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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Activation of oxytocin (OT)ergic projections from the hypothalamic paraventricular nucleus (PVN) to the nucleus tractus solitarii contributes to cardiovascular adjustments during exercise training (EXT). Moreover, a deficit in this central OTergic pathway is associated with altered cardiovascular function in hypertension. Since PVN catecholaminergic inputs, known to be activated during EXT, modulate PVN cardiovascular-related functions, we aimed here to determine whether remodeling of PVN (nor)adrenergic innervation occurs during EXT and whether this phenomenon is affected by hypertension. Confocal immunofluorescence microscopy and tract tracing were used to quantify changes in (nor)adrenergic innervation density in PVN subnuclei and in identified dorsal vagal complex (DVC) projecting neurons (PVN-DVC) in EXT normotensive [Wistar-Kyoto rat (WKY)] and hypertensive [spontaneously hypertensive rat (SHR)] rats. In WKY, EXT increased the density of PVN dopamine beta-hydroxylase immunoreactivity (DBHir) (160%). Furthermore, the number and density of DBHir boutons overlapping PVN-DVC OTergic neurons were also increased during EXT (130%), effects that were blunted in SHR. Conversely, while DBHir in the medial parvocellular subnucleus (an area enriched in corticotropin-releasing hormone neurons) was not changed by EXT in WKY, a diminished DBHir was observed in trained SHR. Overall, these data support the concept that the PVN (nor)adrenergic innervation undergoes plastic remodeling during EXT, an effect that is differentially affected during hypertension. The functional implications of PVN (nor)adrenergic remodeling in relation to the central peptidergic control of cardiovascular function during EXT are discussed.
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PMID:Exercise training-induced remodeling of paraventricular nucleus (nor)adrenergic innervation in normotensive and hypertensive rats. 1721 43

Dopamine receptors have been identified in a number of organs and tissues, which include the central and peripheral nervous systems, various vascular beds, the heart, the gastrointestinal tract, and the kidney. Dopamine receptors are classified into D1- and D2- like subtypes based on their structure and pharmacology; during conditions of moderate sodium balance, more than 50% of renal sodium excretion is regulated by D1-like receptors. Most of the knowledge on the actions of dopamine has been focused on the D1 dopamine receptor. The D5 dopamine receptor also belongs to the D1- like receptor subfamily. Disruption of the D5 receptor results in hypertension. However, unlike the D1 receptor, the hypertension in D5 receptor null mice is caused by the increased activity of the sympathetic nervous system, apparently due to activation of oxytocin, V1 vasopressin, and non-NMDA receptors in the central nervous system. In this paper, we review the physiological action of D5 receptor on the central and peripheral nervous systems, and discuss the possible mechanisms by which hypertension develops when the D5 receptor function is perturbed.
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PMID:Regulation of blood pressure by D5 dopamine receptors. 1763 Sep 51

We report the successful use of vasopressin in the management of hypotension in association with severe right ventricular (RV) failure in two patients with advanced idiopathic pulmonary arterial hypertension. Both patients were pregnant and developed systemic hypotension after delivery by Caesarean section. Placental autotransfusion and possibly oxytocin use were thought to be the major contributing factors in worsening RV function. After the use of vasopressin in both patients, cardiovascular variables improved without untoward effect on RV function, and provided rescue therapy for systemic hypotension in this setting. Vasopressin, a direct vasopressor acting via V1 receptors on the vascular endothelium, has been shown to cause pulmonary vasodilatation experimentally and in animal models of pulmonary hypertension. Its synthetic analogue, terlipressin, has been shown to reduce pulmonary vascular resistance in humans with cirrhosis. Vasopressin may therefore have differential effects on the pulmonary and systemic circulations, allowing systemic pressure to be supported without detrimental effects on the pulmonary circulation.
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PMID:Use of vasopressin after Caesarean section in idiopathic pulmonary arterial hypertension. 1766 Apr 58

