fluid production (lung liquid and urine) and resorption (swallowing and intramembranous flow). Because fetal urine is the principle source of AF, alterations in urine flow and composition directly impact AF dynamics. Intra-amniotic 1-desamino-8-d-arginine vasopressin (DDAVP) is rapidly absorbed into fetal plasma and induces a marked fetal urinary antidiuresis. To examine the effect of intra-amniotic- DDAVP-induced fetal urinary responses on AF volume and composition, six chronically prepared ewes with singleton fetuses (gestation 128 ± 2 days) were studied for 72 h after a single intra-amniotic DDAVP (50-μg) injection. After DDAVP, fetal urine osmolality significantly increased at 2 h (157 ± 13 to 253 ± 21 mosmol/kg) and remained elevated at 72 h (400 ± 13 mosmol/kg). Urinary sodium (33.0 ± 4.5 to 117.2 ± 9.7 meq/l) and chloride (26.0 ± 2.8 to 92.4 ± 8.1 meq/l) concentrations similarly increased. AF osmolality increased (285 ± 3 to 299 ± 4 mosmol/kgH2O), although there was no change in fetal plasma osmolality (294 ± 2 mosmol/kg). Despite a 50% reduction in fetal urine flow (0.12 ± 0.03 to 0.05 ± 0.02 ml ⋅ kg−1 ⋅ min−1at 2 h and 0.06 ± 0.01 ml ⋅ kg−1 ⋅ min−1after 72 h), AF volume did not change (693 ± 226 to 679 ± 214 ml). There were no changes in fetal arterial blood pressures, pH,[Formula: see text], or[Formula: see text] after DDAVP. We conclude the following. 1) Intra-amniotic DDAVP injection induces a prolonged decrease in fetal urine flow and increases in urine and AF osmolalities. 2) Despite decreased urine flow, AF volume does not change. We speculate that, in response to DDAVP-induced fetal oliguria, reversed intramembranous flow (from isotonic fetal plasma to hypertonic AF) preserves AF volume.

scholarly journals Follistatin concentrations in maternal and fetal fluids during the oestrous cycle, gestation and parturition in Merino sheep

Reproduction ◽  
2002 ◽  
pp. 259-265 ◽  
Author(s):  
◽  
Y Xia ◽  
T O'Shea ◽  
S Hayward ◽  
AE O'Connor ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Amniotic Fluid ◽  
Allantoic Fluid ◽  
Oestrous Cycle ◽  
Physiological Effects ◽  
Fetal Blood ◽  
Blood Samples ◽  
Merino Sheep ◽  
Human Menstrual Cycle ◽  
Fetal Fluids

The aim of this study was to investigate the changes in follistatin, an activin binding protein, during the oestrous cycle, gestation and parturition in ewes using a radioimmunoassay for total follistatin, which uses dissociating reagents to remove the interference of activin. Follistatin concentrations remained unchanged (2.7 +/- 0.2 ng ml(-1)) during the oestrous cycle and decreased as pregnancy progressed. Follistatin concentrations in allantoic fluid also decreased during gestation, whereas in amniotic fluid follistatin concentrations reached a peak at day 75 of gestation (9.8 ng ml(-1)) and had decreased to 4.4 ng ml(-1) at day 140. Follistatin concentrations in fetal blood (7.0 +/- 0.5 ng ml(-1)) did not change from day 50 to day 140 of gestation but were significantly higher than in matched maternal samples (3.1 +/- 0.3 ng ml(-1)). Circulating follistatin in ewes was significantly increased on the day of parturition (5.6 +/- 0.6 ng ml(-1)) compared with the days before parturition (2.7 +/- 0.4 ng ml(-1)), but had decreased by day 2 after birth. Blood samples from newborn lambs showed that plasma follistatin concentration (13.4 +/- 2.3 ng ml(-1)) was significantly higher than that of the mothers and remained high for at least 7 days after birth. These data support previous studies of the human menstrual cycle indicating that follistatin is not an endocrine signal from the ovary; however, in contrast to human pregnancies, follistatin concentrations in sheep decreased and become high only after or during parturition. This difference observed between species may reflect different physiological effects of follistatin or may be the result of measurement of different isoforms.

An Indirect Microimmunofluorescence Test for Detection of Chlamydial Antibodies in Ovine Fetal Fluids

1994 ◽  
Vol 6 (3) ◽  
pp. 315-320 ◽  
Author(s):  
T. P. Sanderson ◽  
A. A. Andersen ◽  
L. D. Miller ◽  
J. J. Andrew ◽  
B. H. Janke ◽  
...  
Keyword(s):  
Chlamydial Infection ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Rapid Test ◽  
Chlamydia Psittaci ◽  
Diagnostic Laboratory ◽  
Specific Antibodies ◽  
Ovine Fetal ◽  
Microimmunofluorescence Test ◽  
Fetal Fluids

The objective of this study was to evaluate an indirect microimmunofluorescence test (IMIF) for detection of Chlamydial antibodies in serum and/or thoracic fluids of aborted ovine fetuses. One hundred eighty-two ovine fetuses, including 64 fetuses from 40 ewes that were experimentally infected with an ovine abortion strain of Chlamydia psittaci at gestation days 90–100, 10 fetuses from 6 normal ewes, and 108 fetuses selected from those received at the Iowa Veterinary Diagnostic Laboratory, were evaluated in this study. Fetuses from experimentally infected ewes were examined 4–60 days after inoculation. The IMIF findings were compared with the results of complement fixation serology for Chlamydiae and concentrations of immunoglobulin (IgG). Chlamydiae-specific antibodies were detected by IMIF in 28 of 38 fetuses infected with C. psittaci. Elevated levels of IgG and IMIF titers ≥ 1:8 were consistent findings in ovine fetuses infected with Chlamydiae for more than 24 days. IgG levels and titers of Chlamydial antibodies increased with maturity of the fetus and duration of Chlamydial infection. Chlamydial antibodies were not detected with the complement fixation test. Fluids from ovine fetuses aborted as a result of other causes also were examined, and IMIF results were negative. The results of this study indicate that the IMIF is a useful and relatively rapid test for identification of Chlamydial antibodies in ovine fetuses.

Oestrogens in fetal and maternal fluids throughout pregnancy in the pig and comparisons with the ewe and cow

1985 ◽  
Vol 106 (3) ◽  
pp. 355-360 ◽  
Author(s):  
H. A. Robertson ◽  
R. J. Dwyer ◽  
G. J. King
Keyword(s):  
Early Pregnancy ◽  
Allantoic Fluid ◽  
Maternal Blood ◽  
Maternal Plasma ◽  
Maternal Urine ◽  
Oestrone Sulphate ◽  
Fetal Fluids

ABSTRACT In order to correlate the concentrations of oestrogens in the fetal fluids of the pig with those observed in the maternal blood and urine, changes in the concentrations of oestrone, oestradiol-17β, oestrone sulphate, oestradiol sulphates and oestrone glucuronide were assessed throughout pregnancy in the fetal and maternal fluids. In general, the pattern of change was similar for all oestrogens measured in both fetal and maternal fluids. Since the concentration of oestrogens in allantoic fluid during early pregnancy is reflected in the concentration of these steroids in maternal plasma and excreted in the maternal urine, the rise and fall of oestrogen concentrations around day 30 is suggestive of synthesis followed by a virtual cessation of oestrogen production until the fetus or placenta again produce increasing amounts detectable after day 45. These findings contrast sharply with those in the cow and the ewe where, although similar peaks in oestrogen concentrations are observable in allantoic fluid during early pregnancy, they are not reflected in blood. J. Endocr. (1985) 106, 355–360

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