Developmental changes of amino acids in ovine fetal fluids

We recently reported an unusual abundance of arginine (4-6 mM) in porcine allantoic fluid during early gestation. However, it is not known whether such high concentrations of arginine are unique for porcine allantoic fluid or whether they represent an important physiological phenomenon for mammals. The present study was conducted to test the hypothesis that arginine is also the most abundant amino acid in ovine allantoic fluid. Allantoic and amniotic fluids, as well as fetal and maternal plasma samples, were obtained from ewes between Days 30 and 140 of gestation. Glycine was the most abundant amino acid in maternal uterine arterial plasma, representing approximately 25% of total alpha-amino acids. Alanine, glutamine, glycine, plus serine contributed approximately 50% of total alpha-amino acids in fetal plasma. Fetal:maternal plasma ratios for amino acids varied greatly, being less than 1 for glutamate during late gestation, 1.5-3 for most amino acids throughout gestation, and greater than 10 for serine during late gestation. Marked changes were observed in amino acid concentrations in amniotic and allantoic fluids associated with conceptus development. Concentrations of alanine, citrulline, and glutamine in allantoic fluid increased by 20-, 34-, and 18-fold, respectively, between Days 30 and 60 of gestation and were 24.7, 9.7, and 23.5 mM, respectively, on Day 60 of gestation (compared with 0.8 mM arginine). Remarkably, alanine, citrulline, plus glutamine accounted for approximately 80% of total alpha-amino acids in allantoic fluid during early gestation. Serine (16.5 mM) contributed approximately 60% of total alpha-amino acids in allantoic fluid on Day 140 of gestation. These novel findings of the unusual abundance of traditionally classified nonessential amino acids in allantoic fluid raise important questions regarding their roles in ovine conceptus development.     

Decline in lung liquid volume and secretion rate during oligohydramnios in fetal sheep

Reduced amniotic fluid volume often results in fetal lung hypoplasia. Our aim was to examine the effects of prolonged drainage of amniotic and allantoic fluids on lung liquid volume (Vl), secretion rate (Vs), and tracheal flow rate (Vtr) in fetal sheep. In five experimental animals, amniotic and allantoic fluids were drained from 107 to 135 days of gestation. The volume of fluid drained from the experimental animals was 411.8 +/- 24.4 ml/day (n = 140). In six control animals, amniotic fluid volume was 747.7 +/- 89.7 ml (n = 15). Wet and dry lung weights were 20-25% lower in experimental fetuses than in control fetuses. Fetal hemoglobin, O2 saturation, arterial PO2, pH, and hematocrit were unchanged by drainage. During the drainage period, Vl was up to 65% lower, Vs was up to 35% lower, and Vtr was up to 40% lower in experimental fetuses than in control fetuses. We conclude that prolonged drainage of amniotic and allantoic fluids decreases Vl, Vs, and Vtr in fetal sheep. These findings indicate that fetal lung hypoplasia associated with oligohydramnios may be the result of a prolonged reduction in Vl.     

Bovine amniotic and allantoic fluids for the culture of murine embryos

This study evaluated bovine amniotic and allantoic fluids as culture media for two-cell murine embryos to the hatched blastocyst stage. Amniotic and allantoic fluids were collected from four 70-d periods of pregnancy and pooled from at least five different animals. In Experiment 1 (n = 470) the fluids were frozen twice. Treatments consisted of twice frozen amniotic or allantoic fluid from each pregnancy period, Whitten's medium and fetal calf serum. The later two media were controls. Twice-frozen amniotic fluid <70 d pregnancy period, fetal calf serum and Whitten's medium supported the development of embryos to the hatched blastocyst stage. Whitten's medium was superior to twice-frozen amniotic fluid <70 d pregnancy period or fetal calf serum (P<0.01). Biochemical analysis showed lower glucose in amniotic and allantoic fluids than in Whitten's medium. Experiment 2 (n = 425) was performed to evaluate the effect of glucose supplementation to amniotic fluid. No benefit of glucose supplementation of the amniotic fluid was observed. In Experiment 3 (n = 432), the fluids were transported nonfrozen on ice. Treatments consisted of nonfrozen amniotic fluid <70 d pregnancy period; nonfrozen amniotic fluid <70 d pregnancy period + glucose), nonfrozen allantoic fluid <70 d pregnancy period; and Whitten's medium. The percentages of embryos developing to hatched blastocyst stage were 66.6, 56.5, 57.4 and 63.9% respectively, for each of the four treatments. No differences were found between any two treatments (P<0.05). In Experiment 4 (n = 231) the fluids were stored at -20 degrees C for 15 d. Whitten's medium was superior to amniotic or allantoic fluid <70 d pregnancy period in sustaining embryo development (P<0.05). In conclusion, these data indicate that nonfrozen bovine amniotic or allantoic fluid <70 d pregnancy period can support the development of murine embryos to the hatched blastocyst stage comparable to culture in Whitten's medium. Glucose supplementation of the amniotic fluid offered no advantage, and freezing of fluids had an adverse effect on in vitro embryo development.     

