Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Endogenous opioid peptides are present in cerebral perivascular nerves and in the CSF, and their concentrations are changing in response to stimuli that activate regulatory mechanisms of the cerebral circulation (e.g., alterations of the perfusion pressure or changes of the arterial O2 tension). Opiate receptors are expressed in the cells of the CNS and the cerebrovascular bed, and their activation modulates the function of other vasoregulatory mechanisms (i.e., the autonomic nervous system, nitric oxide, prostanoids, vasopressin) that are involved in the control of the cerebrovascular tone. The direct vasomotor effects of opioid peptides and opiates on the cerebral arteries under in vitro or in situ conditions appear to be weak or absent in several species. However, Met- and Leu-enkephalin induce pial arterial vasodilation in the newborn pig. In this species, beta-endorphin acts as a constrictor, whereas dynorphin may induce either dilation or constriction depending on the experimental conditions. The influence of exogenously applied natural and synthetic opioids on the cerebral blood flow (CBF) is determined mainly by their metabolic, neuronal, and respiratory effects. Hypothalamic and pituitary circulations are especially sensitive to opioids. Under resting conditions, endogenous opioid peptides do not participate in the regulation of the cerebrovascular tone and CBF. On the other hand, mu and delta opiate receptor stimulation by endogenous opioid peptides, interacting with other vasoactive factors, obviously contributes to the hypoxia- and hypercapnia-induced cerebral vasodilation. Furthermore, endogenous opioid mechanisms are involved in the autoregulation of the hypothalamic blood flow. Thus, the endogenous opioid system may well represent a latent regulatory mechanism, which is of limited importance under basal conditions, but becomes more important under conditions of stress. Synthetic exogenous opioids do not appear to influence the hypoxic or hypercapnic CBF responses or the cerebral autoregulatory process.
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PMID:Opiate receptor-mediated mechanisms in the regulation of cerebral blood flow. 896 68

To clarify the role of neurones in the anteroventral third ventricle (AV3V) area in cardiovascular responses to CSF sodium, ouabain and angiotensin II (ANG II), we employed excitotoxic lesions of the ventral AV3V (vAV3V). In conscious lesioned Wistar rats with systemic vasopressin blockade, pressor and tachycardiac responses to intracerebroventricular (i.c.v.) artificial CSF containing 0.3 M NaCl or ouabain were significantly attenuated by 26-32% whereas responses to ANG II were not affected. Thus, in rats with systemic blockade of vasopressin mechanisms, the vAV3V region partially mediates acute pressor responses to i.c.v. sodium and ouabain but not to ANG II.
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PMID:Excitotoxic lesions of the ventral anteroventral third ventricle and pressor responses to central sodium, ouabain and angiotensin II. 907 Jun 43

