Bovine Prenatal Development: A Comparative Study of Ultrasonography and Radiography Techniques

This study was undertaken with the aim of assessing the use of high frequency transducer (7.5 MHz) and a quality ultrasound scanner in the study of in-uterine bovine fetal development i.e. bovine fetal age determination and the ultrasonographic anatomy of the gross tissues and organs of the developing bovine fetus, particularly the stomach compartments, between gestational age 45-90 days. Additionally, ultrasonography was compared to radiography and bone staining techniques, in the study of fetal osteogenesis. The simple regression, polynomial and logarithmic mathematical models were used to examine and analyse in depth, the growth rate and patterns of crown rump length, biparietal diameter and trunk diameter. Each model was tested for fitness of the raw data, precision to predict age and ability to describe the various characteristics of the growth curve of fetal parameters. On average, crown rump length had the fastest growth rate and the least variance, while, trunk diameter had the slowest growth rate and the highest variance of the three fetal parameters analysed. The best mathematical model, out of the three, for crown rump length, in terms of fitness of the raw data and precision to determine fetal age, was the logarithmic model. The linear model was good at giving an overall impression of the average growth rate and steepness of the growth curve. The model with the best fit of the raw data of biparietal diameter and the most precise in determining fetal age was the polynomial model. No major difference in the growth rate and size was noted between the width and depth of the trunk diameter and between sizes of trunk diameter taken at the level of the umbilicus and the stomach This study did not find any major difference of statistical significance between growth curves of embryo transfer fetuses and normal fetuses. The linear model was the simplest of the three models assessed: deriving the age prediction equation and identifying the features of growth that the coefficients represented was easier than with the other two models. It could also be used to ascertain the average growth rate during a given period. However, it could only be used in linear growth curves, usually present in early gestation and not non-linear characteristics seen in a typical growth pattern of later pregnancy. The polynomial model had three coefficients, and hence is more complex to interpret and derive age prediction equations, compared to the other two models. It is, therefore, not, in most cases, a good model to use for the purpose of estimating age. However, it was very good at defining and describing the extent and direction of both linear and curvature features of the growth curves. It did not, however, specify the points at which these curvings begin and end on the growth curve. The two coefficients of logarithmic model are relatively easy to interpret and to derive age prediction equation. It was the most ideal for the purpose of estimating age using fetal dimensions which have typical curvilinear or sigmoid growth curves, because it was able to transform nonlinear raw data into linear and has uniform variations and hence, the least coefficient of variation . No difference, in precision, in determining age of in-uterine bovine fetus between transducers with higher frequency and (7.5 MHz) and those of lower frequencies was found (3.5 and 5.0 MHz.), based on early bovine fetal development. The improvement of precision in fetal aging and a clearer understanding of growth patterns may depend, among other things, on the use of an appropriate age prediction model, at a given age and not so much on the use of transducers of higher frequencies. Sonographic images of almost all the major fetal structures, like the brain, orbit, maxilla, mandible, heart, blood vessels, stomach, hind and forelimbs, were identified by Day 45 of gestation. Sonographic images of the stomach could be identified by Day 39 of gestation, although it was not possible to recognise the differentiation of the stomach compartments until after Day 53 of gestation. The first compartment of the stomach identifiable sonographically was the reticulo-rumen. Differentiation of the rumen into its various sacs became apparent by Day 60 of gestation. Differentiation of the omasum first appeared as a round hyperechogenic structure by Day 53 of pregnancy. The laminae omasi appeared one week later. Other structures of the omasum identified included the esophageal groove and omasi sulci by Day 70 of gestation. The most difficult stomach compartment to identify was the abomasum, because of the close resemblance of its images and its proximity to the intestines. The reticulum was imaged by Day 76 of pregnancy and structures scanned immediate to it were; the liver and diaphragm, cranially, the vestibule of the rumen, caudally and the omasum on the right. The sensitivity of ultrasonography and radiography techniques in detecting the earliest time and chronological order of appearance of the loci of ossification were found to be the same

Endothelin Antagonism Normalizes VEGF Signaling And Cardiac Function In STZ-Induced Diabetic Rat Hearts

