A quantitative study of rat uterine sympathetic innervation during pregnancy and post partum

2006 ◽  
Vol 18 (5) ◽  
pp. 525 ◽  
Author(s):  
R. Chávez-Genaro ◽  
P. Lombide ◽  
G. Anesetti
Keyword(s):  
Quantitative Study ◽  
Post Partum ◽  
Sympathetic Innervation ◽  
Glyoxylic Acid ◽  
Late Pregnancy ◽  
Uterine Horn ◽  
Pregnant Rats ◽  
Tissue Sections ◽  
Hormonal Milieu

In mammals, pregnancy induces a transient and extensive degeneration of uterine sympathetic innervation. We used the models of unilateral oviduct ligation and in oculo myometrium transplant in pregnant rats to address the role of stretching forces and/or hormone milieu in the loss of sympathetic innervation. The sympathetic fibres of the uterine horn and in oculo myometrial transplants were quantified on tissue sections processed by the glyoxylic acid technique. In normal pregnant rats, the density of uterine horn innervation was significantly reduced at late pregnancy and recovery took place during post partum. The empty horn of pregnant rats showed no significant changes in density of myometrial innervation during pregnancy or post partum. In oculo myometrial transplants were organotypically reinnervated in virgin animals. When the transplants were exposed to gestational hormonal milieu, few or no fibres were observed to the end of pregnancy; however, a significant increase at post partum was observed. Results showed that both the effects of stretching and the hormone milieu derived from the fetus–placenta complex play a role as inductors of changes on sympathetic myometrial innervation during pregnancy and support the idea that immature muscular uterine fibres are more susceptible to the effects of pregnancy than those originating from adult animals.

scholarly journals Role of Insulin Receptor Substrate-1 Serine 307 Phosphorylation and Adiponectin in Adipose Tissue Insulin Resistance in Late Pregnancy

Endocrinology ◽  
2007 ◽  
Vol 148 (12) ◽  
pp. 5933-5942 ◽  
Author(s):  
Julio Sevillano ◽  
Javier de Castro ◽  
Carlos Bocos ◽  
Emilio Herrera ◽  
M. Pilar Ramos
Keyword(s):  
Insulin Resistance ◽  
Adipose Tissue ◽  
Insulin Receptor ◽  
Tyrosine Phosphorylation ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Late Pregnancy ◽  
Serine Phosphorylation ◽  
Pregnant Rats

Insulin resistance is a hallmark of late pregnancy both in human and rat. Adipose tissue is one of the tissues that most actively contributes to this reduced insulin sensitivity. The aim of the present study was to characterize the molecular mechanisms of insulin resistance in adipose tissue at late pregnancy. To this end, we analyzed the insulin signaling cascade in lumbar adipose tissue of nonpregnant and pregnant (d 20) rats both under basal and insulin-stimulated conditions. We found that the levels of relevant signaling proteins, such as insulin receptor (IR), IR substrate-1 (IRS-1), phosphatidylinositol 3-kinase, 3-phosphoinositide-dependent kinase-1, ERK1/2, and phosphatase and tensin homolog (PTEN) did not change at late pregnancy. However, insulin-stimulated tyrosine phosphorylation of both IR and IRS-1 were significantly decreased, coincident with decreased IRS-1/p85 association and impaired phosphorylation of AKR mouse thymoma viral protooncogene (Akt) and ERK1/2. This impaired activation of IRS-1 occurred together with an increase of IRS-1 phosphorylation at serine 307 and a decrease in adiponectin levels. To corroborate the role of IRS-1 in adipose tissue insulin resistance during pregnancy, we treated pregnant rats with the antidiabetic drug englitazone. Englitazone improved glucose tolerance, and this pharmacological reversal of insulin resistance was paralleled by an increase of adiponectin levels in adipose tissue as well as by a reduction of IRS-1 serine phosphorylation. Furthermore, the impaired insulin-stimulated tyrosine phosphorylation of IRS-1 in adipose tissue of pregnant animals could be restored ex vivo by treating isolated adipocytes with adiponectin. Together, our findings support a role for adiponectin and serine phosphorylation of IRS-1 in the modulation of insulin resistance in adipose tissue at late pregnancy.

