Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01178 (oxytocin)
 15,767 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunoreactive-vasopressin, -oxytocin, -dynorphin, -dynorphin-(1-8), -alpha-neo-endorphin and -[Met]enkephalin were, in each case, present in greater concentrations in dorsal as compared to ventral, and lumbo-sacral as compared to cervico-thoracic, spinal cord. These differences were significantly more pronounced for vasopressin and oxytocin than for the other peptides. Lesions of the hypothalamic paraventricular nucleus depleted levels of immunoreactive-vasopressin and -oxytocin throughout the cord whereas levels of the opioid peptides therein were unaffected. In contrast, destruction of either the supraoptic or suprachiasmatic nucleus failed to change the content of immunoreactive-vasopressin, -oxytocin or any of the opioid peptides in the cord. Dehydration for 3 days depressed levels of immunoreactive-vasopressin, -oxytocin and -dynorphin in the neurointermediate lobe of the pituitary. In distinction, the levels of these were not modified in the spinal cord. Further, treatment with the synthetic corticosteroid, dexamethasone, elevated levels of immunoreactive-vasopressin, -oxytocin and -dynorphin in the neurointermediate pituitary whereas these were unaffected in the spinal cord. It is concluded that vasopressin and oxytocin in the spinal cord are predominantly derived from the paraventricular nucleus, localized in dorsal lumbo-sacral regions of the cord and insensitive to endocrinological manipulations. These pools may, thus, be modulated differently from their counterparts in the neurohypophysis and have a differing role, possibly in the control of the primary processing, autonomic or motor junctions. Further, there is no evidence from these or our prior studies for a close interrelationship of spinal cord vasopressin with dynorphin-related peptides (or oxytocin with [Met]enkephalin), likewise in contrast to the neurohypophysis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Vasopressin and oxytocin in the rat spinal cord: distribution and origins in comparison to [Met]enkephalin, dynorphin and related opioids and their irresponsiveness to stimuli modulating neurohypophyseal secretion. 614 93

The postnatal development of several pro-enkephalin-B-derived opioid peptides - dynorphin 1-17, dynorphin 1-8, dynorphin B, alpha-neo-endorphin and beta-neo-endorphin - was examined in rat pituitary lobes. The concentrations of pro-enkephalin-B-derived peptides from the anterior pituitary were between 4- and 12-fold and those from the neurointermediate pituitary between 17- and 122-fold lower in newborn as compared to adult rats. Similarly, the concentrations of vasopressin in the neurointermediate pituitary increased 50-fold between birth and adulthood; those of oxytocin, however, increased more than 540-fold over this period. The molecular weight pattern of dynorphin 1-17, dynorphin 1-8, dynorphin B, alpha- and beta-neo-endorphin-immunoreactive peptides in the anterior and neurointermediate pituitary did not differ between 3-day-old pups and adult rats. In the neurointermediate pituitary, the major immunoreactive components had the same chromatographic properties as synthetic dynorphin 1-17, dynorphin 1-8, dynorphin B, alpha- and beta-neo-endorphin, respectively, on gel filtration and high-performance liquid chromatography (HPLC). This indicates that neonatal rats were already capable of processing the precursor pro-enkephalin B into these various opioid peptides. In newborn rats, however, the amount of dynorphin 1-8 in the neurointermediate pituitary was three times lower than that of its putative intermediate precursor peptide dynorphin 1-17. Similarly, the amount of beta-neo-endorphin was almost four times lower than that of its putative precursor alpha-neo-endorphin. In contrast, in the neurointermediate pituitary of adult rats, dynorphin 1-17 and dynorphin 1-8, in addition to a alpha- and beta-neo-endorphin, occurred in equimolar amounts.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Ontogenetic development of the pro-enkephalin B (= pro-dynorphin) opioid peptide system in the rat pituitary. 615 Nov 28

