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Query: UNIPROT:P01185 (vasopressin)
 23,126 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Arginine vasopressin (AVP) is a potent neuroactive and vasoactive nonapeptide encoded in and processed from a precursor, preproarginine vasopressin-neuro-physin II (preproAVP-NPII). To study the physiologic consequences of a genetic model of chronic hypervasopressinemia transgenic mice were produced by introduction of a mouse metallothionein-rat-ppAVP-NPII fusion gene into the germ line of mice. Three stable transgenic pedigrees were analyzed through several generations. Levels of immunoreactive AVP and neurophysin (NP) in sera, livers, kidneys, intestines, pancreas, and brains were markedly elevated. Chromatographic analyses showed sera levels of approximately 500 pg/ml (normal 0-20 pg/ml) of authentic AVP non-apeptide and serum osmolalities were elevated, 315.4 +/- 1.4 mosm/liter (control, 307.3 +/- 1.1), consistent with a state of mild nephrogenic diabetes insipidus. Brain levels of immunoreactive AVP in transgenic mice were 3-4-fold elevated 145 +/- 15 ng/g versus 31 +/- 7 (controls). Although immunoreactive AVP in livers and intestines, and to some extent kidneys, consisted predominantly of unprocessed precursors, in brain and pancreas greater than 90% of AVP consisted of processed bioactive nonapeptide, as determined by chromatography and measurements of cAMP-generation in LLC-PK1 cells. Immunocytochemistry localized immunoreactive AVP to the exocrine pancreas and to the magnacellular neurons (SON and PVN) of the hypothalamus. Expression of the fusion gene in the hypothalamus was further demonstrated by Northern analyses of fusion gene specific transcripts and in situ histohybridization. Although the fusion gene contained only 35 base pairs of 5'-flanking DNA of the ppAVP-NPII gene, a tentative neuronal cell-specific expression element, -17GCCCAG-CC-10 resides in this sequence and may confer neuron-specific expression to the fusion gene.
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PMID:Metallothionein-vasopressin fusion gene expression in transgenic mice. Nephrogenic diabetes insipidus and brain transcripts localized to magnocellular neurons. 280 95

Monosodium-L-glutamate (MSG) lesioning of the arcuate nucleus (ARC) was utilized to elucidate the importance of its dopaminergic system for regulation of neurohypophyseal vasopressin (AVP) secretion. Water deprivation in control animals elicited a rise in plasma AVP and depletion of neurohypophyseal AVP, at unchanged AVP contents of the paraventricular (PVN) and supraoptic (SON) nuclei. Dopaminergic activity was markedly stimulated in the PVN and ARC. Neonatal MSG treatment resulted in elevated plasma AVP levels at reduced neurohypophyseal AVP due to diminished dopaminergic input from the ARC. When MSG treated animals were subjected to dehydration, none of the changes in plasma/neurohypophyseal AVP and dopamine metabolism in the PVN and ARC observed in control animals were seen. These results suggest that the ARC plays an important role in the dopaminergic control of neurohypophyseal AVP secretion.
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PMID:Impaired regulation of neurohypophyseal vasopressin secretion in rats treated neonatally with monosodium-L-glutamate. 282 65

The cardiovascular responses to selective alpha 1- and alpha 2-adrenoceptor antagonism (with prazosin and idazoxan, respectively) were assessed in rats 4 weeks after unilateral nephro-adrenalectomy, contralateral adrenal enucleation and the provision of a 1% NaCl solution as drinking fluid (AEN rats) and in sham-operated (SON) rats. Measurements were made between 0700 and 1000 h and between 1400 and 1700 h, since we have previously shown that resting blood pressures (BPs) in AEN rats are higher in the morning than in the afternoon. Following prazosin administration (morning or afternoon), BP fell to similar levels in both SON and AEN rats. Idazoxan, given 20 min after the start of prazosin infusion, caused similar transient falls in BP in all four groups of rats. Following the subsequent additional antagonism of angiotensin II (Ang II) production (with captopril) and vasopressin (V1) receptors [with d(CH2)5DAVP], BP in AEN rats studied in the morning was higher than in SON rats at that time of day, and higher than in AEN rats studied in the afternoon. These findings suggest than an additional underlying mechanism capable of increasing BP exists in AEN rats studied in the morning.
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PMID:The cardiovascular responses to sequential inhibition of alpha-adrenoceptors, the renin-angiotensin system and vasopressin in rats with adrenal regeneration hypertension. 289 90

