scholarly journals Alteration in uterine contractility in mares with experimentally induced placentitis

Reproduction ◽  
2004 ◽  
Vol 127 (1) ◽  
pp. 57-66 ◽  
Author(s):  
J A McGlothlin ◽  
G D Lester ◽  
P J Hansen ◽  
M Thomas ◽  
L Pablo ◽  
...  
Keyword(s):  
Activity Index ◽  
Early Morning ◽  
Late Gestation ◽  
Uterine Contractility ◽  
Myoelectrical Activity ◽  
Spike Burst ◽  
Streptococcus Equi ◽  
Large Spike ◽  
Small Spike ◽  
Experimentally Induced

An experimental model of ascending placentitis was developed in the mare to characterize the uterine myoelectrical pattern in late gestation and determine how ascending placentitis altered this pattern. In experiment 1, myometrial electrical activity was analyzed during the early morning, late morning and evening hours in four mares in the last 15 days of gestation to identify patterns of activity. In experiment 2, nine mares received intra-cervical inoculations ofStreptococcus equisubspecieszooepidemicus. Myoelectrical activity in the early morning and evening hours in these mares was compared with four control mares. In experiment 1, the number of spike burst clusters >30 s was greater in the evening than in the late morning hours (P< 0.04). Spike burst activity (number × duration) of mares in experiment 1 was similar during day and night recordings until the last 6 days of gestation when it gradually increased each evening until parturition (P< 0.05). In experiment 2, control mares experienced a gradual increase in the number of small spike burst clusters in the last 6 days (P= 0.008) and an increase in large and small spike burst clusters in the evening hours in the last 4 days of gestation (P= 0.03). Mares with experimentally induced placentitis never exhibited a rise in spike burst clusters but had an increase in the mean duration and activity index of large spike burst clusters in the 4 days before parturition (P< 0.04). In conclusion, control mares had a progressive, reversible rise in myoelectrical activity at night in the week preceding parturition. This was not observed in mares with experimentally induced placentitis. They exhibited an increase in the intensity and duration of large spike burst clusters possibly in response to local inflammation.

scholarly journals Loss of prostaglandin F2α, but not thromboxane, responsiveness in pregnant human myometrium during labour

2008 ◽  
Vol 197 (1) ◽  
pp. 171-179 ◽  
Author(s):  
Deborah P Fischer ◽  
Jonathon A Hutchinson ◽  
Diane Farrar ◽  
Peter J O'Donovan ◽  
David F Woodward ◽  
...  
Keyword(s):  
Spontaneous Activity ◽  
Isometric Force ◽  
Area Under The Curve ◽  
Prostaglandin F2α ◽  
Late Gestation ◽  
Human Myometrium ◽  
Uterine Contractility ◽  
Arithmetic Means ◽  
Tp Receptors ◽  
Labour Onset

Prostaglandins (PG) E2, PGF2α and thromboxane (TX) mediate uterine contractility by targeting prostonoid EP, FP and TP receptors respectively. The aim of this study was to elucidate the function of these receptors in isolated human myometrium taken at term gestation prior to and following labour onset. Lower segment myometrial strips were immersed in organ baths in oxygenated Krebs' solution at 37 °C and connected to isometric force transducers. After equilibration, spontaneous activity and concentration responses to PGE2, PGF2α and U46619 (a stable TX mimetic) were measured as area under the curve and expressed as a percentage of the final contraction induced by hypotonic shock. Results were expressed as arithmetic means±s.e.m. and analysed using two-way ANOVA with Bonferroni's post hoc test. Myometrium excised at late gestation displayed the greatest spontaneous activity compared with the tissues taken during labour (P<0.001). Excitation evoked by PGF2α (P<0.01) and PGE2 at 10−5 mol/l were attenuated after labour onset. U46619 consistently stimulated concentration-dependent contractions (P<0.001) and selective antagonists confirmed TP-mediated effects. The maintained responses to TX indicate crucial roles for TP receptors in the muscular tonus of the parturient uterus. This receptor and its secondary messenger system represent effective myometrial targets for tocolytic agents in both pregnancy and labour-associated disorders.

