Endocrine and fluid-balance responses to amniotic and allantoic fluid loss in sheep

1990 ◽  
Vol 259 (4) ◽  
pp. R745-R752 ◽  
Author(s):  
K. A. Dickson ◽  
S. B. Hooper ◽  
I. C. McMillen ◽  
R. Harding
Keyword(s):  
Amniotic Fluid ◽  
Fluid Balance ◽  
Arginine Vasopressin ◽  
Plasma Concentrations ◽  
Plasma Osmolality ◽  
Allantoic Fluid ◽  
Maternal Plasma ◽  
Fetal Plasma ◽  
Arterial Blood ◽  
Urine Production

Our aim was to determine fetal and maternal endocrine and fluid-balance responses to prolonged loss of amniotic and allantoic fluids in sheep. In seven sheep, amniotic and allantoic fluids were drained [379.1 +/- 20.1 (SE) ml/day] from 107 to 135.3 +/- 0.6 days of gestation (term: 145 days). The results from these sheep were compared with those from seven control sheep. Maternal water intake, urine production, and urine osmolality were not altered by fluid drainage, nor were fetal and maternal arterial blood gases, pH, or plasma osmolalities. Fluid drainage increased amniotic, but not allantoic, fluid osmolality. Maternal plasma cortisol concentration increased with fluid drainage, but maternal plasma concentrations of prolactin and arginine vasopressin were unchanged. Fluid drainage increased prolactin concentrations in fetal plasma and amniotic fluid, but fetal plasma concentrations of cortisol (hydrocortisone), arginine vasopressin, norepinephrine, and epinephrine were unchanged. Our results show that the fetus is capable of maintaining its plasma osmolality despite prolonged loss of fluid from its amniotic and allantoic sacs and that this is associated with alterations in the production rate and the composition of amniotic fluid.

Fetal recirculation of amniotic fluid arginine vasopressin

1986 ◽  
Vol 250 (3) ◽  
pp. E253-E258
Author(s):  
M. G. Ervin ◽  
M. G. Ross ◽  
R. D. Leake ◽  
D. A. Fisher
Keyword(s):  
Amniotic Fluid ◽  
Arginine Vasopressin ◽  
Urine Volume ◽  
Fetal Lung ◽  
Biologically Active ◽  
Base Line ◽  
Lung Fluid ◽  
Fetal Plasma ◽  
Urine Production ◽  
Fetal Urine

Amniotic fluid volume reflects a balance between fetal lung fluid and fetal urine production and fluid reabsorption via fetal swallowing. Arginine vasopressin (AVP) infusion decreases both fetal lung fluid and urine production and increases amniotic fluid osmolality and AVP concentration. In the present study we assessed the effect of amniotic fluid AVP injection on plasma AVP (n = 6) and renal function (n = 4) in chronically catheterized fetal lambs (X gestation = 130 days). Thirty minutes after addition of 25 micrograms of synthetic AVP into the amniotic cavity, mean +/- SE fetal plasma AVP increased from a base line of 2.7 +/- 0.2 to 14.6 +/- 3.4 pg/ml (P less than 0.01). One hundred and twenty minutes after injection, plasma AVP had increased to 26.9 +/- 5.7 pg/ml. Fetal urine volume did not change (0.78 +/- 0.01 ml/min) but significant increases in urine osmolality (169 +/- 19 to 315 +/- 25 mosm) and urine sodium (64 +/- 11 to 125 +/- 11 mueq/ml) were observed 120 min after AVP administration. In conclusion, amniotic fluid AVP levels can affect fetal plasma AVP concentration, and AVP absorbed from the amniotic fluid by the fetus remains biologically active.