The purpose of this review is to summarize the available evidence on occipito-posterior fetal head position and maternal and neonatal outcome. The occipito-posterior fetal head position is the most common malposition, but there are not so many data about it in literature. Its incidence is ranging from 1.8% by Fitzpatrick, to 4.6% and 5.5% by Yancey and Sizer, to 6% by Ponkey. Only two trials studied the occipito-posterior associated factors. There are lower incidence of premature rupture of membrane, arterial hypertension pregnancy-induced, induced labour, increased of episiotomy, instrumental delivery and a decreased of vaginal birth without a difference in neonatal Apgar, and with a neonatal bigger weight. The occipito-posterior fetal head position persistence compared to anterior position, has a statistically significant association with low maternal stature, previous cesarean section, longer first and second stage of labour, oxytocin augmentation, epidural analgesia, instrumental vaginal delivery, chorion-amniositis, vaginal perineal injures, loss of blood and post partum infections. A highest incidence of occipito-posterior fetal head position may depend by nulliparity, malnutrition with pelvic deformity, pelvic immaturity in the teenager and anterior placenta. Epidural analgesia is a risk factor for fetal head malposition. The majority of occipito-posterior fetal head positions is not due to a malrotation, but to a persistence in this position of the fetal head. In fact, this persistence leads to a failure of the fetal head rotation. The prolonged second stage is often the result of occipito-posterior fetal head position and instrumental delivery is required. The traditional vaginal examination is not useful for the determination of fetal head position, so and instrumental method is needed, such as ultrasound, for a correct evaluation of fetal head position, particularly if a vaginal instrumental delivery is necessary. This is recommended by the Canadian Society of Obstetrics and Gynecology. The evaluation of fetal head position is important in the prediction of labour induction.
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PMID:[Occipito-posterior fetal head position, maternal and neonatal outcome]. 1792 36

Dopamine plays an important role in the pathogenesis of hypertension by regulating epithelial sodium transport and by interacting with vasoactive hormones/humoral factors, such as aldosterone, angiotensin, catecholamines, endothelin, oxytocin, prolactin pro-opiomelancortin, reactive oxygen species, renin, and vasopressin. Dopamine receptors are classified into D(1)-like (D(1) and D(5)) and D(2)-like (D(2), D(3), and D(4)) subtypes based on their structure and pharmacology. In recent years, mice deficient in one or more of the five dopamine receptor subtypes have been generated, leading to a better understanding of the physiological role of each of the dopamine receptor subtypes. This review summarizes the results from studies of various dopamine receptor mutant mice on the role of individual dopamine receptor subtypes and their interactions with other G protein-coupled receptors in the regulation of blood pressure.
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PMID:Dysregulation of dopamine-dependent mechanisms as a determinant of hypertension: studies in dopamine receptor knockout mice. 1808

A 28-year-old woman was admitted because of pregnancy induced hypertension at 35 weeks of gestation with twin babies. The premature labor had been inhibited for 2 weeks with ritodrine (100 microg min(-1) continuous infusion). At 37 weeks of gestation, an emergency cesarean section was carried out under combined spinal epidural anesthesia. After the delivery, oxytocin 5 units was injected to the uterine muscle and methylergometrin 0.2 mg was given intravenously to induce uterine contraction. One hour after the operation, she developed severe pulmonary edema. An echocardiography showed diffuse hypokinesis of the left ventricle with ejection fraction of 23%. She was diagnosed as having peripartum cardiomyopathy by cardiologist. The patient's condition improved in a few days but the abnormal cardiac function continued for two months.
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PMID:[Case of peripartum cardiomyopathy developed after an emergency cesarean section--a case report]. 1827 75

Oxytocinergic brainstem projections participate in the autonomic control of the circulation. We investigated the effects of hypertension and training on cardiovascular parameters after oxytocin (OT) receptor blockade within the nucleus tractus solitarii (NTS) and NTS OT and OT receptor expression. Male spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats were trained (55% of maximal exercise capacity) or kept sedentary for 3 months and chronically instrumented (NTS and arterial cannulae). Mean arterial blood pressure (MAP) and heart rate (HR) were measured at rest and during an acute bout of exercise after NTS pretreatment with vehicle or OT antagonist (20 pmol of OT antagonist (200 nl of vehicle)(-1)). Oxytocin and OT receptor were quantified ((35)S-oligonucleotide probes, in situ hybridization) in other groups of rats. The SHR exhibited high MAP and HR (P < 0.05). Exercise training improved treadmill performance and reduced basal HR (on average 11%) in both groups, but did not change basal MAP. Blockade of NTS OT receptor increased exercise tachycardia only in trained groups, with a larger effect on trained WKY rats (+31 +/- 9 versus +12 +/- 3 beats min(1) in the trained SHR). Hypertension specifically reduced NTS OT receptor mRNA density (-46% versus sedentary WKY rats, P < 0.05); training did not change OT receptor density, but significantly increased OT mRNA expression (+2.5-fold in trained WKY rats and +15% in trained SHR). Concurrent hypertension- and training-induced plastic (peptide/receptor changes) and functional adjustments (HR changes) of oxytocinergic control support both the elevated basal HR in the SHR group and the slowing of the heart rate (rest and exercise) observed in trained WKY rats and SHR.
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PMID:Brainstem oxytocinergic modulation of heart rate control in rats: effects of hypertension and exercise training. 1963 62