Developmental changes in polyamine levels and synthesis in the ovine conceptus

Polyamines (putrescine, spermidine, and spermine) are essential for placental growth and angiogenesis. However, little is known about changes in polyamine synthesis associated with development of the ovine conceptus (embryo/fetus and associated placental membranes). We hypothesized that rates of placental polyamine synthesis were maximal during the rapid placental growth that occurs in the first half of pregnancy. This hypothesis was tested using ewes between Days 30 and 140 of gestation. Columbia cross-bred ewes were hysterectomized on Days 30, 40, 60, 80, 100, 120, or 140 of gestation (Day 0 = mating; n = 4 ewes/day) to obtain placentomes, intercotyledonary placenta, intercaruncular endometrium, and allantoic as well as amniotic fluids. The tissues were analyzed for ornithine decarboxylase (ODC) and arginase activities; arginine, ornithine, and polyamine concentrations; and polyamine synthesis using radiochemical and chromatographic methods. Maximal ODC and arginase activities and the highest rates of polyamine synthesis were observed in all tissues on Day 40 of gestation. Concentrations of ornithine and polyamines in placentomes and intercaruncular endometrium also peaked on Day 40 of gestation. In ovine allantoic and amniotic fluids, polyamines were most abundant during early (Days 40-60) and late (Days 100-140) gestation, respectively. Amniotic fluid spermine increased progressively with advancing gestation. Results of the present study indicate metabolic coordination among the several integrated pathways that support high rates of polyamine synthesis in the placenta and endometrium during early pregnancy. Our findings may have important implications for both intrauterine growth retardation and fetal origins of diseases in adults.     

Conjugated and unconjugated oestrogens in fetal and maternal fluids of the cow throughout pregnancy.

The changes in concentration of oestrone, oestradiol (-17alpha and -17beta), oestrone sulphate and the oestradiol sulphates have been measured in allantoic and amniotic fluids and in maternal peripheral plasma throughout gestation. Oestrone sulphate was the major oestrone present in all of the fluids. It was measurable in allantoic fluid before Day 52 and reached a peak concentration of 475 ng/ml around Day 133. A lower peak occurred in the amniotic fluid around Day 110. The changes in oestradiol sulphates in allantoic fluid were similar to those of oestrone sulphate but at a much lower level. Considerable fluctuation was observed in the oestradiol sulphate concentrations in amniotic fluid. The ratio of oestradiol-17alpha sulphate to oestradiol-17beta sulphate was considerably higher in amniotic fluid than in allantoic fluid. Consistent changes in the levels of oestrone and the oestradiols were found in amniotic fluid but not in allantoic fluid during the second half of pregnancy. In maternal peripheral plasma oestrone sulphate was measurable before Day 72. In the limited number of samples analysed no difference in oestrogen concentration due to the sex of the fetus was evident in any of the fetal or maternal fluids.     