The objective of this study was to determine whether chronic arterial baroreceptor deficit induces time-related changes in central vasopressin (AVP) and catecholamine systems. Groups of sinoaortic-denervated (SAD) and sham-operated (SO) rats were studied 1, 3, 4, 7, and 14 days after surgery. Supraoptic (SON), paraventricular (PVN) and arcuate (ARC) nuclei, median eminence (ME) region, and A1 region of medulla were obtained by micropunch from frozen brain sections and assayed for AVP, tyrosine hydroxylase (TH) activity, catecholamines, and their metabolites, dihydroxyphenylethyleneglycol (DOPEG) and 2,5-dihydroxyphenylacetic acid (DOPAC). AVP concentration in SON and PVN was increased in 1-day-SAD rats, reduced in 3- and 4-day-SAD rats, equal and above control values in 7- and 14-day-SAD rats, respectively. TH activity was increased in SON and reduced in ME and ARC of 1- and 7-day-SAD rats. In SON, DOPEG was increased, whereas in ME all catecholamines and DOPEG and DOPAC were reduced in 1-day-SAD rats. ME catecholamines returned toward control levels in 3- to 4-day-SAD rats. These studies show that the chronic absence of arterial baroreceptor input produces time-related, regionally specific central changes of vasopressin and regionally associated catecholamines.
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PMID:Effects of chronic sinoaortic denervation on central vasopressin and catecholamine systems. 290 84

The neurones in the supraoptic and paraventricular nuclei (SON and PVN) which secrete vasopressin are separate from those which secrete oxytocin and are distributed in different parts of the nuclei. They may be distinguished electrophysiologically by a characteristic phasic pattern of firing. A selective afferent neural input to these neurones would provide a mechanism for the release of vasopressin independently of oxytocin in response to appropriate physiological stimuli. Release of vasopressin is controlled by changes in blood volume or pressure ('volume control') and in plasma osmolality ('osmotic control'). Stimuli involved in volume control such as haemorrhage, hypotension and carotid occlusion cause vasopressin to be released into the circulation with little or no detectable oxytocin. An osmotic stimulus releases vasopressin alone in some species but not apparently in the rat in which both hormones are released. Volume control is mediated reflexly by peripheral receptors in the cardiovascular system. Activation of baro- and stretch receptors results in inhibition, and activation of chemoreceptors in stimulation, of release. Afferent impulses from these receptors are conveyed in the vagi and carotid sinus nerves to the NTS on the dorsal surface of the brain stem. All afferent impulses to the NTS are excitatory. It follows that the afferents from chemoreceptors must stimulate an excitatory, and those from baro- and stretch receptors an inhibitory, projection from the NTS to the vasopressin-secreting cells in the SON and PVN. Two alternative models are presented of the neural pathways and transmitters involved. The model of Fig. 2 shows an excitatory relay through a cholinoceptive area on the ventral surface of the brain stem which has been termed the 'nicotine-sensitive area' because topical application of nicotine to this area in the cat released vasopressin without oxytocin. An inhibitory relay is shown through the A1 group of noradrenergic neurones on the ventral surface which selectively innervate the vasopressin-secreting neurones in the SON. This model implies an inhibitory role for noradrenaline acting on beta- or alpha 2-receptors. However the most recent investigations suggest an excitatory, rather than inhibitory, function of the A1 noradrenergic neurones involving alpha 1-receptors. This is the basis of the model in Fig. 3. The A1 neurones project either directly to the SON and PVN or indirectly through the lateral preoptic nucleus which lies in close proximity to the SON. The nicotine-sensitive area may be coincident with the A1 group of noradrenergic neurones.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Control of release of vasopressin by neuroendocrine reflexes. 290 66