Dynorphin (1-17), and to a lesser extent, beta-endorphin and [Leu]enkephalin (10(-6) M each) decreased the spontaneous release of vasopressin (VP) from the rat neurointermediate pituitary in vitro, whereas the oxytocin (OT) release remained unchanged. Naloxone, however, did not significantly alter the spontaneous VP and OT release. Dynorphin (1-17) (10(-7) M) increased the electrically evoked release of VP and OT, while 10(-6) M had a significant, somewhat less pronounced stimulatory effect only on VP, but not on OT release. The opiate inactive fragment [des-Tyr1]dynorphin (1-17) did not change the evoked VP and OT release, indicating that the dynorphin effect was mediated by opiate receptors. beta-Endorphin (10(-6) M and 10(-7) M) did not alter the evoked VP and OT secretion. 10(-6) M [Leu]enkephalin induced a stimulation of the evoked OT, but not VP release; 10(-7) M [Leu]enkephalin had no effect, neither on VP nor on OT release. The opiate antagonist naloxone (10(-5) M) induced an increase in the evoked VP and, even more pronounced, OT release. In a concentration of 10(-6) M, however, naloxone only increased the evoked OT release. When naloxone and dynorphin (1-17) were concomitantly applied, their stimulatory effects on the evoked VP and OT release were additive. Similarly to the effects of naloxone, addition of a monoclonal antibody which binds to the common N-terminal sequence of all endogenous opioid peptides, resulted in a marked increase in the evoked secretion of VP and, to an even more pronounced degree, of OT.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential effects of various opioid peptides on vasopressin and oxytocin release from the rat pituitary in vitro. 615 15

The axonal projections of cell groups containing the most dense collections of steroid hormone concentrating cells have been demonstrated with retrograde neuroanatomical tracing methods. Horseradish peroxidase revealed large numbers of neurons in ventrolateral ventromedial nucleus (VL-VM) which project to dorsal midbrain. Wheat germ agglutinin (immunocytochemical recognition method) revealed large numbers of neurons in medial basal hypothalamus (MBH) and particular subdivisions of paraventricular nucleus (PVN) that project to dorsal caudal medulla or spinal cord. Fluorescent dyes revealed that many preoptic area (POA), anterior hypothalamic (AHA), and bed nucleus of the stria terminalis (BNST) neurons project to ventral tegmental area of Tsai (VTA). Also many neurons in POA and BNST project to amygdala. A method which enabled simultaneous demonstration of the steroid binding capacity and axonal projections of neurons in the same tissue section revealed that 26-36% estradiol (E2) concentrating cells in VL-VM project to dorsal midbrain. E2 concentrating neurons in POA and BNST project to amygdala and E2 concentrating POA neurons project to VTA. These neurons, which send their axons to cell groups located in different brain regions, are probably under the genomic-regulatory influence of E2. Using a method which allows simultaneous demonstration of peptide content and steroid hormone concentrating capacity of cells, many oxytocin-neurophysin and vasopressin-neurophysin containing magnocellular neurons in the caudal PVN were found to concentrate E2. About 4% of the beta-endorphin and about 6% of the dynorphin containing neurons in the MBH concentrate E2. In contrast, virtually none (less than 0.2%) of the LHRH containing hypothalamic neurons concentrate E2.
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PMID:Axonal projections and peptide content of steroid hormone concentrating neurons. 638 52

The presence of opioid peptides and opiate receptors in the hypothalamo-neurohypophysial system, as well as the inhibitory effects of enkephalins and beta-endorphin on release of oxytocin and vasopressin have been well documented. The physiological importance of opioid peptides in this classical neurosecretory system, however, has remained illusive. In the present study we tested the effects of naltrexone on the plasma concentrations of oxytocin and vasopressin during dehydration, hemorrhage and suckling in the conscious rat. We obtained evidence supporting the hypothesis that opioid peptides inhibit oxytocin release and thereby promote the preferential secretion of vasopressin when it is of functional importance to maintain homeostasis during dehydration and hemorrhage. Our data support the concept that the coexistence of a neuromodulator and a neurohormone in the same neuron, as demonstrated for vasopressin with dynorphin or leucine-enkephalin, serves to regulate the differential release of two biologically different, yet evolutionarily-related, neurohormones, e.g. oxytocin and vasopressin, from the same neuroendocrine system.
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PMID:A functional role for opioid peptides in the differential secretion of vasopressin and oxytocin. 654 Oct 75