The specific long spike burst pattern indicates the presence of regional variability in the ovine gallbladder motor function

Biologia ◽  
2017 ◽  
Vol 72 (12) ◽  
Author(s):  
Krzysztof Romański ◽  
Józef Nicpoń
Keyword(s):  
Small Bowel ◽  
Phase 1 ◽  
Force Transducer ◽  
Specific Pattern ◽  
Regional Variability ◽  
Burst Frequency ◽  
Myoelectrical Activity ◽  
Spike Burst ◽  
Burst Pattern ◽  
Rhythm Pattern

AbstractThe myoelectrical activity of ovine gallbladder is incompletely recognized. Accordingly, each of five rams was fitted with six small intestinal and three gallbladder electrodes. The strain gauge force transducer was also mounted near the gallbladder fundic electrode. In two series of chronic experiments the electromyographical and mechanical recordings were conducted during 5–7 h in fasted or non-fasted animals, with or without feeding. The occurrence of the slow waves in the small bowel was common, unlike those in the gallbladder. In the small bowel myoelectrical records both the migrating motility complex and minute rhythm pattern were observed regularly. In the gallbladder, both the migrating motility complex-like activity and the minute rhythm were also denoted in the same time as in the small bowel. In gallbladder infundibulum, and often also in the gallbladder corpus, the specific pattern, called the long spike burst pattern (LSBP) was observed. It comprised usually one or two parts of prolonged duration. The first part resembled the classical (short lasting) spike burst in the small bowel and its amplitude was lower than that of the second part. The spike burst frequency of the second part of the pattern was 2–3 times lower than that of the first part. During phase 1 – and phase 2a-like activity, the frequency of the gallbladder LSBP was reduced in fasted rams. The LSBP amplitude was relatively high and not further enhanced after feeding. In fasted rams, the duration of specific pattern, observed in gallbladder infundibulum, was longer than that in non-fasted animals and its amplitude was low. Similar events were recorded in the gallbladder corpus, but the LSBP was shorter and not regular. In the gallbladder fundus, mostly irregular short spike bursts were recorded. It is concluded that in sheep, specific types of the long-lasting groups of spikes occur in the upper gallbladder areas forming the specific pattern that indicates the presence of the regional variability of the gallbladder motor activity. The character of LSBP depends mostly on feeding conditions.

Relationships of maternal–fetal plasma steroid and amniotic fluid electrolyte levels to uterine myoelectrical activity during late gestation in sheep

1984 ◽  
Vol 62 (12) ◽  
pp. 2377-2382 ◽  
Author(s):  
D. D. Kitts ◽  
C. R. Krishnamurti
Keyword(s):  
Amniotic Fluid ◽  
Electrical Activity ◽  
Direct Relationship ◽  
Temporal Changes ◽  
Late Gestation ◽  
Myoelectrical Activity ◽  
Bipolar Electrodes ◽  
Fetal Plasma ◽  
Uterine Contractions ◽  
Uterine Electrical Activity

Paired bipolar electrodes were implanted in the corpus and uterotubal junctions in pregnant ewes. The temporal changes in uterine myoelectrical activity were monitored in conjunction with maternal and fetal plasma steroid and amniotic fluid electrolytes to evaluate the mechanisms regulating the prepartal uterine contractions in the ewe. Increases in total uterine myoelectrical activity were significant (P < 0.001) at both uterine locations as term approached, although significant (P < 0.01) variation existed between individual animals. Significant correlations between maternal progesterone (P < 0.05) and maternal and fetal estrogens (P < 0.01) and uterine myoelectrical activity were observed. The decline in maternal progesterone to levels of 2.03 ± 0.4 ng/mL and concomitant increases in both maternal and fetal total estrogens (199.3 ± 4.7 and 262.5 ± 11.0 pg/mL, respectively) resulted in a relatively high maternal estrogen/progesterone ratio just prior to parturition and corresponded to an approximate fivefold increase in total uterine electrical activity. Fetal cortisol concentrations were not significantly correlated with uterine myoelectrical activity; however, a positive correlation (P < 0.05) between fetal cortisol and maternal estrogen/progesterone ratios was obtained. The results of this study demonstrate a direct relationship between changes in the maternal estrogen/progesterone ratios and frequency and patterns of uterine electrical signals just prior to parturition, which may be ultimately triggered by the surge in fetal corticosteroid production.

scholarly journals An application of higher order multivariate cumulants in modelling of myoelectrical activity of porcine uterus during early pregnancy

2018 ◽  
Author(s):  
Malgorzata Domino ◽  
Krzysztof Domino ◽  
Zdzislaw Gajewski
Keyword(s):  
Early Pregnancy ◽  
Reproductive Tract ◽  
Computational Modelling ◽  
Higher Order ◽  
Dependence Structure ◽  
Preclinical Model ◽  
Human Beings ◽  
Uterine Contractility ◽  
Myoelectrical Activity ◽  
Emg Signal

