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)

The effects of streptozotocin-induced diabetes mellitus on the activity of discrete regions of the brain were studied with histochemical localization and photodensitometric quantification of the metabolic enzyme, hexokinase. Two weeks after a single injection of streptozotocin (65 mg/kg, i.p.), plasma glucose and osmolarity levels were elevated, and plasma sodium concentrations were depressed. These changes were reversed in diabetic rats treated with insulin. Accompanying these symptoms of diabetes were significant increases in hexokinase activity in the magnocellular division of the paraventricular nucleus of the hypothalamus (mPVH, 12.1%), the medial subdivision of the nucleus of the tractus solitarius (mNTS, 15.5%), and the commissural subdivision of the NTS (cNTS, 10.9%). An increase, though just below the level of significance, was also observed in the supraoptic nucleus of the hypothalamus (SON, 11.5%). The increases in hexokinase activity were completely reversed in the cNTS (and SON) and only partly reversed in the mPVH and mNTS of insulin-treated diabetic rats. No changes in hexokinase activity were seen in the subfornical organ, medial preoptic area, parvocellular division of the PVH, locus coeruleus, or dorsal motor nucleus of the vagus of diabetic rats. These results reinforce the idea that the brain is not exempt from changes associated with diabetes mellitus and suggest that metabolic alterations in the mPVH (and SON) and two divisions of the NTS are likely related to changes in vasopressin production and blood volume, respectively.
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PMID:Alterations in brain hexokinase activity associated with streptozotocin-induced diabetes mellitus in the rat. 222 10

The precise role of hypothalamic norepinephrine (NE) in the control of vasopressin (AVP) release has remained unclear, due to reports of both inhibitory and excitatory effects of NE and only a few studies with direct hypothalamic manipulations. The present study utilized a chronically implanted swivel brain cannula to investigate, in undisturbed and freely behaving rats, the impact of acute hypothalamic infusions of monoamines on circulating AVP levels. The first study examined and compared the responsiveness of six hypothalamic sites to NE infusion through the swivel cannula. Results indicated that the excitatory effect of central noradrenergic stimulation on serum AVP is highly site specific, localized to the paraventricular (PVN) and supraoptic (SON) nuclei. These two nuclei appeared to be equally responsive to NE infusion, yielding a threefold rise in serum AVP over baseline levels. In contrast, NE in the dorsomedial nucleus produced a significantly smaller increase in AVP, and no response was observed in the ventromedial nucleus, posterior hypothalamus, or perifornical lateral hypothalamus. Further tests conducted in the PVN showed this nucleus to respond in a dose-dependent manner to NE infusion. In contrast, under similar test conditions, dopamine caused only a small increase in AVP at a relatively high dose, while a PVN injection of serotonin produced no response. These results support the existence of an excitatory noradrenergic system controlling AVP release and specifically demonstrate that this function of NE is localized to the PVN and SON, in contrast to other hypothalamic areas, and is mimicked to some extent by dopamine but not by serotonin.
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PMID:Mapping study of noradrenergic stimulation of vasopressin release. 224 40

Axon collaterals emerging from the vasopressinergic neurons of the supraoptic (SON) and paraventricular (PVN) nuclei and recurving back towards their respective nuclei have been previously reported. Since such axon collaterals can play a role in the neuromodulation of SON and PVN, these nuclei have been further investigated immunohistochemically under the light and electron microscope. The PAP technique, using a commercial antibody, was employed. Vasopressin-positive axon collaterals were seen to recurve towards their nuclei of origin. In the latter, vasopressinergic intrinsic neurons were also observed. Under the electron microscope, axon terminals containing vasopressin-immunoreactive neurosecretory granules were noted. Such terminals presumably arise from the vasopressin-positive recurrent axon collaterals or from the intrinsic neurons for the purpose of neuromodulation within the SON and PVN.
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PMID:Vasopressinergic axon collaterals and axon terminals in the magnocellular neurosecretory nuclei of the rat hypothalamus. 230 28

In the literature, activation of the hypothalamo-neurohypophyseal system (HNS) in normal aging has been demonstrated in rat and human. This activation might be secondary to an age-related decline in vasopressin binding sites in the kidney, or to cell loss in the supraoptic (SON) and paraventricular nuclei (PVN) and/or to an age-related decline in noradrenergic (NA) innervation of the hypothalamus. This study shows neuronal hypertrophy in SON and PVN in normal aging and an additional hypertrophy in Alzheimer's disease. No cell loss could be demonstrated in both conditions.
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PMID:Neuronal hypertrophy in the human supraoptic and paraventricular nucleus in aging and Alzheimer's disease. 231 42

Despite convincing physiological evidences for vasopressin (VP) autoregulation in the supraoptic (SON) and paraventricular (PVN) nuclei, the morphological demonstration of VP synapses has lagged behind. The present work investigates the possible existence of such synapses in the SON and PVN of the rat. Electron microscopy of sections immunostained with VP antibody (1:5,000) and conjugated with avidin-biotin demonstrated presynaptic terminals containing neurosecretory granule (NSG)-like bodies, 80-100 nm in diameter. The terminals formed axodendritic, axosomatic and axoaxonic synapses, though the postsynaptic elements remained largely unidentified. Other ultrastructural features of synaptic specialization were evident. The NSG-like bodies exhibited a varying and dynamic relationship to the presynaptic membrane, suggesting their involvement in synaptic mechanisms.
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PMID:Ultrastructural features of presumptive vasopressinergic synapses in the hypothalamic magnocellular secretory nuclei of the rat. 234 70