The physicochemical properties of water enable it to act as a solvent for electrolytes, and to influence the molecular configuration and hence the function--enzymatic in particular--of polypeptide chains in biological systems. The association of water with electrolytes determines the osmotic regulation of cell volume and allows the establishment of the transmembrane ion concentration gradients that underlie nerve excitation and impulse conduction. Fluid in the central nervous system is distributed in the intracellular and extracellular spaces (ICS, ECS) of the brain parenchyma, the cerebrospinal fluid, and the vascular compartment--the brain capillaries and small arteries and veins. Regulated exchange of fluid between these various compartments occurs at the blood-brain barrier (BBB), and at the ventricular ependyma and choroid plexus, and, on the brain surface, at the pia mater. The normal BBB is relatively permeable to water, but considerably less so to ions, including the principal electrolytes Brain fluid regulation takes place within the context of systemic fluid volume control, which depends on the mutual interaction of osmo-, volume-, and pressure-receptors in the hypothalamus, heart and kidney, hormones such as vasopressin, renin-angiotensin, aldosterone, atriopeptins, and digitalis-like immunoreactive substance, and their respective sites of action. Evidence for specific transport capabilities of the cerebral capillary endothelium, for example high Na+K(+)-ATPase activity and the presence at the abluminal surface of a Na(+)--H+ antiporter, suggests that cerebral microvessels play a more active part in brain volume regulation and ion homoeostasis than do capillaries in other vascular beds. The normal brain ECS amounts to 12-19% of brain volume, and is markedly reduced in anoxia, ischaemia, metabolic poisoning, spreading depression, and conventional procedures for histological fixation. The asymmetrical distributions of Na+ K+ and Ca2+ between ICS and ECS underlie the roles of these cations in nerve excitation and conduction, and in signal transduction. The relatively large volume of the CSF, and extensive diffusional exchange of many substances between brain ECS and CSF, augment the ion-homeostasing capacity of the ECS. The choroid plexus, in addition to secreting CSF principally by biochemical mechanisms (there is an additional small component from the extracellular fluid), actively transports some substances from the blood (e.g. nucleotides and ascorbic acid), and actively removes others from the CSF. In contrast with CSF secretion, CSF reabsorption is principally a biomechanical process, passively dependent on the CSF-dural sinus pressure gradient. Pathological increases in intracranial water content imply development of an intracranial mass lesion. The additional water may be distributed diffusely within the brain parenchyma as brain oedema, as a cyst, or as increase in ventricular volume due to hydrocephalus. Brain oedema is classified on the basis of pathophysiology into four categories, vasogenic, cytotoxic, osmotic and hydrostatic. The clinical conditions in which brain oedema presents the greatest problems are tumour, ischaemia, and head injury. Peritumoural oedema is predominantly vasogenic and related to BBB dysfunction. Ischaemic oedema is initially cytotoxic, with a shift of Na+ and CI- ions from ECS to ICS, followed by osmotically obliged water, this shift can be detected by diffusion-weighted MRI. Later in the evolution of an ischaemic lesion the oedema becomes vasogenic, with disruption of the BBB. Recent imaging studies in patients with head injury suggest that the development of traumatic brain oedema may follow a biphasic time course similar to that of ischaemic oedema. Hydrocephalus is associated in the great majority of cases with an obstruction to the circulation or drainage of CSF, or, occasionally, with overproduction of CSF by a choroid plexus papilloma. In either case, the consequence is a ris
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PMID:The normal and pathological physiology of brain water. 907 71

Stress or noxious stimuli of various kind may induce the fight-flight response. In this situation a number of physiological and behavioural adaptations leading to defense of the organism occur. At a central level increased activity in the noradrenergic locus coeruleus (LC) and an enhanced secretion of corticotrophin-releasing factor (CRF) and vasopressin produced in the paraventricular nucleus (PVN) integrate stress response. Here the existence of an opposite psycho-physiological pattern associated with relaxation and growth and which is activated by certain types of non-noxious stimuli and integrated by oxytocin is proposed. In support of this, administration of oxytocin to male and female rats gives rise to effects of antistress nature in particular after repeated administration. Thus a five day treatment period with oxytocin 1 mg/kg s.c. or 1 micro g/kg i.c.v gives rise to sedation, lowering of blood pressure, increased withdrawal latency in the tail flick test and also a decrease of corticosterone levels and a rise of certain vagally controlled hormones. Weight gain is also increased under certain conditions. These effects persist several weeks after administration of oxytocin and cannot be reversed by oxytocin antagonists when established, suggesting that secondary mechanisms have been activated. Naloxone temporarily reverses the increased withdrawal of the tail flick test suggesting that opioid mechanisms have been activated to cause this particular effect. In contrast the sedative and blood pressure lowering effect seems to be induced by an enhanced activity in central alpha 2 receptors. Oxytocin levels increase in blood and CSF after various kinds of non-noxious sensory stimulation such as touch, light pressure and warm temperature in both female and male rats. It is suggested that other types of non-noxious stimuli as well may increase oxytocin release. If so, a release of oxytocin could be responsible for not only the antistress effects occurring during lactation but also why relationships, social contact and networks may have health promoting effects in particular by preventing cardiovascular disease.
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PMID:Oxytocin linked antistress effects--the relaxation and growth response. 940 3