ABSTRACTThe analysis of the uterine contraction have become a general practice in an effort to improve the clinical management of uterine contractions during pregnancy and labour in human beings. The fluctuations in uterine activity may occur without affecting progress of gestation, however the painful and fashion contractions may be the first threat of miscarriage. While pigs were considered as an referential preclinical model, the computational modelling of spontaneous myoelectrical activity of complex systems of porcine myometrium in peri-fertilization period has been proposed. The higher order statistic, multivariate cumulants and Joint Skewness Band Selection method, have been applied to study the dependence structure of electromyographic (EMG) signal with an effective EMG feature. Than the model of recognition of multivariate, myoelectricaly changes according to crucial stages for successful fertilization and early pregnancy maintenance has been estimated. We found that considering together time and frequency features of EMG signal was extremely non-Gaussian distributed and the higher order multivariate statistics such as cumulants, have to be used to determine the pattern of myoelectrical activity in reproductive tract. We confirmed the expectance that the probabilistic model changes on a daily base. We demonstrated the changes in proposed model at the crucial time points of in peri-fertilization period. We speculate the activity of the middle of uterine horn and the power (minimum and maximum) and pauses between myoelectrical burst features are essential for the functional role of uterine contractility in peri-fertilization period.

Fetal-fluid proteome analyses in late-term healthy pregnant mares and in mares with experimentally induced ascending placentitis

2019 ◽  
Vol 31 (9) ◽  
pp. 1486 ◽  
Author(s):  
Igor F. Canisso ◽  
Shavahn Loux ◽  
Kirsten E. Scoggin ◽  
Edward L. Squires ◽  
Mats H. Troedsson ◽  
...  
Keyword(s):  
Calcium Binding ◽  
Protein Composition ◽  
Allantoic Fluid ◽  
Signalling Molecules ◽  
Disease States ◽  
Streptococcus Equi ◽  
Before And After ◽  
Fetal Fluid ◽  
Fetal Fluids ◽  
Experimentally Induced

Characterisation of fetal fluids in healthy and disease states of pregnant mares can help to unravel the pathophysiology and to identify putative markers of disease. Thus, this study aimed to compare the protein composition of: (1) amniotic and allantoic fluids of healthy mares obtained immediately after euthanasia and (2) allantoic fluid harvested via centesis before and after experimental induction of placentitis via transcervical inoculation of Streptococcus equi ssp zooepidemicus in healthy mares. Fetal fluids were analysed with a high-throughput proteomic technique after in-gel digestion. Statistical comparisons were performed following normalisation of peptide spectral match. Global normalisation was performed to calculate relative expression. There were 112 unique proteins present in both allantoic and amniotic fluids. There were 13 and 29 proteins defined as amniotic- or allantoic-specific respectively that were present in at least two fluid samples. Another 26 proteins were present in both amniotic and allantoic fluids. Panther DB functional classification grouped fetal-fluid proteins as transfer carriers, signalling molecules, receptors, immunity, hydrolase, enzymes, membrane traffic, cytoskeleton, cell adhesion, calcium binding and extracellular matrix. Experimentally induced placentitis resulted in 10 proteins being upregulated and 10 downregulated in allantoic fluid. Newly identified proteins and changes in the fetal-fluid proteome provide clues about the physiology of pregnancy and pathogenesis of placentitis.

Changes in jejunal myoelectrical activity during exercise in fed untrained dogs

1988 ◽  
Vol 254 (5) ◽  
pp. G741-G747
Author(s):  
M. J. Kenney ◽  
A. Flatt ◽  
R. W. Summers ◽  
C. K. Brown ◽  
C. V. Gisolfi
Keyword(s):  
Gastrointestinal Symptoms ◽  
Proximal Jejunum ◽  
Regular Spike ◽  
Short Term ◽  
Burst Frequency ◽  
Myoelectrical Activity ◽  
Spike Burst ◽  
Bipolar Electrodes ◽  
Exercise Induced ◽  
Spike Bursts

Seven female dogs (15-20 kg) were instrumented with seven bipolar electrodes sutured at 3-cm intervals to the serosal surface of the proximal jejunum and were exercised at different intensities and durations on a motor-driven treadmill. Slow-wave frequency increased (P less than 0.05) from preexercise control during prolonged (90 min) exercise and during recovery after short-term exercise (30 min) at 70% heart rate reserve (HRR). These changes were associated with an increase in core temperature. Spike-burst frequency (SBF) increased (P less than 0.05) with moderate exercise (50% HRR), but the magnitude was small. When exercise was extended beyond 30 min and during all recovery periods, SBF decreased significantly. Exercise produced migrating myoelectrical complexes in three experiments and less dramatic pattern changes characterized as "clustered contractions" (regular spike bursts preceded and followed by the absence of spike bursts) in at least nine other experiments. We conclude that exercise does alter jejunal myoelectrical activity, but myoelectrical patterns may be more important in explaining exercise-induced gastrointestinal symptoms than changes in spike-burst frequency or duration.