Isolated rat paraventricular (PVN) and supraoptic (SON) nuclei were perifused in vitro and oxytocin and vasopressin releases were measured by radioimmunoassay during rest and during electrical stimulation. Stimulations at a frequency of 10 Hz (10-s bursts, every 10 s for 5 min) and an intensity of 4 mA, induced significant hormone release only with long duration pulses (10 ms). Short pulses (1 ms) applied at various frequencies (10, 20, 40 or 80 Hz) and intensities (4, 5, 10 or 20 mA) had no effect. The electrically evoked release of both hormones was not affected by tetrodotoxin (TTX), a sodium channel blocker, but was blocked in low-calcium medium or in the presence of gallopamil hydrochloride (D-600), a calcium channel blocker. These results suggest that, following electrical stimulation, oxytocin and vasopressin are released locally within the magnocellular nuclei even when blocking action potentials. The possibility of dendritic release is discussed.
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PMID:Electrical stimulations of perifused magnocellular nuclei in vitro elicit Ca2+-dependent, tetrodotoxin-insensitive release of oxytocin and vasopressin. 243 5

Galanin is a peptide containing 29 amino acid residues, that is present in the median eminence, in the magnocellular neurons of the supraoptic (SON) and paraventricular nuclei (PVN) of the rat hypothalamus and in the posterior pituitary. We report here that: (1) immunoreactivity for galanin (GAL) and vasopressin coexist in the SON of normal rats, (2) levels of mRNA encoding preprogalanin are markedly elevated in the PVN and SON of Brattleboro (diabetes insipidus) rats, as determined by in situ hybridization histochemistry but (3) levels of GAL-like immunoreactivity (GAL-LI) are significantly reduced in the posterior pituitary of these rats, as determined by radioimmunoassay. We suggest that production and possibly secretion of the peptide GAL may be increased in the Brattleboro rat.
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PMID:Galanin coexists with vasopressin in the normal rat hypothalamus and galanin's synthesis is increased in the Brattleboro (diabetes insipidus) rat. 245 56

In summary, these anatomical and electrophysiological data have provided evidence to support the suggestion that VLM neurons project directly to regions of the hypothalamus that contain magnocellular neurosecretory neurons. In addition, these results support the suggestion that pathways ascending from the VLM to the hypothalamus function, in part, in the control of the release of the neurohypophyseal hormones by PVH and SON magnocellular neurosecretory neurons during activation of peripheral cardiovascular receptors.
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PMID:Organization of ventrolateral medullary afferents to the hypothalamus. 261 87

Microinjection of the muscarinic agonist oxotremorine into the hypothalamic supraoptic (SON) and paraventricular (PVN) nuclei which contain cell bodies of vasopressinergic neurons induced potent antidiuretic effects in water-loaded and ethanol-anesthetized rats. The effects included both decreases in urine outflow and increases in urine osmotic pressure. However, no significant changes in various visceral functions other than antidiuresis such as mean blood pressure, heart rate, respiration rate and rectal temperature were observed when oxotremorine was microinjected into the SON. Only a slight change in mean blood pressure (approx. 10 mmHg decrease) was observed by the microinjection into the PVN. Intravenous preinjection of a vasopressin (AVP) V1 V2 antagonist that has one of the most potent V2 (antidiuretic)-antagonist activities, d(CH2)5-D-Tyr(Et)VAVP, inhibited nearly completely the antidiuretic effects induced by the microinjection of oxotremorine. The results demonstrated that oxotremorine stimulated muscarinic receptors in the hypothalamic SON and PVN, released AVP and induced an antidiuretic effect through AVP-receptors in the kidney.
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PMID:Effect of vasopressin antagonist on antidiuresis by oxotremorine microinjected into the hypothalamic supraoptic and paraventricular nuclei in a water-loaded and ethanol-anesthetized rat. 274 38

The distribution, morphological features, and morphometric characteristics of cell bodies producing oxytocin (OT) and vasopressin (AVP) were studied in the rabbit hypothalamus by means of a conventional immunoperoxidase method. The aim of the present study was to determine the existence or not of a species-specific OT-cell group that might be involved in the dense OT innervation of the intermediate lobe in the leporidae. No OT-cell group clearly distinct from the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei was found, even in colchicine-treated animals. Most immunoreactive perikarya were found within these nuclei. In addition, small AVP neurons occurred in the suprachiasmatic nucleus. In the SON, the predominant, tightly packed AVP cells occupied the ventral part of the nucleus, whereas OT neurons were dorsolaterally located. The PVN presented a loose organization without any obvious subdivision. OT cells, which predominated, occupied the medial part of the nucleus. The PVN had a prominent rostral anterobasal extension composed mainly of OT cells. Laterally to the nucleus, numerous large AVP neurons, with few and smaller OT cells, dispersed along the neurosecretory tract without forming definite cell clusters. AVP cell bodies had a rough granular aspect contrasting with the smooth and fine one of OT cells. Spinelike processes were rarely observed on the perikarya, except on large scattered AVP neurons, but frequently covered the proximal dendrites of both types of neurons. Throughout the hypothalamus, OT neurons had definitely smaller mean somal areas and were more homogeneous in size than AVP cells.
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PMID:Distribution and morphometric characteristics of oxytocin- and vasopressin-immunoreactive neurons in the rabbit hypothalamus. 276 Feb 67


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