Abnormal alterations in cardiac expression of vascular endothelial growth factor (VEGF) as well as its receptors and impairment in the development of coronary collaterals have recently been reported in diabetic subjects. However, the presence of pharmacological intervention on these defects in diabetes remains unsettled. Here, we studied the effect of endothelin (ET) receptor blockade on cardiac VEGF signaling pathways and cardiac function in Sprague-Dawley rats 5 wk after induction of type I diabetes with streptozotocin (65 mg/kg ip) in comparison with age- matched control rats. After streptozotocin (1 wk), some diabetic rats were treated with the ET receptor antagonist SB-209670 (1 mg/day) for 4 wk. VEGF, its receptors, and its angiogenic signaling molecules [phosphorylated Akt and endothelial nitric-oxide synthase (eNOS)] were analyzed by Western blot, ELISA, real-time PCR, and immu- nohistochemistry, and cardiac function was evaluated by echocardi- ography. Coronary capillary morphology was assessed by lectin and enzymatic double staining. We found significant decreases in cardiac expression of VEGF, its receptors, phosphorylation of Akt and eNOS, and coronary capillary density in diabetic rats compared with controls. Treatment of diabetic rats with SB-209670 reversed these alterations to the control levels and ameliorated impairment of cardiac function. From a molecular point of view, the present study is the first to indicate the potential usefulness of an ET receptor antagonist in the treatment of cardiac dysfunction in type I diabetes

Expression Of Pituitary Adenylate Cyclase Activating Peptide In The Uterine Cervix, Lumbosacral Dorsal Root Ganglia And Spinal Cord Of Rats During Pregnancy

The uterine cervix is highly innervated by the sensory nerves containing neuropeptides which change during pregnancy and are regulated, in part, by estrogen. These neuropep- tides act as transmitters both in the spinal cord and cervix. The present study was under- taken to determine the expression pattern of the neuropeptide pituitary adenylate cyclase activating peptide (PACAP) in the cervix and its nerves during pregnancy and the influence of estrogen on this expression using immunohistochemistry, radioimmunoassay and RT- PCR. PACAP immunoreactivity was detected in nerves in the cervix, lumbosacral (L6-S1) dorsal root ganglia (DRG) and spinal cord. PACAP immunoreactivity was highest at day 15 of pregnancy in the cervix and dorsal spinal cord, but then decreased over the last trimester of pregnancy. However, levels of PACAP mRNA increased in the L6-S1 DRG at late pregnancy relative to early pregnancy. DRG of ovariectomized rats treated with estrogen showed increased PACAP mRNA synthesis in a dose-related manner, an effect partially blocked by the estrogen receptor (ER) antagonist ICI 182 780. We postulate that synthesis of PACAP in L6-S1 DRG and utilization in the cervix and spinal cord increase over pregnancy and this synthesis is the under influence of the estrogen-ER system. Since PACAP is expressed by sensory nerves and may have roles in nociception and vascular function, collectively, these data are consistent with the hypothesis that sensory nerve-derived neuronal factors innervate the cervix and play a role in cervical ripening

Dual Blockade Of Endothelin Action Exacerbates Up-Regulated VEGF Angiogenic Signaling In The Heart Of Lipopolysaccharide-Induced Endotoxemic Rat Model

Aims: Sepsis is a cluster of heterogeneous syndromes associated with progressive endotoxemic developments, ultimately leading to damage of multiple organs, including the heart. However, the pathogenesis of sepsis-induced myocardial dysfunction is still not fully understood. The present study is the first to examine alterations in expression of key angiogenic signaling system mediated by vascular endothelial growth factor (VEGF) in septic heart and the effects of endothelin dual blocker (ETDB) on it. Main methods: Normal Wistar rats were either administered with: a) vehicle only (control group), b) lipopolysaccharide only (LPS: 15 mg/kg) and then sacrificed at different time points (1 h, 3 h, 6 h and 10 h), and c) the last group was co-administered with LPS and ETDB (SB-209670, 1 mg/kg body weight) for 6 h and then sacrificed. Key findings: Administration of LPS resulted in increases in levels of: a) serum tumor necrosis factor (TNF)-a, serum VEGF and c) serum endothelin (ET)-1 levels accompanied by up-regulation of cardiac VEGF and its downstream angiogenic signaling molecules. While cardiac TNF-a level was unchanged among experimental groups, cardiac ET-1 level was significantly higher in LPS-administered group.Significance: We conclude that elevation in VEGF angiogenic signaling may be triggered by diminished oxygenation in the myocardium following LPS administration as a consequence of sepsis-induced microvascular dysfunction. Because of this cardiac dysfunction, oxygen supply may be inadequate at microregional level to support the normal heart metabolism and function. ETDB at 6 h further increased the elevated levels of VEGF angiogenic signaling in endotoxemic heart

Evidence For A Potential Role Of Estrogen In The Penis: Detection Of Estrogen Receptor-A And -B Messenger Ribonucleic Acid And Protein