Ontogeny of estrogen sulfatase activity in ovine fetal hypothalamus, hippocampus, and brain stem

1999 ◽  
Vol 276 (6) ◽  
pp. R1647-R1652 ◽  
Author(s):  
Scott C. Purinton ◽  
Howard Newman ◽  
Maria I. Castro ◽  
Charles E. Wood
Keyword(s):  
Brain Stem ◽  
Late Gestation ◽  
Ventrolateral Medulla ◽  
Uterine Contractility ◽  
Developmentally Regulated ◽  
Fetal Plasma ◽  
Estrone Sulfate ◽  
Sulfatase Activity ◽  
Estrogen Sulfatase ◽  
Ovine Fetal

Ovine parturition is initiated by increases in fetal hypothalamus-pituitary-adrenal (HPA) axis activity, which in turn increase placental estrogen biosynthesis and ultimately increase uterine contractility. In addition to the action in the uterus, estrogens augment fetal ACTH secretion. In late gestation, estrone sulfate is more abundant in fetal plasma than is unconjugated estrone. We studied hypothalamus, hippocampus, and brain stem tissue from fetal, neonatal, and adult sheep to test the hypothesis that the ovine brain contains estrogen sulfatase activity. We found that the activity in the hippocampus was significantly increased in late-gestation fetuses compared with both younger and older animals. No significant change in either hypothalamus or brain stem was revealed; however, the activity in all brain areas was high. Immunohistochemistry revealed the presence of estrogen sulfatase in the paraventricular nucleus of the hypothalamus, the nucleus of the solitary tract, and the rostral ventrolateral medulla. We conclude that ovine fetal hypothalamus, hippocampus, and brain stem contain estrogen sulfatase activity and that the activity in the hippocampus is developmentally regulated.

Evaluation of calcium to phosphorus ratio in spot urine samples as a practical method to monitor phosphorus intake adequacy in sows

2021 ◽  
Author(s):  
Mariola Grez-Capdeville ◽  
Thomas D Crenshaw
Keyword(s):  
Physiological State ◽  
Roc Curves ◽  
Strong Relationship ◽  
Weighted Kappa ◽  
Practical Method ◽  
Early Morning ◽  
Late Gestation ◽  
Urine Samples ◽  
Spot Urine ◽  
Phosphorus Intake

Abstract The objective of this study was to evaluate the reliability of using Ca to P ratio measured in spot urine samples to assess P intake adequacy in gestating and lactating sows. A total of 36 sows were fed one of six concentrations of dietary total P (0.40, 0.48, 0.56, 0.64, 0.72, 0.80%) from day 7.5 + 1 after breeding until the end of lactation (day 26.6 + 1). Dietary Ca to P ratio was maintained constant across treatments at 1.25. Total 24-hour urine samples were collected in mid and late gestation (days 77.1 + 2 and 112.4 + 1), and early and late lactation (days 4.5 + 1 and 18.2 + 1). In parallel to 24-hour collections, spot urine samples were collected at three different times (early morning, late morning, and late afternoon) in late gestation and late lactation. Urine Ca and P concentrations were measured and Ca to P ratio was calculated. Sows were classified as P-adequate or P-deficient according to dietary P intake. Urine Ca to P ratio was greater in sows fed P-deficient diets than sows fed P-adequate diets (P &lt; 0.001). Receiver operator characteristic (ROC) curves were used to determine the cut-off values for urine Ca to P ratio to predict P intake adequacy. Three different categories of P intake were defined according to urine Ca to P ratio: deficient, adequate, and excessive. The area under the ROC for Ca to P ratio was 0.88 (95% CI 0.81 – 0.95). Best cut-off value of urine Ca to P ratio was 1.5 (sensitivity 94% and specificity 68%) to identify sows fed P-deficient diets and 0.5 for P-excessive diets (sensitivity 82% and specificity 82%). A strong relationship between Ca to P ratio in 24-hour and spot urine samples was determined (r = 0.93, P &lt; 0.01), independent of physiological state and collection time of spot samples (adjusted-R 2 = 0.86, P &lt; 0.01). The degree of agreement between spot and 24-hour urine for P intake adequacy, assessed by Cohen’s weighted kappa analysis, was substantial (0.78, 95% CI 0.69 – 0.88). We conclude that urinary Ca to P ratio provides a reliable prediction of the adequacy of P intake in reproducing sows. Urinary Ca to P ratio measurements in random spot urinary offers a practical method to determine dietary P adequacy.

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