Vitellogenin, lipid and carbohydrate metabolism during vitellogenesis and pregnancy, and after hormonal induction in the blenny Zoarces viviparus (L.).

1. Ovarian vitellogenic growth in Zoarces viviparus lasts about 2 months. Vitellogenesis is immediately followed by ovulation, fertilization and a pregnancy period of 4 months. Vitellogenin is observed in the blood during vitellogenesis, but declines during the first month of pregnancy. 2. The largest amount of liver lipid is found before vitellogenesis is initiated. During pregnancy the liver is depleted of lipid and glycogen, and total lipid and phospholipid is accumulating in the blood. 3. Estradiol treatment during pregnancy results in a dose-dependent increase in vitellogenin and lipids of the blood. 4. In late pregnancy, birth can be provoked with progesterone alone, or with combined progesterone and estradiol treatment.     

Size at birth,maternal nutritional status in pregnancy,and blood pressure at age 17: population based analysis.

OBJECTIVE: To assess the effect of size at birth, maternal nutrition, and body mass index on blood pressure in late adolescence. DESIGN: Population based analysis of birth weight corrected for gestational age, mother''s weight before pregnancy and weight gain in pregnancy, obtained from the Jerusalem perinatal study, and blood pressure and body mass index at age 17, available from military draft records. SETTING: Jerusalem, Israel. SUBJECTS: 10,883 subjects (6684 men and 4199 women) born in Jerusalem during 1974-6 and subsequently drafted to the army. MAIN OUTCOME MEASURES: Systolic and diastolic blood pressures measured at age 17 and their correlation with birth weight, size at birth, mother''s body mass index and weight gain during pregnancy, and height and weight at age 17. RESULTS: Systolic and diastolic blood pressures were significantly and positively correlated with body weight, height, body mass index at age 17, and with mother''s body weight and body mass index before pregnancy, but not with birth weight or mother''s weight gain in pregnancy. CONCLUSION: Variables reflecting poor intrauterine nutrition, including low maternal body mass index before pregnancy, poor maternal weight gain in pregnancy, and being born small for gestational age, were not associated with a higher blood pressure in late adolescence.     

Influence of progesterone on arterial blood and CSF acid-base balance in women

To study the mechanism of the action of progesterone on pulmonary ventilation during pregnancy, arterial and cerebrospinal fluid (CSF) acid-base parameters were measured in 59 pregnant and 36 nonpregnant women at the periods of follicular phase, luteal phase, early pregnancy, late pregnancy, and puerperium. Marked respiratory alkalosis in both arterial blood and CSF was observed in pregnancy and puerperium. The degree of hypocapnia observed in the luteal phase and during pregnancy was closely related to the progesterone level in arterial blood. In conclusion, it is unlikely that the observed hyperventilation results from stimulation at the central chemosensitive areas or peripheral chemoreceptors.     

Progesterone is not responsible for the blood pressure fall in late-pregnant New Zealand genetically hypertensive rats

In various models of experimental and genetic hypertension in rats, blood pressure is markedly reduced during late pregnancy. The period during which the blood pressure reduction occurs is also the period when plasma progesterone is maximally elevated, and administration of progesterone to renal hypertensive rats has been reported to reduce blood pressure (J. Armstrong, 1959, Proc. Soc. Exp. Biol. Med. 102:452-455). To test the possibility that elevated plasma progesterone is responsible for the blood pressure reduction in late pregnancy, on Day 14 of pregnancy a group of New Zealand genetically hypertensive (NZGH) rats was ovariectomized and implanted with progesterone-filled capsules, to maintain plasma progesterone at low levels just sufficient to maintain pregnancy, and compared with intact, pregnant NZGH. Ovariectomy did not alter the characteristic course of blood pressure reduction seen in late-pregnant intact NZGH rats. In addition, daily administration of progesterone (15 mg/kg, sc) for 14 days did not alter blood pressure of either nonpregnant NZGH rats or New Zealand normotensive rats with chronic 1-kidney, 1-clip hypertension. It is concluded that blood pressure of NZGH rats is reduced to near normotensive levels in late pregnancy, as reported for other models of rat hypertension, but that elevated plasma progesterone levels are not requisite for that reduction and do not reduce blood pressure of renal hypertensive rats.     