Ultrasonographic evaluation of the equine placenta by transrectal and transabdominal approach in the normal pregnant mare

The objective of this study was to determine normal variations in the utero placental thickness during mid- and late gestation in the mare. Normal, healthy pregnant mares (n = 9) were examined monthly from 4 mo of gestation until parturition by transrectal and transabdominal ultrasonography. At each examination, the combined thickness of the uterus and the placenta (CTUP) was measured at the placento-cervical junction (transrectally) and at the uterine body or the uterine horns (transabdominally). In addition, the echogenicity of the amniotic and allantoic fluids was evaluated by transrectal ultrasonography. Following parturition and expulsion of the fetal membranes, the allantochorion was measured and visually examined for abnormalities. At all examinations, both transrectal and transabdominal, the chorioallantois and the uterus were indistinguishable from each other on the ultrasound image. The CTUP, measured by transrectal ultrasonography did not change between 4 and 8 mo of gestation, but increased significantly for each month between 10 and 12 mo of gestation (P < 0.001). A change in the CTUP was detected between months when measured by transabdominal ultrasonography, but no distinct pattern in these changes was observed. No correlation was found between transabdominal and transrectal measurements of the CTUP. The echogenicity of the amniotic and allantoic fluids did not consistently change over time during mid- and late gestation. The amniotic fluid was more echogenic than the allantoic fluid at most examinations from 6 mo of pregnancy and throughout gestation (P < 0.05). It was concluded that transrectal ultrasonographic examination to assess the CTUP and the echogenicity of the fetal fluids is superior to the transabdominal approach. We suggest that transrectal ultrasonographic examination should be added to current diagnostic tools during late gestation and that it be part of the biophysical profile of high risk equine pregnancies.     

Perturbations in the biochemical composition of fetal fluids are apparent in surviving bovine somatic cell nuclear transfer pregnancies in the first half of gestation

Amniotic and allantoic fluid volumes and composition change dynamically throughout gestation. Cattle that are pregnant with somatic cell nuclear transfer (NT) fetuses show a high incidence of abnormal fluid accumulation (particularly hydrallantois) and fetal mortality from approximately midgestation. To investigate fetal fluid homeostasis in these pregnancies, Na, K, Cl, urea, creatinine, Ca, Mg, total PO(4), glucose, fructose, lactate, total protein, and osmolalities were measured in amniotic and allantoic fluids collected at Days 50, 100, and 150 of gestation from NT pregnancies and those generated by the transfer of in vitro-produced embryos or by artificial insemination. Deviations in fetal fluid composition between NT and control pregnancies were apparent after placental and fetal organ development, even when no gross morphological abnormalities were observed. Individual NT fetuses were affected to varying degrees. Elevated allantoic Na was associated with lower K and increased allantoic fluid volume or edema of the fetal membranes. Total PO(4) levels in NT allantoic and amniotic fluid were elevated at Days 100 and 150. This was not accompanied by hypophosphatemia at Day 150, suggesting that PO(4) acquisition by NT fetuses was adequate but that its readsorption by the kidneys may be impaired. Excessive NT placental weight was associated with low allantoic glucose and fructose as well as high lactate levels. However, the fructogenic ability of the NT placenta appeared to be normal. The osmolality of the fetal fluids was maintained within a narrow range, suggesting that the regulation of fluid composition, but not osmolality, was impaired in NT pregnancies.     

Concentrations of altrenogest in plasma of mares and foals and in allantoic and amniotic fluid at parturition

Treatment with the progestin altrenogest is widely used in pregnant mares. The fact that foals born from healthy mares treated with altrenogest until term suffered from neonatal problems raises the question of direct effects of altrenogest on vital functions in the neonate. We have therefore investigated altrenogest concentrations in maternal and neonatal blood plasma and in fetal fluids. Pregnant mares were treated with altrenogest orally once daily (0,088 mg/kg bodyweight, n = 7) or left untreated (n = 8) from 280 d of gestation until foaling. Altrenogest concentration was determined in plasma of the mares, their foals and in amniotic and allantoic fluid. The concentration of altrenogest in plasma from treated mares (2.6 ± 1.0 ng/mL) was significantly lower than in plasma from their foals immediately after birth (5.6 ± 1.9 ng/mL; p < 0.05), but was significantly higher than in their fetal fluids (amniotic fluid: 0.4 ± 0.1 ng/mL; p < 0.05; allantoic fluid: 3.0 ± 1.5 ng/mL). Altrenogest was undetectable in maternal and fetal plasma and fetal fluids of control pregnancies at all times. Altrenogest concentration in plasma of foals from treated mares was strongly correlated to the altrenogest concentration in plasma of their dams (r = 0.938, p < 0.001) and in amniotic (r = 0.886, p < 0.001) and allantoic fluid (r = 0.562, p < 0.05). A significant decrease in altrenogest concentration between the time periods 0-15 min, 30-120 min, and 180-360 min after parturition was seen in the plasma from foals born to altrenogest-treated mares. In conclusion, our data demonstrate that altrenogest reaches the equine fetus at high concentrations.     