[he concentrations of immunoreactive (ir-) peptides derived from the opioid peptide precursors proenkephalin A (Met-enkephalin), proenkephalin B [dynorphin (DYN)-(1-17), dynorphin-(1-8), dynorphin B, alpha-neoendorphin (alpha-NEO-E), beta-NEO-E] and proopiomelanocortin [beta-endorphin (beta-END)], and of the neurosecretory hormones vasopressin and oxytocin increased between approximately 10-fold and 50-fold from birth to adulthood in the rate hypothalamus. Gel filtration and HPLC analysis of proenkephalin B-derived opioid peptides revealed that in 3-day-old rats the predominant portion of ir-dynorphin-(1-17) and a substantial part of ir-dynorphin B consisted of a high (6000) mol wt species, a common precursor peptide for DYN-(1-17) and DYN B. In adults rats, however, authentic DYN-(1-17) and DYN B were found to be the major ir-forms. The mol wt patterns of ir-DYN-(1-8), ir-alpha-NEO-E and ir-beta-NEO-E did not differ between 3-day-old and adult rats and reflected predominantly the respective authentic opioid peptides. Taking into consideration the developmental changes in the mol wt pattern of ir-DYN-(1-17), authentic DYN-(1-17) was 5 times lower in concentration than DYN-(1-8) in 3-day-old rats, whereas in adults these opioid peptides occurred in equimolar concentrations. These findings suggest that the posttranslational processing of the precursor proenkephalin B changes in the course of postnatal development. Ir-beta-END in the hypothalamus of newborn and adult rats consisted exclusively of beta-END-sized peptides which were not (unlike those in the intermediate pituitary lobe) alpha-N-acetylated. Thus, in the hypothalamus, the enzymatic processing of the opioid peptide precursor proopiomelanocortin to beta-END seems to be fully active at birth, in contrast to that of proenkephalin B.
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PMID:Evidence for a differential postnatal development of proenkephalin B (= prodynorphin)-derived opioid peptides in the rat hypothalamus. 654 67

Dynorphin-A-(1-8), an opioid peptide widely distributed in the rat central nervous system, is present in vasopressin-containing neurosecretory cells terminating in the neural lobe of the pituitary. Electron microscopic immunocytochemistry reveals that dynorphin-A-(1-8) is contained within the same neurosecretory vesicles as vasopressin and vasopressin-associated neurophysin in the neural lobe of the rat. The results indicate that dynorphin may be released in the pituitary concomitantly with vasopressin during the antidiuretic response.
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PMID:Dynorphin-A-(1-8) is contained within vasopressin neurosecretory vesicles in rat pituitary. 664 26

An antibody raised against dynorphin 1-8 was immunoreactive in the rat neurohypophysis in vasopressin but not in oxytocin endings. Oxytocin but not vasopressin terminals were immunostained when a Met5-enkephalin, a N-terminally directed monoclonal beta-endorphin antibody and an enkephalin-Met5-Arg6-Phe7 antibody were applied. The immunocytochemical reactions indicate that oxytocin terminals and their granules store pro-enkephalin-A derived opioid peptide fragments.
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PMID:An attempt to characterize by immunocytochemical methods the enkephalin-like material in oxytocin endings of the rat neurohypophysis. 666 45

When vasopressin is administered into the lateral ventricles of rats it produces severe convulsive activity characterized by a rapid barrel rotation. Electrical recordings from the dorsal hippocampus indicate marked elevations in the amplitude and frequency at doses of 5 microliter of 2 x 10(-5) M vasopressin. No significant behavioral effects were noted with oxytocin, somatostatin, beta-melanophore-stimulating hormone, adrenocorticotropin, or leu-enkephalin. Pretreatment of the rats with intraventricularly administered oxytocin, beta-MSH, or systemically administered Dilantin prevented the vasopressin-induced seizures. With the use of chemical and enzymic modification procedures, the essential fragment and amino acids of vasopressin needed for the activity were determined. It was concluded that although the peptide could be acting by vasoconstricting blood arterioles and capillaries in the brain, it may also be exerting a direct excitatory action on neurons.
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PMID:Chemical requirements of vasopressins for barrel rotation convulsions and reversal by oxytocin. 740 Nov 98

In order to shed some light on the neurotransmitters in the spinothalamic tract (STT), we examined, biochemically and immunohistochemically, the contents of various neurotransmitter candidates in the terminal field of the STT after cervical hemi-chordotomy (HC) and dorsal quadrant-chordotomy (dQC) in the rat. Substance P (SP), calcitonin gene-related peptide (CGRP), enkephalin, neuropeptide Y, neurotensin, oxytocin and dynorphin A were analyzed immunohistochemically. The contents of neuropeptides (SP, CGRP and cholecystokinin octapeptide) were measured by radioimmunoassay and those of amino acids (aspartic acid, glutamic acid, gamma-aminobutyric acid (GABA) and glycine) and noradrenaline were determined using high-performance liquid chromatography. Cervical hemi-chordotomy, but not dQC, caused significant decreases of the SP-like immunoreactivity in and SP content of the ventral thalamus on the ipsilateral side, compared with that on the contralateral side and of rats subjected to sham-operation. However, neither HC nor dQC resulted in any changes in the ventral thalamic contents of other putative neurotransmitters examined. These results suggest that, in rats, the STT contains SP and that SP-positive fibers run in the ventral half of the ascending spinal tract at the cervical level.
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PMID:Substance P is a possible neurotransmitter in the rat spinothalamic tract. 753 53


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