To investigate the central nervous system (CNS) changes in the spontaneously hypertensive rat (SHR), a tissue culture model was used to examine the content and release (24 hour) of the peptide hormones, vasopressin (VP) and oxytocin (OT), from brain explants. Nuclear regions consisting of the paraventricular (PVN) or supraoptic (SON) nuclei were microdissected from prehypertensive SHR and Wistar-Kyoto (WKY) rats. Media levels of VP and OT were measured at 1, 3, 4, and 7 days of culture. After three days of culture, the PVN explants from SHR secreted significantly less VP and OT (both reduced 80%) than did those from WKY. Release of both VP and OT in the SON explants was significantly lower (approximately 50% lower) in the SHR only at seven days of culture. Additionally, tissue content of the peptides was measured after 0, 1, 4, and 7 days of culture. Tissue content of VP and OT was decreased (40% or more) in the SHR in both nuclear regions after four and seven days of culture. In addition, nicotine was found to stimulate the release of VP from SON, but not PVN, cultures in both SHR and WKY explants. Immunohistochemical data showed that there was not a preferential loss of VP or OT neurons in explants from the SHR. Therefore, this in vitro model would indicate that there is a difference in the ability of cultured explants of PVN and SON from SHR and WKY (four-week-old) to synthesize and/or release the peptide hormones VP and OT.
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PMID:Cultured hypothalamic explants from spontaneously hypertensive rats have decreased vasopressin and oxytocin content and release. 291 84

Recently, there has been an explosion of knowledge on vasopressin, including its neuro-anatomy, biochemistry and physiology. Recent work demonstrates extensive extra-hypothalamic vasopressinergic projections from the SON and PVN. Of particular importance are projections to the cardiovascular medullary centres. Conversely, the SON and PVN receive reciprocal catecholaminergic innervation from autonomic medullary centres. Vasopressin should now be regarded as a peptide hormone with important peripheral effects, as well as a neuropeptide acting as a neurotransmitter or neuromodulator with important CNS actions. The central and peripheral vasopressin systems are not only anatomically differentiated, but, although integrated, may also function independently. There is an important interaction between the central vasopressin system and the autonomic nervous system. Vasopressin has multiple and diverse actions on the cardiovascular system, including direct vasoconstriction, antidiuresis and hence volume control, central actions on cardiovascular neural centres, modulation of the baroreflex and direct cardiac effects. It also acts in concert with the sympathetic nervous system and the renin-angiotensin system as an integrated neurohormonal system in the control of blood pressure. Vasopressin appears to have an important role as a vasoconstrictor agent whenever volume is threatened, such as in dehydration, haemorrhage, adrenal insufficiency and orthostasis. It seems unlikely that vasopressin acts as a direct vasoconstrictor agent in the pathogenesis of any form of experimental or human hypertension. Although plasma vasopressin levels have been reported to be elevated in most forms of hypertension, this correlates best with the severity of hypertension. Furthermore, the levels are not elevated to the pressor range, so that increased vascular reactivity and sensitivity has to invoked. This does not appear to be specific for vasopressin. However, vasopressin may be indirectly involved through volume maintenance or interactions within the CNS. Indeed, its volume retaining properties have probably been underestimated. Whereas in acute situations the vasoconstrictor properties may be of some importance, it is difficult to sustain long-term hypertension without maintenance of an adequate plasma volume. Vasopressin's central actions on the cardiovascular medullary centres, the baroreflex, the autonomic nervous system and catecholamine metabolism may also be involved in some hypertensive processes.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Vasopressin in circulatory control and hypertension. 293 70