Body tissues are traditionally classified as estrogen targets based on both the response to the hormone and the presence of estrogen receptors (ERs). We undertook the study on expression of ERff and ERb in the penis to identify compartments/cells responsive to estrogen, using immunohistochemistry, Western blotting, in situ hybridization, and RT-PCR analyses. Expressions of ERa and ERb in the rat penis were age dependent at both mRNA and protein levels, with the most intense signals being observed during the perinatal period and declining thereafter with age. Initial signals (fetal d 17) of ERff were localized to the mesenchyme and subepithelial stroma and later (postnatal d 2) to the corpus spongiosus, corpus cavernosus, and urethral epithelia. ERb was initially detected by postnatal d 2 and was localized diffusely in corpus spongiosus and cavernosus in immature rats. In the adult, both ERs were concentrated largely to the urethral epithelia and vascular and neuronal structures. The present study provides the first evidence for ER expression in the penis. Thus, our data add the penis to the list of estrogen-responsive tissues in males and provide a base and insight for future studies aimed at investigating a functional role of estrogen in the penis, especially in development

Postpartum Cervical Repair In Mice: A Morphological Characterization And Potential Role For Angiogenic Factors

The cervix undergoes marked mechanical trauma during delivery of the baby at birth. As such, a timely and complete tissue repair postpartum is necessary to prevent obstetrical complications, such as cervicitis, ectropion, hemorrhage, repeated miscarriages or abortions and possibly pre- term labor and malignancies. However, our knowledge of normal cervical repair is currently incomplete and factors that influence repair are unclear. Here, we characterize the morphological and angiogenic profile of postpartum repair in mice cervix during the first 48 h of postpartum. The key findings presented here are: (1) cervical epithelial folds and size are diminished during the first 48 h of postpartum repair, (2) hypoxic inducible factor 1a, vascular endothelial growth factor (VEGF), and VEGF receptor 1 expression are pronounced early in postpartum cervical repair, and (3) VEGF receptor 2 gene and protein expressions are variable. We conclude that postpartum cervical repair involves gross and microscopic changes and is linked to expression of angiogenic factors. Future studies will assess the suitability of these factors, identified in the present study, as potential markers for determining the phase of postpartum cervical repair in obstetrical complications, such as cervical lacerations

Expression Of Steroidogenic Enzymes And Synthesis Of Sex Steroid Hormones From DHEA In Skeletal Muscle Of Rats

The functional importance of sex steroid hormones (testosterone and estrogens), derived from extragonadal tissues, has recently gained signi?cant appreciation. Circulating dehydroepiandrosterone (DHEA) is peripherally taken up and converted to testosterone by 3-hydrox-ysteroid dehydrogenase (HSD) and 17-HSD, and testosterone in turn is irreversibly converted to estrogens by aromatase cytochrome P-450 (P450arom). Although sex steroid hormones have been implicated in skeletal muscle regulation and adaptation, it is unclear whether skel-etal muscles have a local steroidogenic enzymatic machinery capable of metabolizing circulating DHEA. Thus, here, we investigate whether the three key steroidogenic enzymes (3-HSD, 17-HSD, and P450arom) are present in the skeletal muscle and are capable of generating sex steroid hormones. Consistent with our hypothesis, the present study demonstrates mRNA and protein expression of these enzymes in the skeletal muscle cells of rats both in vivo and in culture (in vitro). Importantly, we also show an intracellular formation of testosterone and estradiol from DHEA or testosterone in cultured muscle cells in a dose-dependent manner. These ?ndings are novel and important in that they provide the ?rst evidence showing that skeletal muscles are capable of locally synthesizing sex steroid hor-mones from circulating DHEA or testosterone

Effects Of Protease Activated Receptor (PAR)2 Blocking Peptide On Endothelin-1 Levels In Kidney Tissues In Endotoxemic Rat Model