Maternal dehydration-rehydration: fetal plasma and urinary responses

1988 ◽  
Vol 255 (5) ◽  
pp. E674-E679 ◽  
Author(s):  
M. G. Ross ◽  
D. J. Sherman ◽  
M. G. Ervin ◽  
R. Castro ◽  
J. Humme
Keyword(s):  
Glomerular Filtration Rate ◽  
Arginine Vasopressin ◽  
Filtration Rate ◽  
Urine Volume ◽  
Plasma Osmolality ◽  
Urine Osmolality ◽  
Fetal Plasma ◽  
Urine Production ◽  
The Impact ◽  
Observation Period

Pregnant women may be exposed to exercise, thermal, or gastrointestinal (hyperemesis) water loss, all of which commonly induce a greater than 10 mosmol increase in plasma osmolality. Although fetal osmolality is dependent on maternal osmolality, the impact of maternal dehydration and subsequent maternal rehydration on the fetus has not been explored. Five pregnant ewes with singleton fetuses (136 +/- 1 day) were water deprived for 36 h resulting in a significant increase in plasma osmolality (298 +/- 3.4 to 313 +/- 5.0 mosmol). In response to maternal dehydration, fetal plasma osmolality (297.0 +/- 4.1 to 309.3 +/- 4.1 mosmol), arginine vasopressin (AVP) levels (1.5 +/- 0.2 to 7.9 +/- 1.0 pg/ml), hematocrit (35.1 to 38.6%), and urine osmolality (161.3 +/- 10.7 to 348.9 +/- 21.9 mosmol) significantly increased. Subsequently, ewes were rehydrated over 4 h with intravenously infused 0.45% saline (20 ml.kg-1.h-1). In response to maternal rehydration, maternal and fetal plasma osmolality decreased to basal values (298.9 +/- 3.2 and 300.1 +/- 3.8 mosmol, respectively) and fetal glomerular filtration rate (1.72 +/- 0.30 to 3.08 +/- 0.66 ml/min) and urine volume significantly increased (0.33 +/- 0.02 to 0.71 +/- 0.13 ml/min). However, fetal hematocrit (37.4%), plasma AVP (3.1 +/- 0.9 pg/ml), and urine osmolality (255.4 +/- 28.8 mosmol) did not return to basal levels during the observation period. These results demonstrate fetal hyperosmolality, blood volume contraction, AVP secretion, and altered urine production in response to maternal dehydration. Despite maternal rehydration and normalization of maternal and fetal plasma osmolality, fetal endocrine and fluid responses are prolonged.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Renal, hormonal, and cardiovascular responses to chronic angiotensin I infusion in the ovine fetus

1997 ◽  
Vol 272 (6) ◽  
pp. R1912-R1917 ◽  
Author(s):  
K. M. Moritz ◽  
K. Tangalakis ◽  
E. M. Wintour
Keyword(s):  
Plasma Concentrations ◽  
Allantoic Fluid ◽  
Cardiovascular Responses ◽  
Urine Flow ◽  
Angiotensin I ◽  
Fetal Sheep ◽  
Arterial Blood ◽  
Urine Production ◽  
Fetal Urine ◽  
Ovine Fetus

Long-term infusion of angiotensin I (ANG I) into the ovine fetus has been shown to cause excess accumulation of fetal fluid in the allantoic compartment. It was hypothesized that this resulted from sustained increases in fetal urine production, and the hormonal basis was examined. ANG I (6.7 micrograms/h, n = 6) or isotonic saline (n = 6) was infused for 3 days into chronically cannulated ovine fetuses (112-122 days of gestation). ANG I caused an immediate and progressive increase in mean arterial blood pressure (from 42 +/- 2 to 57 +/- 4 mmHg), increased urine flow rate (from 15 +/- 3 to 48 +/- 8 ml/h), and increased glomerular filtration rate (from 97 +/- 15 to 146 +/- 24 ml/h), without significant changes in fetal plasma concentrations of aldosterone, atrial natriuretic factor (ANF), adrenocorticotropin, or cortisol. There were substantial increases in sodium and chloride excretion, due to both increased fetal urine concentrations and fetal urine flow, without significant changes in urine osmolality (from 134 +/- 9 to 147 +/- 12 mosmol/kg water). There were no significant changes in any parameter in the saline-infused fetuses. Neither amniotic or allantoic fluid volume was significantly changed by ANG I infusion, but allantoic fluid Cl- concentration increased significantly. The conclusions are that ANG I caused a diuresis and natriuresis in the fetal sheep independent of changes in cortisol or ANF.