Urethral and urachal urine output to the amniotic and allantoic sacs in fetal sheep

A chronic fetal sheep preparation was developed to measure, without interruption in utero, urethral and urachal urine output to the amniotic and allantoic sacs, respectively. Fetal urethral, urachal and total urine output was measured during a 5 day post-operative period, in late gestation. Total fetal urine output increased from day 1 to a volume of 1216 +/- 115 ml/day (SEM) on day 5 post-operative. Urachal urine output increased significantly from 12 ml/day on day 1 to 467 ml/day on day 5 (P less than 0.05). Fetal arterial blood gases, pH and immunoreactive ACTH, cortisol and immunoreactive arginine vasopressin concentrations were stable throughout the 5-day recovery period. Fetal urachal urine output to the allantoic cavity and total fetal urine output appears to require 4-5 days to stabilize post-operatively. Fetal urine is a major source of amniotic and allantoic fluid in late gestation and the volume of these sacs may be influenced, in part, by the distribution of urethral and urachal urine output.     

Development and efficacy of ultrasound-guided fetal fluid aspiration techniques for prenatal diagnosis of caprine beta-mannosidosis

Ultrasound-guided fetal fluid sampling was performed on 13 pregnant goats at Days 59 to 65 of gestation to establish safe techniques for accurate sampling and to determine the feasibility of prenatal diagnosis of beta-mannosidosis. Fluids were analyzed for electrolyte and creatinine content to assess accuracy of sampling. Values correlated well with previously reported concentrations for caprine and ovine fetal fluids at the same gestational stage. The single abortion which occurred following ultrasound-guided sampling was correlated with placentome penetration and aspiration of bloody fluids. Thin layer chromatography of amniotic and allantoic fluids was performed to detect oligosaccharides that accumulate in beta-mannosidosis. Abnormal accumulated oligosaccharides were identified in the allantoic but not amniotic fluid from a beta-mannosidase-deficient 62-d-old fetus. Thus, allantocentesis was shown to be an optimal, safe procedure for providing information at this gestational stage to diagnose caprine beta-mannosidosis.     

Proteins in the amniotic and allantoic fluids of fetal pigs

Seven proteins were identified in the amniotic and allantoic fluids of fetal pigs (Sus scrofa domesticus) using crossed immunoelectrophoresis: albumin, fetuin, transferrin, alpha-fetoprotein (AFP), alpha 1-acid glycoprotein, alpha 1-antitrypsin and alpha 2-macroglobulin. The total protein concentrations were determined by the method of Bradford and individual protein concentrations by radial immunodiffusion or rocket immunoelectrophoresis. Transferrin and fetuin were the major proteins in amniotic fluid during the second trimester of gestation and together with AFP and albumin accounted for the majority of the total protein in amniotic, but not allantoic fluid.     