von Willebrand's disease (VWD) is the most common hereditary bleeding disorder. Unchecked or improperly managed, VWD-associated hemorrhage can lead to catastrophic surgical outcome. Based on the authors' recent experience with 21 procedures in 12 patients, a contemporary protocol for successful perioperative management of VWD in otolaryngologic surgery is presented. In patients with VWD type 1 or 2a, desmopressin, a synthetic vasopressin analog, is administered both pre- and postoperatively to release von Willebrand factor (VWF) from storage sites. In type 2b or 3, a factor VIII concentrate rich in VWF is administered. In addition, a 10- to 14-day course of intravenous and/or oral Amicar (Immunex Corp., Seattle, WA) may be prescribed postoperatively. Intraoperatively, the surgical laser is used to further decrease blood loss and augment hemostasis. This medical and surgical protocol minimizes the risk of hemorrhage and of transfusion-related complications through the judicious use of preoperative and postoperative coagulation replacement products. Using these guidelines in a variety of otolaryngologic cases, the authors have had no bleeding complications at their institution.
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PMID:Perioperative management of von Willebrand's disease in otolaryngologic surgery. 943 63

1. In this study, we investigated the effects of different drugs (a kappa-opioid receptor agonist U-50,488, a vasopressin receptor antagonist dPTyr(Me)AVP or an N-methyl-D-aspartate (NMDA) receptor antagonist MK-801) on the development of morphine tolerance in rat hippocampal slices. 2. Hippocampal slices (450 microm) of Sprague-Dawley rats (250-300 g) were used. Slices were continuously superfused with artificial CSF or drugs at 1 ml min(-1). Nichrome wire electrodes were placed in the Schaffer-collateral pathway and used to deliver biphasic 0.2 ms pulses of 5-30 V (0.033 Hz). A glass microelectrode was placed in the CA1 area to record population spikes. 3. When the slices were superfused with 10 microM morphine, the amplitude of population spikes increased 2-3 fold in 30-40 min. However, this effect of morphine decreased, i.e. tolerance developed after continuous superfusion of morphine for 2-6 h. 4. When either U-50,488 (200 nM) or dPTyr(Me) AVP (500 pM) or MK-801 (500 pM) was co-superfused with morphine (10 microM), it significantly blocked the development of morphine tolerance. Nor-BNI (a kappa-opioid receptor antagonist, 200 nM) significantly reversed the inhibitory effect of U-50,488 but not those of dPTyr(Me)AVP or MK-801 on the development of morphine tolerance. 5. These data indicate that kappa-opioid receptors, AVP receptors and NMDA receptors are all involved in the development of morphine tolerance. The suppression of kappa-opioid receptor activity after chronic morphine may occur before the activation of AVP receptors or NMDA receptors during the development of morphine tolerance.
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PMID:Blockade of the development of morphine tolerance by U-50,488, an AVP antagonist or MK-801 in the rat hippocampal slice. 951 80

Paraneoplastic limbic encephalitis (PLE) is a manifestation of clinico pathological entity encephalo-myelo-neuropathy associated with anti-neuronal antibodies type 1 (ANNA-1 also called anti-Hu). Isolated PLE is rare. We reported a case of PLE in a 61-year-old heavy smoker man. An inappropriate antidiuretic hormone secretion syndrome was associated. Cranial MRI showed hyperintensity in amygdalo-hippocampic regions on T2 weighted sequences which appeared hypointense on T1-weighted sequences without gadolinium enhancement. Anti-Hu antibodies were absent in serum and in CSF. Despite chemotherapy, he died 18 months after disease onset. Our patient presented PLE without myelonouropathy and without ANNA-1 which suggests a different immunopathology.
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PMID:[Limbic encephalitis and SIADH revealing small-cell anaplastic lung cancer: MRI and immunologic findings]. 977 88

A 68 year old woman with sporadic Creutzfeldt-Jakob disease is described, who neither showed characteristic EEG abnormalities nor a positive test of the neuronal protein 14-3-3 or neuron specific enolase (NSE) in CSF, despite a clinical presentation with ataxia of cerebellar type, rapidly progressive dementia, myoclonus, and marked hyperintense signal abnormalities in the deep cortical layers and the basal ganglia on T2 and diffusion weighted MRI. Moreover she showed atypical clinical features with a syndrome of inappropriate antidiuretic hormone (ADH) secretion (SIADH) and a peripheral sensorimotor polyneuropathy. Whether these disturbances are independent of Creutzfeldt-Jakob disease or a feature of it is discussed. It has recently been shown that in Creutzfeldt-Jakob disease different clinical and pathological phenotypes correlate with the polymorphism at codon 129 of the prion protein gene (PRNP) and the type of the protease resistant fragment that accumulates in the brain. According to the new classification at least six sporadic variants of Creutzfeldt-Jakob disease exist. The molecular genetic analysis showed heterozygosity of PRNP at codon 129 for methionine and valine and the presence of PrP(CJD) type 2 in the brain of this patient. As a new feature of changes on MRI, striking cortical changes of hyperintense signals are described in diffusion weighted as well as T2 weighted MRI that directly correlate with the histomorphological spongy degeneration of the brain in this region. In cases of rapidly progressive dementia, Creutzfeldt-Jakob disease always needs to be considered even if unusual features are present and current diagnostic criteria are not in favour of this disease.
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PMID:Clinical range and MRI in Creutzfeldt-Jakob disease with heterozygosity at codon 129 and prion protein type 2. 1051 81