Amniotic fluid ionic concentration in response to chronic fetal vasopressin infusion

1985 ◽  
Vol 249 (3) ◽  
pp. E287-E291
Author(s):  
M. G. Ross ◽  
M. G. Ervin ◽  
R. D. Leake ◽  
D. A. Fisher
Keyword(s):  
Amniotic Fluid ◽  
Arginine Vasopressin ◽  
Plasma Osmolality ◽  
Ionic Concentration ◽  
Saline Infusion ◽  
Third Trimester ◽  
Vasopressin Infusion ◽  
Fetal Plasma ◽  
Intravenous Infusions ◽  
Sodium And Potassium

Chronically prepared, third trimester fetal lambs were administered 72-h intravenous infusions of arginine vasopressin (AVP) (65 or 130 mU/kg h) or 0.9% saline. Saline infusion preceding the AVP infusion did not change amniotic fluid (AF) composition. During the AVP infusion, there were significant increases in amniotic fluid osmolality (278.8 +/- 4.9 to 302.1 +/- 4.5 mosm) and in sodium (122.7 +/- 3.3 to 135.3 +/- 3.6 meq/l) and potassium (9.7 +/- 2.6 to 13.8 +/- 1.3 meq/l) concentrations. Saline infusion after the AVP infusion resulted in return of AF osmolality, sodium, and potassium toward normal levels. Fetal plasma and amniotic fluid AVP levels measured by radioimmunoassay significantly increased during AVP infusion and decreased during the subsequent saline infusion. There were no changes in maternal or fetal plasma osmolality in response to AVP. These results suggest that fetal AVP released in response to intrauterine stress may alter the composition and osmolality of amniotic fluid in a reversible manner.

Short-term fluctuations in the concentration of cortisol and progesterone in fetal plasma, maternal plasma, and amniotic and allantoic fluids from sheep during late pregnancy

1981 ◽  
Vol 59 (3) ◽  
pp. 261-267 ◽  
Author(s):  
J. R. G. Challis ◽  
J. E. Patrick ◽  
Jill Cross ◽  
J. Workewych ◽  
E. Manchester ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Allantoic Fluid ◽  
Late Pregnancy ◽  
Maternal Plasma ◽  
Significant Rise ◽  
Short Term ◽  
Fetal Plasma ◽  
Two Fluids ◽  
Paired Samples ◽  
Steroid Profiles

Fluctuations in the concentrations of cortisol and progesterone in fetal plasma, maternal plasma, and amniotic and allantoic fluids were measured in samples taken at 10-min intervals over a 90-min period from three groups of sheep sampled at different times during late pregnancy. During the last 30 days of gestation there was a significant rise in the mean concentration of cortisol in fetal plasma and amniotic fluid and a significant correlation between the cortisol concentration in these two fluids. The concentration of cortisol in allantoic fluid exceeded that in amniotic fluid. The concentration of cortisol in fetal plasma varied in a pulsatile manner; however the coefficient of variation (CV) within animals was greater (36%) on days −11 to −20, relative to the day of parturition (day 0), than on days −21 to −30 or days −5 to 0 (15–19%). The CV values for cortisol in amniotic fluid and maternal plasma during the last 30 days of pregnancy were 20–50% and two to five times greater than the intraassay CV. The concentration of progesterone in amniotic fluid increased after day −20 but was not correlated with that in maternal plasma or fetal plasma. The concentrations of progesterone in paired samples of amniotic fluid and allantoic fluid were similar. The CV values for progesterone (18–34%) were similar in fetal and maternal plasma and amniotic fluid and did not change significantly during late pregnancy. Changes in the concentration of progesterone were unrelated to changes in cortisol. Interpretation of steroid profiles in fetal plasma and fluids through late pregnancy should take into account these short-term fluctuations in hormone concentrations.