Transcriptomes reveal alterations in gravity impact circadian clocks and activate mechanotransduction pathways with adaptation through epigenetic change

2015 ◽  
Vol 47 (4) ◽  
pp. 113-128 ◽  
Author(s):  
Theresa Casey ◽  
Osman V. Patel ◽  
Karen Plaut
Keyword(s):  
Gene Expression ◽  
Late Pregnancy ◽  
Global Gene Expression ◽  
Circadian Clocks ◽  
Epigenetic Change ◽  
Pregnant Rats ◽  
Affymetrix Genechips ◽  
Expression Of Genes ◽  
The Impact

Few studies have investigated the impact of alterations in gravity on mammalian transcriptomes. Here, we describe the impact of spaceflight on mammary transcriptome of late pregnant rats and the effect of hypergravity exposure on mammary, liver, and adipose transcriptomes in late pregnancy and at the onset of lactation. RNA was isolated from mammary collected on pregnancy day 20 from rats exposed to spaceflight from days 11 to 20 of gestation. To measure the impact of hypergravity on mammary, liver, and adipose transcriptomes we isolated RNA from tissues collected on P20 and lactation day 1 from rats exposed to hypergravity beginning on pregnancy day 9. Gene expression was measured with Affymetrix GeneChips. Microarray analysis of variance revealed alterations in gravity affected the expression of genes that regulate circadian clocks and activate mechanotransduction pathways. Changes in these systems may explain global gene expression changes in immune response, metabolism, and cell proliferation. Expression of genes that modify chromatin structure and methylation was affected, suggesting adaptation to gravity alterations may proceed through epigenetic change. Altered gravity experiments offer insights into the role of forces omnipresent on Earth that shape genomes in heritable ways. Our study is the first to analyze the impact of alterations in gravity on transcriptomes of pregnant and lactating mammals. Findings provide insight into systems that sense gravity and the way in which they affect phenotype, as well as the possibility of sustaining life beyond Earth's orbit.

OVARIAN ACTIVITIES OF PYRIDINE NUCLEOTIDE DEPENDENT DEHYDROGENASES IN THE RAT DURING PREGNANCY AND LACTATION

1968 ◽  
Vol 58 (3) ◽  
pp. 521-531
Author(s):  
T. Lunaas ◽  
R. L. Baldwin ◽  
P. T. Cupps
Keyword(s):  
Post Partum ◽  
Late Pregnancy ◽  
Pyridine Nucleotide ◽  
Corpora Lutea ◽  
Luteal Function ◽  
Wide Range ◽  
Pregnancy And Lactation ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Soluble Enzymes

ABSTRACT The activities of soluble enzymes catalyzing electron transfer in the systems malate:NADP, glucose-6-phosphate:NADP, 6-phosphogluconate: NADP, isocitrate:NADP and malate:NAD were determined in the ovaries of rats at several stages of reproduction. The enzymic activities (as μmol of product formed per min per g tissue) during late pregnancy (33 – 7 – 5 – 28 – 48, respectively) differed appreciably from the activities during the oestrous cycle (7 – 13 –3 – 30 – 25) and also at parturition (13 – 10 – 3 – 26 – 26). During pregnancy and parturition as well as during lactation and weaning there was an inverse relationship between the malate enzyme (malate:NADP) and the glucose-6-phosphate dehydrogenase. The ratio between the activities of these enzymes varied within a wide range (0.5 – 5) and appeared to reflect luteal function. The enzymic activities on day 6 of lactation in the involuted corpora lutea of pregnancy (7 – 15 – 3 – 41 – 32) and in the corpora lutea deriving from the post partum ovulation (15 – 7 – 4 – 39 – 36) were in agreement with this view. The possible role of the malate enzyme in the ovarian synthesis of steroids is discussed with reference to its presumed role in lipogenesis in the rat.

RELATIONSHIP BETWEEN INSULIN CONCENTRATIONS IN PLASMA AND PANCREAS OF FOETAL AND WEANLING RATS

1970 ◽  
Vol 48 (4) ◽  
pp. 553-561 ◽  
Author(s):  
E. BLÁZQUEZ ◽  
E. MONTOYA ◽  
CLEMENTE LÓPEZ QUIJADA
Keyword(s):  
Plasma Insulin ◽  
Striated Muscle ◽  
Slow Growth ◽  
Post Partum ◽  
Newborn Rat ◽  
Plasma Insulin Concentration ◽  
Pregnant Rats ◽  
Weanling Rats