IGF-I and NEFA concentrations in fetal fluids of term pregnancy dogs

Insulin-like growth factor-I (IGF-I) and non-esterified fatty acids (NEFA) play an essential role in fetal growth and development. To date, fetal fluids IGF-I and NEFA levels at term canine pregnancy are unknown and could be related to the neonatal development and breed size. For these reasons, the aims of the present study were as follows: (1) to evaluate IGF-I and NEFA concentrations in fetal fluids collected from normally developed and viable newborn puppies born at term of normal pregnancies; (2) to assess possible differences between IGF-I and NEFA levels in amniotic compared with allantoic fluid; (3) to detect possible relationship between breed body size and IGF-I and NEFA amniotic and allantoic concentrations; (4) to evaluate possible differences in IGF-I fetal fluids levels between male and female puppies; and (5) to assess possible correlations between the two hormones in each type of fluid. The study enrolled 25 pure breed bitches submitted to elective Cesarean section at term because of the high risk of dystocia or previous troubles at parturition. At surgery, amniotic and allantoic fluids were collected and assayed for IGF-I and NEFA. IGF-I and NEFA amounts in both amniotic and allantoic fluids of different breed size bitches (small: ≤10 kg; medium: 11–25 kg; large: 26–40 kg) were detected, as well as the effect of gender on IGF-I levels. On a total of 73 amniotic and 76 allantoic samples collected by normal, viable, and mature newborns, the mean IGF-I concentration was significantly higher in amniotic than in allantoic fluid in all three groups, but the amniotic IGF-I levels were significantly lower in small and medium size bitches when compared with large ones. No significant differences were found in allantoic IGF-I concentrations among size groups. A significant effect of the puppy gender on IGF-I content in both fetal fluids was not reported. Regarding NEFA, in all the three groups, the mean NEFA concentration did not significantly differ between amnion and allantois, but in both fetal fluids, higher NEFA levels were detected in samples belonging to small breeds when compared with medium and large. These data strongly indicated that, also in the dog, a relation between fetal fluids IGF-I and NEFA concentrations and breed size exists. Further research is needed to elucidate the possible role of IGF-I and NEFA in the pathologic conditions related to canine fetal growth.     

Hormonal and physical changes associated with bovine conceptus development.

Conceptus (placental membranes, fetal fluids and fetus) development was characterized between Days 27 and 111 of gestation. Progestagens, oestrone, oestradiol, oestrone sulphate and prostaglandins (PG) F were measured in maternal plasma and allantoic and amniotic fluids. Protein concentrations are described for fetal fluids. The early increase in placental membrane weight from 1.12 g (27 days) to 58.45 g (50 days) was associated with oestrogen production presumably of conceptus origin. Oestrogens increased significantly in allantoic and amniotic fluids throughout the period studied with oestrone being the primary free oestrogen, rising from 2 pg/ml (Day 33) to 144 ng/ml by 111 days in allantoic fluid. Changes in plasma oestrogens of the maternal circulation were not detected until after Day 70 at which time oestrone concentration was greater than that of oestradiol. Fetal fluid concentrations of progestagens, oestrone sulphate and PGF were not related to maternal plasma levels and a sequestration of these hormones by the allantois is postulated.     

Origin and developmental patterns of lactase and other glycosidases in sheep amniotic and allantoic fluid.

Intestinal lactase activity (with its associated cellobiase, 4-methylumbelliferyl-beta-galactosidase and -beta-glucosidase activities) was used as a specific intestinal marker enzyme to study the release of protein and enzymes of intestinal origin in sheep amniotic fluid during gestation. In amniotic fluid, intestinal lactase activity peaked at 66--85 days of gestation and then decreased with gestation. This enzyme activity was very low or absent in allantoic fluid throughout gestation suggesting that there is no important transfer of amniotic fluid lactase towards the allantoic cavity. Maltase and 4-methylumbelliferyl-alpha-glucosidase showed no statistically significant variation with gestation in both amniotic and allantoic fluid whereas alpha-galactosidase and N-acetyl-beta-hexosaminidase which were first higher in allantoic than in amniotic fluid increased in amniotic fluid to reach allantoic fluid levels near term. Such patterns are consistent with the suggestion that the fetal urine is a source of alpha-galactosidase and N-acety-beta-hexosaminidase activities and that sheep urine is first accumulated in the allantoic sac via the urachus up to 86--90 days of gestation and thereafter passes more and more into the amniotic sac.     