Lung mechanics and blood gases in pregnant guinea pigs

Lung resistance and compliance were measured in early pregnant, late pregnant and non pregnant guinea pigs. Lung resistance was increased, lung compliance was decreased in pregnancy. A new finding was the increase of chest wall compliance in the course of pregnancy. In order to obtain a sufficient gas exchange during artificial ventilation, pregnant animals have to be ventilated with a higher frequency or a higher pressure than non pregnant controls.     

Antioxidant status of ewe's blood during pregnancy and lactation

Antioxidant status of ewe's blood during pregnancy and lactation was studied. It is revealed that the lipid peroxidation in erythrocytes is decreased, whereas in blood plasma is increased in the middle pregnancy, reaching the maximum shortly before peak of progesterone production. The activities of antioxidant enzymes are increased at the end of pregnancy, when the level of progesterone in blood is maximal. The positive correlation between plasma progesterone level and activity of erythrocyte superoxide dismutase (p < 0.01), between plasma cortisol concentration and total antioxidant capacity of blood plasma (p < 0.05) are revealed. It is shown, that the activities of antioxidant enzymes reach a maximum in the critical periods of pregnancy, providing the protection of the maternal organism and the fetus against negative influence of free radicals. The positive correlation between a level of hormones and separate parameters of antioxidant system in blood allows to assume, that progesterone participates in the regulation of enzymatic part of the antioxidant system, while cortisol is implicated in the regulation of the non-enzymatic component of this system in ewes.     

The Effects of Pregnancy and Feeding on the Insulin and Glucose Concentrations in Blood of Ewes in Late Pregnancy

In 8 experimental ewes on normal diet the influence of pregnancy and feeding on insulin and glucose in the blood was studied. A reduction in insulin concentration was found as pregnancy advanced. Blood glucose fluctuated, but during late pregnancy the blood glucose level was significantly lower in twin–pregnant ewes than in ewes pregnant with 1 fetus. No increase in insulin concentration was demonstrated in twin–pregnant ewes after feeding, on the contrary an increase was found in ewes pregnant with 1 fetus. A limited effect of feeding on the glucose concentration was observed, especially compared to the reference range. A positive correlation was obtained between the concentration of glucose and insulin in the blood.     

Urine collection in the common marmoset (Callithrix jacchus) and its applicability to endocrinological studies

We investigated a new method of urine collection in the common marmoset. We entered the cage as soon as the light cycle started in the breeding room and collected urine from the animal directly without any restraint. We were able to take separate samples from completely different individuals housed together for behavioral studies in the same cage. Urine and blood samples were taken from individuals from late pregnancy through postpartum nursing period. Cortisol and prolactin concentrations measured in urine were compared to those measured in blood to evaluate this collection method. LH/CG level in the urine samples was also measured. Urine data in females indicated a tendency toward high cortisol values during late pregnancy, a sharp drop before parturition, and increase after delivery. In females cortisol levels measured in blood closely resembled concentrations measured in urine. Urine cortisol in males clearly indicated an increase postpartum, but the increase was not indicated in plasma. Plasma and urine prolactin concentrations in females made a similar increase during lactation. Male's plasma prolactin clearly indicated an increase directly proportional to strong behavioral contact with the infant. We also confirmed hormonal changes during pregnancy, and postpartum ovulation and subsequent pregnancies, from urine LH/CG data. We found this method extremely useful because of the high correlation between cortisol, prolactin and LH/CG data from blood and urine. Additionally, we collected urine samples with little stress to the animal from fear, irritation, pain, etc.     