SUMMARY During the third part of pregnancy in the rat the concentrations of plasma insulin and tissue glycogen in the foetus increase progressively. These levels and the release of insulin by pancreas incubated in vitro were significantly higher than the values found in adult non-pregnant rats. After birth the correlation between plasma insulin concentration and the stores of glycogen was also evident. In the first day of life, the concentrations of plasma insulin, glycogen in liver, striated muscle and kidney decreased significantly; these values decrease even more during the first 15 days of lactation. After weaning started (20 days post partum), rapid increases of insulin and glycogen were observed, parallel to the slow growth of the newborn rat during the first 15 days of life and the more rapid rate of growth after 20 days. Similarly, the insulin content of the pancreas increased more significantly during the period in which pancreatic weight and plasma insulin concentrations increased more slowly. These results show that when plasma insulin concentrations increase, body growth and stores of glycogen are higher, suggesting an anabolic role of insulin in the foetal and newborn rat.

scholarly journals Induction of expression and phosphorylation of heat shock protein B5 (CRYAB) in rat myometrium during pregnancy and labour

Reproduction ◽  
2016 ◽  
Vol 152 (1) ◽  
pp. 69-79 ◽  
Author(s):  
J G Nicoletti ◽  
B G White ◽  
E I Miskiewicz ◽  
D J MacPhee
Keyword(s):  
Heat Shock ◽  
Protein Expression ◽  
Post Partum ◽  
Focal Adhesions ◽  
Late Pregnancy ◽  
Immunoblot Analysis ◽  
Small Molecular Weight ◽  
Pregnant Rats ◽  
Immune System Activation ◽  
Cryab Protein

During pregnancy the myometrium undergoes a programme of differentiation induced by endocrine, cellular, and biophysical inputs. Small heat shock proteins (HSPs) are a family of ten (B1–B10) small-molecular-weight proteins that not only act as chaperones, but also assist in processes such as cytoskeleton rearrangements and immune system activation. Thus, it was hypothesized that HSPB5 (CRYAB) would be highly expressed in the rat myometrium during the contractile and labour phases of myometrial differentiation when such processes are prominent. Immunoblot analysis revealed that myometrial CRYAB protein expression significantly increased from day (D) 15 to D23 (labour;P<0.05). In correlation with these findings, serine 59-phosphorylated (pSer59) CRYAB protein expression significantly increased from D15 to D23, and was also elevated 1-day post-partum (P<0.05). pSer59-CRYAB was detected in the cytoplasm of myocytes within both uterine muscle layers mid- to late-pregnancy. In unilaterally pregnant rats, pSer59-CRYAB protein expression was significantly elevated in the gravid uterine horns at both D19 and D23 of gestation compared with non-gravid horns. Co-immunolocalization experiments using the hTERT-human myometrial cell line and confocal microscopy demonstrated that pSer59-CRYAB co-localized with the focal adhesion protein FERMT2 at the ends of actin filaments as well as with the exosomal marker CD63. Overall, pSer59-CRYAB is highly expressed in myometrium during late pregnancy and labour and its expression appears to be regulated by uterine distension. CRYAB may be involved in the regulation of actin filament dynamics at focal adhesions and could be secreted by exosomes as a prelude to involvement in immune activation in the myometrium.

Endothelium and aortic contraction to endothelin-1 in the pregnant rat

2000 ◽  
Vol 78 (5) ◽  
pp. 372-377 ◽  
Author(s):  
Amadou Moctar Dièye ◽  
Alexis Gairard
Keyword(s):  
Receptor Antagonist ◽  
Late Pregnancy ◽  
Female Rats ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Endothelin 1 ◽  
Key Words Endothelin ◽  
Vasoconstrictor Peptide ◽  
Aortic Contraction