Aims: Septic shock, the severe form of sepsis, is associated with development of progressive damage in multiple organs. Kidney can be injured and its functions altered by activation of coagulation, vasoactive-peptide and inflammatory processes in sepsis. Endothelin (ET)-1, a potent vasoconstrictor, is implicated in the pathogenesis of sepsis and its complications. Protease-activated receptors (PARs) are shown to play an important role in the interplay between inflammation and coagulation. We examined the time-dependent alterations of ET-1 and inflammatory cytokine, such as tumor necrosis factor (TNF)-a in kidney tissue in lipopolysaccharide (LPS)-induced septic rat model and the effects of PAR2 blocking peptide on the LPS-induced elevations of renal ET-1 and TNF-a levels.Main methods: Male Wistar rats at 8 weeks of age were administered with either saline solution or LPS at different time points (1, 3, 6 and 10 h). Additionally, we treated LPS-administered rats with PAR2 blocking peptide for 3 h to assess whether blockade of PAR2 has a regulatory role on the ET-1 level in septic kidney. Key fndings: An increase in ET-1 peptide level was observed in kidney tissue after LPS administration time-dependently. Levels of renal TNF-a peaked (around 12-fold) at 1 h of sepsis. Interestingly, PAR2 blocking peptide normalized the LPS-induced elevations of renal ET-1 and TNF-a levels.Significance: The present study reveals a distinct chronological expression of ET-1 and TNF-a in LPS-administered renal tissues and that blockade of PAR2 may play a crucial role in treating renal injury, via normalization of inflammation, coagulation and vaso-active peptide

Antagonism Of Endothelin Action Normalizes Altered Levels Of VEGF And Its Signaling In The Brain Of Stroke-Prone Spontaneously Hypertensive Rat

Stroke-prone spontaneously hypertensive rats (SHRSP) often suffer from spontaneous stroke, in part, due to abnormalities in the cerebrovasculature. Here, we investigate the profile of key angiogenic factors and their basic signaling molecules in the brain of SHRSP during the age-dependent stages of hypertension. The profile of VEGF and its receptor, Flk-1, was dependent on age and stage of hypertension (i.e., down regulated at pre-hypertensive and malignant hypertensive stages, but up regulated at typical hypertensive stage), while that of its downstream components, pAkt and eNOS, were down regulated in a time-dependent manner in the frontal cortex of SHRSP compared to age-matched genetic control, normotensive WKY rats. On the other hand, the expression of endothelin-1 and its type A receptor (endothelin ETA receptor) were up regulated, depending on age and stage of hypertension. In contrast, levels of endothelin type B receptor were down regulated. The regional cerebral blood flow decreased during the development of malignant hypertension. Thus, subsequent experiments were designed to investigate whether endothelin-1 receptor antagonism, using endothelin-A/-B dual receptor antagonist SB209670, could normalize the molecular profile of these factors in SHRSP brain. Interestingly, blockage of endothelin-1 receptor restored to normal, levels of cerebral endothelin-1, endothelin ETA receptor and endothelin ETB receptor; VEGF and Flk-1; endothelial nitric oxide synthase (eNOS) and pAkt, in SHRSP, compared to age-matched WKY. Endothelin receptor blocker might be important to prevent the progression in the defect in VEGF and its angiogenic signaling cascade in the pathogenesis of hypertension-induced vascular remodeling in frontal cortex of SHRSP rats

Landiolol Hydrochloride Ameliorates Acute Lung Injury In A Rat Model Of Early Sepsis Through The Suppression Of Elevated Levels Of Pulmonary Endothelin-1

Among the dysfunctions and pathologies associated with sepsis, the underlying molecular mechanisms of sepsis-induced acute lung injury (ALI) are poorly understood. Endothelin (ET)-1, a potent vasoconstrictor and pro-inflammatory peptide, is known to be involved in the pathogenesis of ALI in a rat model of sepsis. Here, we investigated whether landiolol hydrochloride, an ultra-short-acting ß-blocker, plays a crucial role in ameliorating and attenuating LPS-induced ALI through modulation of the ET-1 system. Male Wistar rats at 8 weeks of age were ad-ministered with either saline or lipopolysaccharide (LPS) for three hours (3 h) and some of the LPS-administered rats were continuously treated with landiolol for 3 h. ALI was induced by LPS, including levels of both circulatory and pulmonary TNF-a and IL-6 but [PaO2]was significantly decreased. LPS also induced a signi?cant increase in levels of pulmonary ET-1 and ET-A receptor, but levels of ET-B receptor, which has vasodilating effects, were remarkably diminished. Further, LPS administration upregulated the pulmonary expression of HIF-1a.Finally, the treatment of LPS-administered rats with landiolol for 3 h ameliorated and prevented ALI, normalized the altered levels of pulmonary ET-1 and ET-A receptors. Landiolol also induced significant down-regulation of ET-B receptor in lung tissues in the early hours (phase) of sepsis. However, Landiolol treatment had no effect on the up-regulated inflammatory mediators (TNF-a, IL-6) in both plasma and lung tissues during sepsis, and expression of pulmonary HIF-1a also remained unchanged after landiolol treatment. Collectively, these data led us to conclude that landiolol may ameliorate sepsis-induced ALI via the pulmonary ET system