Free IGF-I, IGFBP-1, and the binary complex of IGFBP-1 and IGF-I are increased during human pregnancy

BACKGROUND/AIMS: To investigate changes in free insulin-like growth factor I (IGF-I) and IGF-binding protein 1 (IGFBP-1) complexed IGF-I during human pregnancy. METHODS: Overnight fasting serum was obtained in a longitudinal design from 11 women with non-complicated pregnancy at gestation weeks 6-10, 16-20, 24-28 and 35-38 and, for comparison, 5 weeks post-partum. All samples were analyzed for total and free IGF-I and IGF-II, IGFBP-3 and IGFBP-3 proteolysis, total and non-phosphorylated (np-) IGFBP-1, and IGFBP-1 complexed IGF-I. RESULTS: Total IGF-I was increased in late pregnancy (week 35-38) (p < 0.001), whereas free IGF-I was significantly increased by 77% already at week 6-10 (p = 0.004) and by 140% (p = 0.002) at week 34-38, when compared to post-partum levels. At weeks 16-20 and 24-28, levels of free IGF-I were not significantly different from post-partum levels. Significant IGFBP-3 proteolysis was detectable from week 6-10 and throughout pregnancy (p < 0.05). Total and np-IGFBP-1 were significantly increased from 16-20 weeks of pregnancy (both p < 0.05) and IGFBP-1 complexed IGF-I was increased 2-fold from week 16-20 and throughout pregnancy (p < 0.05). However, the saturation of IGFBP-1 remained constant at 27-29% during the study. CONCLUSION: We found evidence of increased free IGF-I and increased IGF-I in binary complexes during pregnancy, possibly caused by IGFBP-3 proteolysis and decreased ternary complex formation.     

The effect of maternal diet during late pregnancy on postnatal changes in blood and liver metabolites and hepatic hydroxymethylglutaryl-CoA synthase activity in the offspring

Both starvation of and feeding a high linoleic acid content diet to rats during late pregnancy resulted in marked differences in the metabolism of the fed offspring immediately after birth when compared to control neonates (mother fed the normal high carbohydrate content laboratory diet during pregnancy). In particular differences in postnatal changes in blood glucose, non esterified fatty acids and ketone bodies and in hepatic triglyceride content were observed. Many of the differences appeared to be related to the variations in blood and hepatic metabolites present at birth in the various groups of animals. A similar situation also existed with respect to postnatal changes in the activity of hydroxymethylglutaryl-CoA synthase.     

Blood Copper, Zinc, Calcium, and Magnesium Levels During Different Duration of Pregnancy in Chinese

Concentrations of various trace elements are altered during pregnancy with changes in the mother’s physiology and the requirements of growing fetus. The aim of the present longitudinal study was to learn the changes of trace element copper (Cu), zinc (Zn), calcium (Ca), and magnesium (Mg) of normal pregnant woman during different durations of pregnancy and establish the reference values of changes of statistical significance. Blood samples were obtained from 128 normal pregnant women during early (10–14th week), mid (20–24th week), and late (30–34th week) pregnancy and 6–12th week postpartum and 120 healthy unpregnant healthy women. The full blood concentrations of chosen elements were measured by means of an atomic absorption spectrophotometer. Changes on levels of Cu, Ca, and Mg during all the three durations of pregnancy and Zn during mid and late pregnancy and postpartum were of statistical significance and new reference values of them were set in the present study. These new reference values will be helpful in assessing the health status of pregnant women with a socioeconomic and racial background similar to those of our study participants and give treatments to them promptly.     

Properties of chromatin of peripheral blood lymphocytes in women with threatened abortion

The authors studied the properties of peripheral blood lymphocyte chromatin from donors (non-pregnant women), from women with normal pregnancy and during threatened abortion. Using three independent cytochemical methods that characterize the DNA accessibility for acridine orange and 3H-actinomycin D and the presence in histones of free amino groups, it has been established that lymphocyte chromatin from women during threatened abortion is repressed to a greater degree than in those with normal pregnancy. The data presented demonstrate the prospectiveness of the use of the cytochemical tests for chromatin properties with a purpose of diagnosing whether the pregnancy will be full-term and treatment control.     