Fetal-maternal fluid and electrolyte relations during chronic fetal urine loss in sheep

1992 ◽  
Vol 263 (4) ◽  
pp. F671-F679 ◽  
Author(s):  
M. E. Wlodek ◽  
R. Harding ◽  
G. D. Thorburn
Keyword(s):  
Phase 1 ◽  
Plasma Osmolality ◽  
Chronic Phase ◽  
Allantoic Fluid ◽  
Maternal Plasma ◽  
Late Gestation ◽  
Control Group ◽  
Osmotic Gradient ◽  
Fetal Plasma ◽  
Fetal Urine

Our aim was to determine the effects of prolonged removal of fetal urine during late gestation on fetal-maternal fluid and electrolyte relationships. We measured the volume and composition of fetal urine and amniotic and allantoic fluids and the composition of fetal and maternal plasma in sheep before and during continuous urine drainage, which began at 130 days of gestation and continued until the onset of labor; a control group was also studied. The response to fetal urine drainage occurred in two phases. In the "acute" phase (1-3 days), amniotic and allantoic fluid volumes decreased significantly, presumably due to their reabsorption into the fetal chorionic circulation or swallowing of amniotic fluid by the fetus. During the "chronic" phase, starting 3-5 days after urine drainage, a significant reversal in the transplacental osmotic gradient occurred due to a decrease in maternal plasma osmolality. During the entire drainage period (14.1 +/- 1.1 days, mean +/- SE, n = 5) at least 542 ml/day of water and 24 mmol/day of electrolytes passed from the mother into the fetal circulation and fetal plasma osmolality was unchanged. We conclude that, despite the loss of substantial water and electrolytes, the fetus is able to maintain its growth and fluid and electrolyte homeostasis by obtaining water and electrolytes initially from the amniotic and allantoic fluids and subsequently from its mother. The movement of water and electrolytes to the fetus would have been facilitated by the reversed transplacental osmotic gradient.

scholarly journals Distribution of alpha1-fetoprotein in fetal plasma, allantoic fluid, amniotic fluid and maternal plasma of cows

Reproduction ◽  
1979 ◽  
Vol 57 (1) ◽  
pp. 235-238 ◽  
Author(s):  
K. M. Smith ◽  
P. C. W. Lai ◽  
H. A. Robertson ◽  
R. B. Church ◽  
F. L. Lorscheider
Keyword(s):  
Amniotic Fluid ◽  
Allantoic Fluid ◽  
Maternal Plasma ◽  
Fetal Plasma

scholarly journals Pre-implantation exogenous progesterone and pregnancy in sheep. II. Effects on fetal-placental development and nutrient transporters in late pregnancy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Katherine M. Halloran ◽  
Emily C. Hoskins ◽  
Claire Stenhouse ◽  
Robyn M. Moses ◽  
Kathrin A. Dunlap ◽  
...  
Keyword(s):  
Amniotic Fluid ◽  
Corn Oil ◽  
Allantoic Fluid ◽  
Late Pregnancy ◽  
Maternal Plasma ◽  
Nutrient Transporters ◽  
Placental Development ◽  
Blastocyst Development ◽  
Fetal Plasma ◽  
Exogenous Progesterone