Since neurohypophyseal germinomas occur at the pituitary and hypothalamic axis in children and adolescents, the endocrinopathy is one of the common and critical QOL determinants. We carried out a retrospective study on the outcome of endocrine function in patients with neurohypophyseal germinoma, in order to improve or preserve pituitary function after treatment. Sixteen patients (7 men and 9 women), aged 6 to 26 years were admitted and followed up for 95.3 (14-197) months. DI was noted in 12 patients in pretreatment and 16 in posttreatment regardless of tumor size. We carried out the replacement of GH in all 8 patients, presenting the symptoms under 15 years of age. Gonadal or gonadotropic, thyroid and adrenal hormones were replaced in 9, 12 and 15 patients, respectively. Patients with large tumor compressing chiasm or hypothalamus needed hormonal replacement such as gonadal or gonadotropic and thyroid hormones more frequently (<0.01) than those with small one. In addition, two patients with a small tumor at the pituitary stalk and the 3rd ventricle floor showed the improvement of secretion pattern in gonadotropins and ACTH after chemotherapy, although they later needed radiation therapy to control the tumor. Based on our study and review of literature, the endocrinological studies before and after treatment demonstrated that pituitary dysfunction present before treatment persisted or worsened even after tumor remission, except for patients with small and localized ones. The poor endocrine results is considered to be largely radiation-related. Chemotherapy alone seems to be insufficient to obtain complete response (CR). To avoid radiation related pituitary injury, combination of 24 Gy or less dosage of radiation and appropriate chemotherapy is essential. The earlier diagnosis by repeatedly using neuroimaging and serum and CSF tumor markers and earlier initiation of treatment, before irreversible pituitary-hypothalamic damage occurs, contributes to improvement of the outcome of pituitary functions in patients with neurohypophyseal germinomas.
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PMID:Long-term outcome of endocrine function in patients with neurohypophyseal germinomas. 1081 Dec 97

This study was designed to characterize the role of vasopressin in impaired pial artery dilation to activators of the ATP sensitive K (K(ATP)) and calcium sensitive K (K(ca)) channel following fluid percussion brain injury (FPI) in newborn pigs equipped with a closed cranial window. Topical vasopressin was coadministered with the K(ATP) and K(ca) channel agonists cromakalim and NS1619 in a concentration approximating that observed in CSF following FPI. Vasopressin so administered attenuated pial artery dilation to these K(+) channel activators under conditions of equivalent baseline diameter during non injury conditions (13+/-1 and 23+/-1 vs. 4+/-1 and 10+/-2% for cromakalim 10(-8), 10(-6) M before and after vasopressin, respectively). Attenuated responses were fully restored when these agonists were coadministered with vasopressin and the vasopressin antagonist [l-(beta-mercapto-beta, beta-cyclopentamethylene propionic acid) 2-(o-methyl)-Tyr-AVP] (MEAVP). Cromakalim and NS1619 induced pial artery dilation was attenuated following FPI and MEAVP preadministration partially prevented such impairment (13+/-1 and 23+/-1, sham control; 2+/-1 and 5+/-1, FPI; and 9+/-1 and 15+/-2%, FPI-MEAVP pretreated for responses to cromakalim 10(-8), 10(-6) M, respectively). These data show that vasopressin blunts K(ATP) and K(ca) channel mediated cerebrovasodilation. These data suggest that vasopressin contributes to impaired K(ATP) and K(ca) channel function after brain injury.
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PMID:Vasopressin impairs K(ATP) and K(ca) channel function after brain injury. 1113 31


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