Glucose homeostasis during canine pregnancy: Insulin resistance,ketosis, and hypoglycemia

Through a variety of mechanisms, pregnancy causes insulin resistance, which suppresses the intracellular transport of glucose and increases blood glucose concentrations. In the extreme, gestational diabetes (GDM) mellitus may develop. In addition to insulin resistance, pregnant bitches have decreased ability to produce glucose via gluconeogenesis, glycogenolysis and lipolysis, because the normal multi-factorial responses to hypoglycemia are blunted late in pregnancy. Simply fasting late-pregnant bitches is sufficient to cause blood glucose and insulin concentrations to decrease and ketones to increase. The purpose of this paper is to review the clinical implications of pregnancy-associated changes in glucose homeostasis in bitches.     

Glucose homeostasis during canine pregnancy: Insulin resistance, ketosis, and hypoglycemia

Through a variety of mechanisms, pregnancy causes insulin resistance, which suppresses the intracellular transport of glucose and increases blood glucose concentrations. In the extreme, gestational diabetes (GDM) mellitus may develop. In addition to insulin resistance, pregnant bitches have decreased ability to produce glucose via gluconeogenesis, glycogenolysis and lipolysis, because the normal multi-factorial responses to hypoglycemia are blunted late in pregnancy. Simply fasting late-pregnant bitches is sufficient to cause blood glucose and insulin concentrations to decrease and ketones to increase. The purpose of this paper is to review the clinical implications of pregnancy-associated changes in glucose homeostasis in bitches.     

Uterine blood flow of cows during the oestrous cycle and early pregnancy: effect of the conceptus on the uterine blood supply.

Blood flow to each uterine horn of cows during the oestrous cycle and early pregnancy was determined daily by use of electromagnetic blood flow probes placed around both middle uterine arteries. The pattern of blood flow to uteri of pregnant and non-pregnant cows was similar until Day 14 after mating or oestrus. Between Days 14 and 18 of pregnancy blood flow to the uterine horn containing the conceptus increased (P less than 0.01) 2- to 3-fold, whereas blood flow to the non-gravid uterine horn in these cows remained constant. No corresponding increase in blood flow to the uterine horn ipsilateral to the ovary bearing the CL was observed in non-pregnant cows during this 4-day period. By Day 19 of pregnancy, blood flow to the gravid uterine horn had returned to a level similar to that observed on Day 13. Blood flow to both uterine horns of pregnant cows remained constant from Days 19 to 25 and then increased to the gravid horn (P less than 0.01) markedly until Day 30 whereas blood flow to the non-gravid horn remained low. Uterine blood flow during the oestrous cycle of non-pregnant cows was positively correlated (P less than 0.01) with systemic concentrations of oestradiol and the ratio of oestradiol (pg/ml) to progesterone (ng/ml). There was no association between oestradiol concentrations and blood flow to the gravid uterine horn. These data indicate local control of uterine blood flow by the bovine conceptus which may function to create optimal conditions for the continuation of pregnancy.     

Dynamics of antibody nuclease activity in blood of women during pregnancy and lactation

In human milk we previously found catalytic antibodies (abzymes) catalyzing hydrolysis of DNA, RNA, NMP, NDP, and NTP and also phosphorylation of proteins and lipids. In the present study we have analyzed nuclease activities of antibodies in blood of women during pregnancy and lactation. Blood of healthy male and female volunteers lacked catalytically active antibodies, whereas antibodies from blood of pregnant women hydrolyzed DNA and RNA and their relative activity varied over a wide range. Relative blood abzyme activities significantly increased after delivery and at the beginning of lactation. The highest abzyme activity was observed in blood of parturient women. Although the dynamics of changes in antibody DNase activity during pregnancy was rather individual for each woman, there was a common trend in the increase in antibody activity in the first and/or third trimester of the pregnancy. The DNase activity of IgG and IgM from blood of healthy pregnant women was 4-5 times less than that from pregnant women with pronounced autoimmune thyroiditis.     