The response of the SON to various forms of stress is well documented. However, the effect of operative stress, which is a common and important clinical event requiring the mediation of vasopressin, has largely escaped attention. The present report describes the ultrastructural changes in the neurons of the caudal (retrochiasmatic) part of the SON following a deepseated linear incision on the dorsum of the rat. The observations were confirmed to the first forty-eight hours after trauma. At 24-hours post-operatively, a marked depletion of the neurosecretory granules was observed. This was associated with a proliferation of the granular and smooth endoplasmic reticulum, Golgi cisternae and ribosomes. A few of the neurosecretory granules were seen to lie in the close vicinity of the Golgi complexes. At 48-hours after trauma, these features persisted. In addition, an accumulation of neurosecretory granules was conspicuous in some axon pre-terminals. From the above findings, it is suggested that an increased demand for vasopressin during the early postoperative period is met by the supraoptic neurons by a liberation of their neurosecretory contents. An attempt at replenishment of the latter is evidenced by a proliferation in the membrane components and ribosomes. The pooling of neurosecretory granules in occasional axon pre-terminals may indicate an imbalance in the synthesis-secretion coupling of vasopressin.
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PMID:Ultrastructural observation on the rat supraoptic neurons following acute operative stress. 298 Feb 20

Diurnal changes in the expression of the vasopressin (VP) and oxytocin (OT) genes in the supraoptic (SON), paraventricular (PVN) and suprachiasmatic nuclei (SCN) of the rat were investigated by dot-blot and in situ hybridization of the VP and OT mRNAs. A significant diurnal variation in VP mRNA level was measured in the SCN, with highest levels around 17.00 h and lowest levels around midnight. No variations in levels of VP mRNA and OT mRNA were detected in SON and PVN. The data indicate that the regulation of the VP gene in the SCN is independent of that in the magnocellular nuclei.
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PMID:Diurnal variation in vasopressin and oxytocin messenger RNAs in hypothalamic nuclei of the rat. 321 75

Experiments were done to provide a detailed map of the location and a description of morphological characteristics of vasopressin (AVP-IR)-, neurophysin II (NII-IR)- and oxytocin (OXY-IR)-immunoreactive neuronal perikarya in the forebrain of the cat. In addition, the location of cells in the forebrain retrogradely labeled following injections of tracers into the neurohypophysis was determined. The distribution of AVP-IR and NII-IR was similar in all cases studied. Most of the cells containing AVP-IR and OXY-IR were observed in the hypothalamic paraventricular (PVH) and supraoptic (SON) nuclei. In addition, AVP-IR and OXY-IR cell bodies were found in the regions of the nucleus of the diagonal band of Broca, the dorsal chiasmatic nucleus, the anterior hypothalamic-preoptic area, the periventricular area, the nucleus circularis, the perifornical area of the lateral hypothalamus, the accessory SON, the area of the tuber cinereum (Tca), and the medial nucleus of the amygdala. The density of AVP-IR cells was greater than that of OXY-IR cells in these regions. Several forebrain areas were also observed to contain only AVP-IR perikarya: the suprachiasmatic nucleus (Sc), the bed nucleus of the stria terminalis, and the region of the substantia innominata and ventral globus pallidus (SI/GP). In addition, the dorsomedial nucleus of the hypothalamus only contained OXY-IR perikarya. Most of the cells immunoreactive to AVP were multipolar and had spinelike processes over their somata and proximal dendrites. In addition, the majority of cells in the PVH and SON were round or oval, whereas those outside these nuclei were fusiform or triangular. The mean somal area of AVP-IR cells in the region of the SI/GP was significantly (P less than 0.05) larger than that of AVP-IR cells in all other regions examined, whereas the mean somal area of Sc AVP-IR cells was significantly (P less than 0.05) smaller than that of all other groups of AVP-IR cells examined. Most OXY-IR cells were similar morphologically to those immunoreactive to AVP, except that OXY-IR cell bodies and their appendages did not have spinelike processes. In addition, OXY-IR perikarya were generally of uniform size. OXY-IR cells in the PVH and accessory SON were significantly (P less than 0.05) larger than AVP-IR cells in the same regions, but were not different from AVP-IR cells in the lateral hypothalamus and SON.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Distribution and morphology of vasopressin-, neurophysin II-, and oxytocin-immunoreactive cell bodies in the forebrain of the cat. 329 31


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