Abstract Background Administration of progesterone (P4) to ewes during the first 9 to 12 days of pregnancy accelerates blastocyst development by day 12 of pregnancy, likely due to P4-induced up-regulation of key genes in uterine epithelia responsible for secretion and transport of components of histotroph into the uterine lumen. This study determined if acceleration of blastocyst development induced by exogenous P4 during the pre-implantation period affects fetal-placental development on day 125 of pregnancy. Suffolk ewes (n = 35) were mated to fertile rams and assigned randomly to receive daily intramuscular injections of either corn oil vehicle (CO, n = 18) or 25 mg progesterone in CO (P4, n = 17) for the first 8 days of pregnancy. All ewes were hysterectomized on day 125 of pregnancy and: 1) fetal and placental weights and measurements were recorded; 2) endometrial and placental tissues were analyzed for the expression of candidate mRNAs involved in nutrient transport and arginine metabolism; and 3) maternal plasma, fetal plasma, allantoic fluid, and amniotic fluid were analyzed for amino acids, agmatine, polyamines, glucose, and fructose. Results Treatment of ewes with exogenous P4 did not alter fetal or placental growth, but increased amounts of aspartate and arginine in allantoic fluid and amniotic fluid, respectively. Ewes that received exogenous P4 had greater expression of mRNAs for SLC7A1, SLC7A2, SLC2A1, AGMAT, and ODC1 in endometria, as well as SLC1A4, SLC2A5, SLC2A8 and ODC1 in placentomes. In addition, AZIN2 protein was immunolocalized to uterine luminal and glandular epithelia in P4-treated ewes, whereas AZIN2 localized only to uterine luminal epithelia in CO-treated ewes. Conclusions This study revealed that exogenous P4 administered in early pregnancy influenced expression of selected genes for nutrient transporters and the expression of a protein involved in polyamine synthesis on day 125 of pregnancy, suggesting a ‘programming’ effect of P4 on gene expression that affected the composition of nutrients in fetal-placental fluids.

Increase in the concentration of immunoreactive endothelin in human pregnancy

1991 ◽  
Vol 129 (2) ◽  
pp. 301-307 ◽  
Author(s):  
I. Iwata ◽  
T. Takagi ◽  
K. Yamaji ◽  
O. Tanizawa
Keyword(s):  
Detection Limit ◽  
Amniotic Fluid ◽  
Vaginal Delivery ◽  
Umbilical Artery ◽  
Umbilical Vein ◽  
Plasma Concentrations ◽  
Late Pregnancy ◽  
Maternal Plasma ◽  
Fetal Plasma ◽  
The Mean

ABSTRACT Maternal plasma concentrations of immunoreactive endothelin (ir-ET) during pregnancy, labour and after birth were measured by radioimmunoassay. Concentrations of ir-ET in the umbilical artery, umbilical vein, amniotic fluid and neonatal urine were also examined. The mean (± s.e.m.) plasma ir-ET concentration in early pregnancy (4–7 weeks) was 13·7±0·5 pmol/l, which was significantly higher than that in non-pregnant women (5·9±0·3 pmol/l). During pregnancy, plasma ir-ET concentrations gradually decreased to a minimum of 11·5±0·4 pmol/l in weeks 20–23, and then increased again towards term (12·5±0·4 pmol/l after 36 weeks of pregnancy). In women undergoing vaginal delivery, the mean plasma ir-ET concentration (17·1±0·7 pmol/l) increased significantly, compared with that in late pregnancy. After delivery, the plasma ir-ET concentration decreased abruptly to 4·0±0·2 pmol/l on the first day. Plasma ir-ET concentrations in umbilical vessels were significantly higher than those in maternal plasma. In addition, concentrations in the umbilical artery were significantly higher than those in the umbilical vein in cases of vaginal delivery. Concentrations of ir-ET in amniotic fluid were much higher than those in maternal or fetal plasma. ir-ET concentrations in neonatal urine on day 1 after birth were below the detection limit (< 0·1 pmol/l) by radioimmunoassay in 70% of the cases examined but on day 5 after birth ir-ET was present at measurable concentrations in all cases. It is suggested that endothelin may act as a circulating hormone during pregnancy and labour in both maternal and fetal circulations. Journal of Endocrinology (1991) 129, 301–307

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