Polyamine synthesis from proline in the developing porcine placenta

Polyamines (putrescine, spermidine, and spermine) are essential for placental growth and angiogenesis. However, little is known about polyamine synthesis in the porcine placenta during conceptus development. The present study was conducted to test the hypothesis that arginine and proline are the major sources of ornithine for placental polyamine production in pigs. Placentae, amniotic fluid, and allantoic fluid were obtained from gilts on Days 20, 30, 35, 40, 45, 50, 60, 90, and 110 of the 114-day gestation (n = 6 per day). Placentae as well as amniotic and allantoic fluids were analyzed for arginase, proline oxidase, ornithine aminotransferase (OAT), ornithine decarboxylase (ODC), proline transport, concentrations of amino acids and polyamines, and polyamine synthesis using established radiochemical and chromatographic methods. Neither arginase activity nor conversion of arginine into polyamines was detected in the porcine placenta. In contrast, both proline and ornithine were converted into putrescine, spermidine, and spermine in placental tissue throughout pregnancy. The activities of proline oxidase, OAT, and ODC as well as proline transport, polyamine synthesis from proline, and polyamine concentrations increased markedly between Days 20 and 40 of gestation, declined between Days 40 and 90 of gestation, and remained at the reduced level through Day 110 of gestation. Proline oxidase and OAT, but not arginase, were present in allantoic and amniotic fluids for the production of ornithine (the immediate substrate for polyamine synthesis). The activities of these two enzymes as well as the concentrations of ornithine and total polyamines in fetal fluids were highest at Day 40 but lowest at Days 20, 90, and 110 of gestation. These results indicate that proline is the major amino acid for polyamine synthesis in the porcine placenta and that the activity of this synthetic pathway is maximal during early pregnancy, when placental growth is most rapid. Our novel findings provide a new base of information for future studies to define the role of proline in fetoplacental growth and development.     

The influence of gestational age and onset of labour on determinants of fetal-maternal fluid and electrolyte balance in sheep.

Our aim was to compare the effects of gestational age and the timing of the onset of labour on factors influencing fetal fluid and electrolyte balance and urine production in fetal sheep. We measured the volume and composition of fetal urine and amniotic and allantoic fluids, as well as fetal and maternal plasma composition and micturition episodes in sheep during late gestation until the onset of labour. We found that daily fetal urine production and urethral urine flow per micturition episode increased significantly in relation to the onset of labour but not to gestational age (P < 0.05). In the 2 days preceding the onset of labour fetal urine and amniotic fluid K+ concentrations and urine osmolality increased significantly and the Na+/K+ ratio in allantoic fluid decreased significantly (P < 0.05). There was also a significant fall in fetal arterial SaO2 (P < 0.05) but no significant changes occurred in fetal plasma electrolyte composition, osmolality or AVP concentrations. Fetal plasma cortisol and prolactin concentrations and amniotic and allantoic fluid prolactin concentrations increased significantly and progressively in association with both advancing gestation and the onset of labour whereas maternal plasma prolactin concentrations increased significantly only in the 2 days before the onset of labour (P < 0.05). We conclude that some developmental aspects of fetal fluid and electrolyte balance, including renal function, are more closely related to the timing of parturition than to gestational age per se.     

Arginine nutrition and fetal brown adipose tissue development in diet-induced obese sheep

The global incidence of human obesity has more than doubled over the past three decades. An ovine model of obesity was developed to determine effects of maternal obesity and arginine supplementation on maternal, placental, and fetal parameters of growth, health, and well being. One-hundred-twenty days prior to embryo transfer, ewes were fed either ad libitum (n?=?10) to induce obesity or 100% National Research Council-recommended nutrient requirements (n?=?10) as controls. Embryos from superovulated ewes with normal body condition were transferred to the uterus of control-fed and obese ewes on day 5.5 post-estrus to generate genetically similar singleton pregnancies. Beginning on day 100 of gestation, obese ewes received intravenous administration of saline or L-arginine-HCl three times daily (81?mg arginine/kg?body?weight/day) to day 125, whereas control-fed ewes received saline. Fetal growth was assessed at necropsy on day 125. Maternal obesity increased (1) percentages of maternal and fetal carcass lipids and (2) concentrations of leptin, insulin, glucose, glutamate, leucine, lysine and threonine in maternal plasma while reducing (1) concentrations of progesterone, glycine and serine in maternal plasma and (2) amniotic and allantoic fluid volumes. Administration of L-arginine to obese ewes increased arginine and ornithine concentrations in maternal and fetal plasma, amniotic fluid volume, protein content in maternal carcass, and fetal brown adipose tissue (+60%), while reducing maternal lipid content and circulating leptin levels. Fetal or placental weight did not differ among treatments. Results indicate that arginine treatment beneficially reduces maternal adiposity and enhances fetal brown adipose tissue development in obese ewes.     