Endothelium-derived factors modulate tone and may be involved in hyporeactivity to vasoconstrictors, such as norepinephrine or angiotensin II, as has been previously described during gestation. The endothelium produces endothelin-1, a major vasoconstrictor peptide, therefore aortic contractions to endothelin-1 (10-10 to 3 ×10-7 M) were used to assess the role of the endothelium in pregnant Wistar rats (at 20 days of gestation). Late pregnancy is characterized by a significantly diminished systolic blood pressure in conscious rats (-17 mmHg, P < 0.001, n = 14). In pregnant and in age-matched nonpregnant female rats, endothelin-1 induced aortic contraction was greater when endothelium was present (at least P < 0.01). Indomethacin significantly reduced this contraction in aortic rings with intact endothelium in all groups. In aortic rings that had endothelium physically removed, contraction to endothelin-1 was greater in pregnant rats than in nonpregnant ones. Indomethacin decreased contraction of aortic rings in pregnant rats only. These results suggest an enhanced synthesis of vasoconstrictors by cyclooxygenases in vascular smooth muscle during pregnancy. In vessels with intact endothelium, we did not find hyporeactivity to endothelin-1 during late pregnancy. Contraction to endothelin-1 involved ETA receptors because it was decreased by BQ-123, an ETA receptor antagonist, whereas there was no significant change when using BQ-788, an ETB receptor antagonist. Key words: endothelin-1, endothelium, contraction, aorta, gestation.

Serum concentrations of testosterone throughout pregnancy in rats

1982 ◽  
Vol 94 (1) ◽  
pp. 21-27 ◽  
Author(s):  
R. S. Bridges ◽  
R. B. Todd ◽  
C. M. Logue
Keyword(s):  
Post Partum ◽  
Late Pregnancy ◽  
Serum Testosterone ◽  
Serum Levels ◽  
Diurnal Variations ◽  
Serum Prolactin ◽  
Serum Concentrations ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Microcolumn Chromatography

Testosterone concentrations in serum of rats bled throughout pregnancy and post partum were measured using Celite microcolumn chromatography and a radioimmunoassay for testosterone. Mean serum levels of testosterone ranged from about 170 to 340 pmol/l during the first 10 days of pregnancy. Significant increases in concentrations of testosterone in serum of pregnant rats were found on days 12, 15 and 18 of gestation. The highest testosterone concentrations occurred on days 18 and 20 of pregnancy when mean levels were 3228 and 3685 pmol/l respectively. Testosterone levels declined before parturition on day 22 (mean = 1449 pmol/l and declined further after parturition (mean = 315 pmol/l). In order to determine whether serum testosterone concentrations varied during the day in the pregnant rat, samples were collected at 6-h intervals on days 6–7 and 14–15 of gestation. Diurnal variations in serum testosterone concentrations were not evident during early or late pregnancy, unlike the rhythmic changes in serum prolactin levels found at these times during early pregnancy. The possible sources of the increased titres of serum testosterone during the second part of gestation in rats are discussed.

scholarly journals Expression of small heat shock-related protein 20 (HSP20) in rat myometrium is markedly decreased during late pregnancy and labour

Reproduction ◽  
2007 ◽  
Vol 133 (4) ◽  
pp. 807-817 ◽  
Author(s):  
B E Cross ◽  
H M O’Dea ◽  
D J MacPhee
Keyword(s):  
Smooth Muscle ◽  
Heat Shock ◽  
Longitudinal Muscle ◽  
Post Partum ◽  
Muscle Relaxation ◽  
Late Pregnancy ◽  
Smooth Muscle Relaxation ◽  
Pregnant Rats ◽  
Longitudinal Muscle Layer ◽  
Mrna Detection

The underlying mechanisms regulating uterine contractions during labour are still poorly understood. Heat shock protein 20 (HSP20) is known to be present at high levels in smooth muscle and implicated in muscle relaxation, but HSP20 expression in the myometrium is completely undetermined. Since HSP20 has been implicated in smooth muscle relaxation, we hypothesized that HSP20 would be highly expressed in the rat myometrium during early and mid-pregnancy when the myometrium is relatively quiescent. Northern blot analysis particularly demonstrated that HSP20 mRNA detection was significantly decreased from day (d) 22 of pregnancy to 1-daypost-partum(PP) compared with d6 (P< 0.05). HSP20 mRNA detection was also significantly decreased from d22 to d23 of gestation compared with non-pregnant (NP) samples. Immunoblot analysis showed that detection of HSP20 was significantly decreased at d23 compared with d12 and d15 (P< 0.05). HSP20 detection also significantly decreased at PP compared with d15 (P< 0.05). Immunofluorescence analysis demonstrated that after d15, plasma membrane-associated localization of HSP20 decreased markedly in both circular and longitudinal muscle layers. In addition, HSP20 was detectable near cell membranes at much higher levels in the longitudinal muscle layer of progesterone-treated pregnant rats (delayed labour) at all gestational time points examined, compared with controls. Our results demonstrate that HSP20 mRNA and protein are highly expressed during early and mid-pregnancy and then the expression markedly decreases during late pregnancy and labour. The observed patterns of HSP20 expression are consistent with a potential role for HSP20 in facilitating myometrium quiescence during early and mid-pregnancy.