An imbalance of excitatory and inhibitory functions has been shown to contribute to numerous pathological disorders. Accumulating evidence supports the idea that a change in hypothalamic gamma-aminobutyric acid (GABA)-ergic inhibitory and glutamatergic excitatory synaptic functions contributes to exacerbated neurohumoral drive in prevalent cardiovascular disorders, including hypertension. However, the precise underlying mechanisms and neuronal substrates are still not fully elucidated. In the present study, we combined quantitative immunohistochemistry with neuronal tract tracing to determine whether plastic remodeling of afferent GABAergic and glutamatergic inputs into identified RVLM-projecting neurons of the hypothalamic paraventricular nucleus (PVN-RVLM) contributes to an imbalanced excitatory/inhibitory function in renovascular hypertensive rats (RVH). Our results indicate that both GABAergic and glutamatergic innervation densities increased in oxytocin-positive, PVN-RVLM (OT-PVN-RVLM) neurons in RVH rats. Despite this concomitant increase, time-dependent and compartment-specific differences in the reorganization of these inputs resulted in an altered balance of excitatory/inhibitory inputs in somatic and dendritic compartments. A net predominance of excitatory over inhibitory inputs was found in OT-PVN-RVLM proximal dendrites. Our results indicate that, along with previously described changes in neurotransmitter release probability and postsynaptic receptor function, remodeling of GABAergic and glutamatergic afferent inputs contributes as an underlying mechanism to the altered excitatory/inhibitory balance in the PVN of hypertensive rats.
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PMID:Altered balance of gamma-aminobutyric acidergic and glutamatergic afferent inputs in rostral ventrolateral medulla-projecting neurons in the paraventricular nucleus of the hypothalamus of renovascular hypertensive rats. 2003 60

To understand the incidence and causes of still-births occurred in Mymensingh Medical College Hospital, we conducted a retrospective record review study in Department of Gynaecology of the hospital. The study population were the cases of still births occurred the months of January and December 2007. We administered a structured questionnaire to all the Medical Officers working in the department. They were requested to provide information on the still-births they noticed during the study period. They review their personal log books and hospital records to complete the questionnaire. We also reviewed the hospital records to obtain the service statistics. In total 11,146 patients were admitted to seek obstetric care during the study period and of them 7,069(63%) sought delivery care. During this period there were 735(10%) still births. The incidences of still births were more during December and January. The pre-existing maternal diseases that were frequently associated with still births were Antepartum Haemorrhage (APH) 38% and hypertension (27%). The frequently reported direct causes of the still births were obstructed labour (42%), misuse of oxytocin (28%) and foetal distress (20%). In many cases the loss is completely unexpected. Hospital based surveillance and issuing of still-birth certificates may increase the awareness of the problem among the obstetricians and in the community.
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PMID:Understanding the magnitude of still birth in Mymensingh Medical College Hospital. 2063 23

An increasing amount of evidence demonstrates the beneficial role of oxytocin (OT) in the cardiovascular system. Similar actions are attributed to genistein, an isoflavonic phytoestrogen. The treatment with genistein activates the OT system in the aorta of ovariectomized (OVX) Sprague-Dawley (SD) rats. The objective of this study was to determine the effects of low doses of genistein on the OT-induced effects in rat hypertension. The hypothesis tested was that treatment of OVX spontaneously hypertensive rats (SHRs) with genistein improves heart structure and heart work through a mechanism involving the specific OT receptor (OTR). OVX SHRs or SD rats were treated with genistein (in microg/g body wt sc, 10 days) in the presence or absence of an OT antagonist (OTA) [d(CH(2))(5), Tyr(Me)(2), Orn(8)]-vasotocin or a nonspecific estrogen receptor antagonist (ICI-182780). Vehicle-treated OVX rats served as controls. RT-PCR and Western blot analysis demonstrated that left ventricular (LV) OTR, downregulated by ovariectomy, increased in response to genistein. In SHRs or SD rats, this effect was blocked by OTA or ICI-182780 administration. The OTR was mainly localized in microvessels expressing the CD31 marker and colocalized with endothelial nitric oxide synthase. In SHRs, the genistein-stimulated OTR increases were associated with improved fractional shortening, decreased blood pressure (12 mmHg), decreased heart weight-to-body weight ratio, decreased fibrosis, and lowered brain natriuretic peptide in the LV. The prominent finding of the study is the detrimental effect of OTA treatment on the LV of SHRs. OTA treatment of OVX SHRs resulted in a dramatic worsening of ejection fractions and an augmented fibrosis. In conclusion, these results demonstrate that cardiac OTRs are involved in the regulation of cardiac function of OVX SHRs. The decreases of OTRs may contribute to cardiac pathology following menopause.
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PMID:Cardiac oxytocin receptor blockade stimulates adverse cardiac remodeling in ovariectomized spontaneously hypertensive rats. 2067 Dec 91


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