Quantitative,high-resolution epigenetic profiling of CpG loci identifies associations with cord blood plasma homocysteine and birth weight in humans

Supplementation with folic acid during pregnancy is known to reduce the risk of neural tube defects and low birth weight. It is thought that folate and other one-carbon intermediates might secure these clinical effects via DNA methylation. We examined the effects of folate on the human methylome using quantitative interrogation of 27,578 CpG loci associated with 14,496 genes at single-nucleotide resolution across 12 fetal cord blood samples. Consistent with previous studies, the majority of CpG dinucleotides located within CpG islands exhibited hypomethylation while those outside CpG islands showed mid-high methylation. However, for the first time in human samples, unbiased analysis of methylation across samples revealed a significant correlation of methylation patterns with plasma homocysteine, LINE-1 methylation and birth weight centile. Additionally, CpG methylation significantly correlated with either birth weight or LINE-1 methylation were predominantly located in CpG islands. These data indicate that levels of folate-associated intermediates in cord blood reflect their influence and consequences for the fetal epigenome and potentially on pregnancy outcome. In these cases, their influence might be exerted during late gestation or reflect those present during the peri-conceptual period.Key words: cord blood, birth weight, folic acid, homocysteine, BeadArray, hierarchical clustering, Illumina     

Quantitative,high-resolution epigenetic profiling of CpG loci identifies associations with cord blood plasma homocysteine and birth weight in humans

Supplementation with folic acid during pregnancy is known to reduce the risk of neural tube defects and low birth weight. It is thought that folate and other one-carbon intermediates might secure these clinical effects via DNA methylation. We examined the effects of folate on the human methylome using quantitative interrogation of 27,578 CpG loci associated with 14,496 genes at single-nucleotide resolution across 12 fetal cord blood samples. Consistent with previous studies, the majority of CpG dinucleotides located within CpG islands exhibited hypo-methylation while those outside CpG islands showed mid-high methylation. However, for the first time in human samples, unbiased analysis of methylation across samples revealed a significant correlation of methylation patterns with plasma homocysteine, LINE-1 methylation and birth weight centile. Additionally, CpG methylation significantly correlated with either birth weight or LINE-1 methylation were predominantly located in CpG islands. These data indicate that levels of folate-associated intermediates in cord blood reflect their influence and consequences for the fetal epigenome and potentially on pregnancy outcome. In these cases, their influence might be exerted during late gestation or reflect those present during the peri-conceptual period.     

Maternal thyroid function in early and late pregnancy.

Thyroid function was investigated during and after pregnancy in 12 healthy euthyroid women. During pregnancy, serum total T4 (TT4) levels were significantly elevated and nearly stable, while thyroxine-binding globulin (TBG) levels progressively increased till the 7th month. A slight elevation, though not significant, of free T4 (fT4) was recorded in early pregnancy. In the following months, fT4, free T3 (fT3) and the T4/TBG ratio progressively diminished, reaching a plateau at the 7th month. Serum TSH levels, measured by an ultrasensitive immunofluorometric assay, were comparable to postpartum values during the first trimester and showed a moderate upward trend with the progression of pregnancy. The evaluation of 24-hour TSH profiles was performed in 5 women during the first trimester of pregnancy. In all women, the circadian rhythm of TSH was present with a normal nocturnal surge, though anticipated in 1 case. In summary (1) during the first trimester of pregnancy, the increased thyroid activity does not seem to be only sustained by pituitary TSH which remains unmodified; the negative correlation between TSH and hCG levels might suggest that hCG also stimulates the gland to increase thyroid hormone output, and the presence of a normal TSH circadian rhythm indicates that the central mechanism of neuroregulation of the pituitary-thyroid axis is preserved in early pregnancy, and (2) in late pregnancy, a marked decrease in free thyroid hormone fractions is accompanied by serum TSH levels still in the normal range, indicating a modification of thyroid homeostasis which might recognize various etiological factors.