OESTRADIOL CONTENT OF OVARIAN VENOUS BLOOD AND OVARIAN TISSUE IN HYPOPHYSECTOMIZED RATS DURING LATE PREGNANCY

1972 ◽  
Vol 54 (1) ◽  
pp. 79-85 ◽  
Author(s):  
H. B. WAYNFORTH ◽  
D. M. ROBERTSON
Keyword(s):  
Corpus Luteum ◽  
Post Partum ◽  
Ovarian Tissue ◽  
Venous Blood ◽  
Late Pregnancy ◽  
Corpora Lutea ◽  
Pregnant Rats ◽  
Hypophysectomized Rats ◽  
Competitive Protein Binding ◽  
Intact Rats

SUMMARY Oestradiol-17β in ovarian venous blood and ovarian tissue was assayed by a competitive protein-binding method. Oestradiol was found in similar amounts in the ovarian vein blood of pregnant rats hypophysectomized on Day 12 and killed on Days 16 and 21 and in pregnant rats sham-hypophysectomized on Day 12 and killed on Day 16. The pituitary therefore plays no part in oestrogen production after mid-pregnancy until some time between Day 16 and Day 21, when it gives rise to an increased ovarian venous blood oestradiol content just before parturition, in intact sham-hypophysectomized rats. It is suggested that this increase is associated with the advent of the post-partum ovulation. The corpus luteum and the extraluteal component of the ovary in hypophysectomized rats autopsied on Days 16 and 21 and in sham-hypophysectomized rats autopsied on Day 16, contain similar amounts of oestradiol within each group. The extraluteal component contains about five times more oestradiol than corpora lutea in sham-hypophysectomized intact rats autopsied on Day 21. The ovaries of these animals also show an increased amount of oestradiol over that of the ovaries in the other three groups. It is suggested that secretion of oestradiol after mid-pregnancy in rats involves concurrently both the corpus luteum and the extraluteal component of the ovary.

scholarly journals Role of 17beta-estradiol and/or progesterone on insulin sensitivity in the rat: implications during pregnancy

2000 ◽  
Vol 166 (2) ◽  
pp. 283-291 ◽  
Author(s):  
C Gonzalez ◽  
A Alonso ◽  
N Alvarez ◽  
F Diaz ◽  
M Martinez ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Sensitivity ◽  
Insulin Action ◽  
Plasma Concentrations ◽  
Late Pregnancy ◽  
Ovariectomized Rats ◽  
Euglycemic Hyperinsulinemic Clamp ◽  
Pregnant Rats ◽  
Insulin Resistant

The mechanism for the development of insulin resistance in normal pregnancy is complex and is associated with serum levels of both progesterone and 17beta-estradiol. However, it remains unclear whether estrogens alone or progestins alone can cause insulin resistance, or whether it is a combination of both which produces this effect. We attempted to determine the role played by progesterone and/or 17beta-estradiol on the phenomena of sensitivity to insulin action that take place during pregnancy in the rat. Ovariectomized rats were treated with different doses of progesterone and/or 17beta-estradiol in order to simulate the plasma levels in normal pregnant rats. A euglycemic/hyperinsulinemic clamp was used to measure insulin sensitivity. At days 6 and 11, vehicle (V)- and progesterone (P)-treated groups were more insulin resistant than 17beta-estradiol (E)- and 17beta-estradiol+progesterone (EP)-treated groups. Nevertheless, at day 16, the V, EP and E groups were more resistant to insulin action than the P group. On the other hand, the V, EP and E groups were more insulin resistant at day 16 than at day 6, whereas the P group was more insulin resistant at day 6 than at day 16. Our results seem to suggest that the absence of female steroid hormones gives rise to a decreased insulin sensitivity. The rise in insulin sensitivity during early pregnancy, when the plasma concentrations of 17beta-estradiol and progesterone are low, could be due to 17beta-estradiol. However, during late pregnancy when the plasma concentrations of 17beta-estradiol and progesterone are high, the role of 17beta-estradiol could be to antagonize the effect of progesterone, diminishing insulin sensitivity.

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