The role of fetal urinary excretion in the transfer of ethanol into amniotic fluid after maternal administration of ethanol to the near-term pregnant ewe

The objective of this study was to determine whether fetal urinary excretion is a major route of ethanol transfer into the amniotic fluid surrounding the fetus following maternal administration of ethanol. Conscious instrumented pregnant ewes between 130 and 137 days' gestation (term, 147 days) with (n = 3) or without (n = 3) a catheter in the fetal bladder were administered 1 g ethanol/kg maternal body weight as a 1-h maternal intravenous infusion. Maternal blood, fetal blood, and amniotic fluid samples were collected at selected times, and fetal urine was collected continuously from the bladder-cannulated fetus during the 14-h study for the determination of ethanol concentrations. Fetal urinary excretion of ethanol occurred, and the total amount of ethanol excreted represented 0.30 +/- 0.07 (SD)% of the maternal ethanol dose. The renal clearance of ethanol by the fetus was 0.43 +/- 0.06 mL/min. The pharmacokinetics of ethanol in the maternal-fetal unit and the amniotic fluid for the bladder-cannulated fetal preparation were similar to the data for the nonbladder-cannulated preparation. The data indicate that fetal urinary excretion of ethanol is a secondary route of ethanol transfer into the amniotic fluid. It would appear that diffusion of ethanol across membranes from the maternal and fetal circulations is a major route of ethanol transfer into this intrauterine compartment.     

Distribution of alpha 1-fetoprotein in fetal plasma, allantoic fluid, amniotic fluid and maternal plasma of cows.

Maximal concentrations of AFP, measured by RIA, were obtained in fetal plasma and amniotic and allantoic fluid between the 3rd and 4th month of gestation, with levels declining thereafter until term. AFP values in maternal plasma were unchanged. Throughout gestation, AFP values were higher in allantoic than in amniotic fluid and the ratio of allantoic fluid/amniotic fluid AFP was significantly correlated with gestational age.     

Pregnancy-specific protein B (PSPB), progesterone and some biochemical attributes concentrations in the fetal fluids and serum and its relationship with fetal and placental characteristics of Iraqi riverine buffalo (Bubalus bubalis)

This study was carried out to demonstrate the pregnancy-specific protein B (PSPB), progesterone and some biochemical parameters concentrations in amniotic fluid, allantoic fluid and fetal serum collected from slaughtered Iraqi riverine pregnant buffaloes at three different months of gestation (6th, 7th and 8th). Ten out of 22 adult buffaloes of 4.6 ± 0.97 years old were used in this study. The buffaloes were mated naturally by monitoring the estrus cycles via appearance of vaginal fluids and mounting by bulls. Pregnancy was checked for these buffaloes by non-returning to estrus for three estrus cycles and assured by rectal palpation on day 61 post-mating (PM). Buffaloes were slaughtered at three different periods of gestation (three at 6th month, four at 7th month and three at 8th month of gestation) to verify the progesterone and PSPB as well as some blood attributes levels (glucose, cholesterol, total protein, albumin, globulins and albumin: globulins ratio) in amniotic fluid (AF), allantoic fluid (LF) and fetal serum (FS). Progesterone was higher (P<0.01) in LF at the 8th month of gestation and lower in FS during the 7th and 8th months of pregnancy. PSPB concentrations were greater in FS (6th and 8th months in particular) than in both AF and LF. The overall mean of cholesterol concentration was higher in FS (P<0.05) followed by AF and LF that had the lowest concentration. The FS exhibited higher total protein during the three gestation periods. Most of fetal and placental measurements increased as the pregnancy advanced. In conclusion, these results described, for the first time, the PSPB and progesterone concentrations and blood characteristics in fetal fluids and serum in water riverine buffaloes during different stages of pregnancy. Progesterone concentrations were greater in allantoic fluid than in other fluids. In contrast, PSPB and other blood attributes were higher in fetal serum than other fluids of Iraqi riverine buffaloes. These findings reflect the changes in hormones, proteins and other metabolites during different gestation periods.