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)

An improved bioassay for the testing of oxytocic compounds by the use of myometrium layer preparations has been developed and proved with synthetic oxytocin. The oxytocic activity of synthetic analogues was testes with this bioassay and compared to oxytocin. The myometrial layer preparation was demonstrated to be reliable, the vitality of the tissue is found for more than 8 hours. The sensitivity of the bioassay is found in the region of 10(-11) Mol/l oxytocin, the maximum of the stimulation of muscle strips varied from 5 X 10(-5) IU/ml to 10(-4) IU/ml oxytocin in the organ-bath. The concentration of the myometrium strips showed two different phases. Only the initial phase can be used for this bioassay. The calculation of the results was afforded planimetrically and by measuring of the concentration-maximum during the testing period. The synthetic hormone analogues [1-desamino-4-alpha-aminobutyric acid] lysine-vasotocin (2) and [4 alpha-aminobutyric acid] lysine-vasotocin had oxytocic activity and the myometrium was activated to contractions at 10(-8) Mol/1. The analogue 2 was 5-10 more active than 3. The contraction maximum for both analogues was found between 5 X 10(-6) and 5 X 10(-5) Mol/l. The induction of the concentration for both analogues varied with the factor 10(5).
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PMID:[A bioassay for the testing of the oxytocic effect of hormone analogs of the neurohypophysis and the pineal body]. 404 79

Neuronal peptides exert neurohormonal and neurotransmitter (neuromodulator) functions in the central nervous system (CNS). Besides these functions, a group of neuropeptides may have a capacity to create cell proliferation, growth, and survival. Axotomy induces transient (1-21 d) upregulation of synthesis and gene expression of neuropeptides, such as galanin, corticotropin releasing factor, dynorphin, calcitonin gene-related peptide, vasoactive intestinal polypeptide, cholecystokinin, angiotensin II, and neuropeptide Y. These neuropeptides are colocalized with "classic" neurotransmitters (acetylcholine, aspartate, glutamate) or neurohormones (vasopressin, oxytocin) that are downregulated by axotomy in the same neuronal cells. It is more likely that neuronal cells, in response to axotomy, increase expression of neuropeptides that promote their survival and regeneration, and may downregulate substances related to their transmitter or secretory activities.
Mol Neurobiol
PMID:Neuropeptide messenger plasticity in the CNS neurons following axotomy. 757 12

This study investigated the underlying mechanisms of oxytocin (OT)-induced increases in intracellular Ca2+ concentrations ([Ca2+]i) in acutely dispersed myometrial cells from prepartum sows. A dose-dependent increase in [Ca2+]i was induced by OT (0.1 nM to 1 microM) in the presence and absence of extracellular Ca2+ ([Ca2+]e). [Ca2+]i was elevated by OT in a biphasic pattern, with a spike followed by a sustained plateau in the presence of [Ca2+]e. However, in the absence of [Ca2+]e, the [Ca2+]i response to OT became monophasic with a lower amplitude and no plateau, and this monophasic increase was abolished by pretreatment with ionomycin, a Ca2+ ionophore. Administration of OT (1 microM) for 15 sec increased inositol 1,4,5-trisphosphate (IP3) formation by 61%. Pretreatment with pertussis toxin (PTX, 1 microgram/ml) for 2 hr failed to alter the OT-induced increase in [Ca2+]i and IP3 formation. U-73122 (30 nM to 3 microM), a phospholipase C (PLC) inhibitor, depressed the rise in [Ca2+]i by OT dose dependently. U-73122 (3 microM) also abolished the OT-induced IP3 formation. Thapsigargin (2 microM), an inhibitor of Ca(2+)-ATPase in the endoplasmic reticulum, did not increase [Ca2+]i. However, it did time-dependently inhibit the OT-induced increase in [Ca2+]i. Nimodipine (1 microM), a voltage-dependent Ca2+ channel (VDCC) blocker, inhibited the OT-induced plateau by 26%. La3+ (1 mM), a nonspecific Ca2+ channel blocker, abrogated the OT-induced plateau. In whole-cell patch-clamp studies used to evaluate VDCC activities, OT (0.1 microM) increased Ca2+ current (ICa) by 40% with no apparent changes in the current-voltage relationship.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Reprod Dev 1995 May
PMID:Oxytocin induced a biphasic increase in the intracellular Ca2+ concentration of porcine myometrial cells: participation of a pertussis toxin-insensitive G-protein, inositol 1,4,5-trisphosphate-sensitive Ca2+ pool, and Ca2+ channels. 761 2

The objective of this study was to test the hypothesis that, in human myometrial cells (HMC), PGF2 alpha and oxytocin promote the release of arachidonic acid (AA) which, in turn, acts to mobilize intracellular Ca2+. Primary monolayer cultures of HMC were labeled with [3H]arachidonic acid ([3H]AA) to isotopic equilibrium before exposure to PGF2 alpha or oxytocin. Radiolabeled phospholipids were separated on thin layer chromatography and quantitated by scintillation counting. Prostanoids were analyzed by high performance liquid chromatography. Calcium release was quantitated in digitonin-permeabilized myocytes preloaded with 45Ca, in the presence of ATP and ruthenium red. PGF2 alpha (10(-7) M) caused a rapid (peaking at 2 min), and significant (P < 0.01) increase in [3H]AA release that was derived selectively from phosphatidylethanolamine (PE), indicative of phospholipase A2 activation. Oxytocin caused a rapid (30 s) and significant increase in diacylglycerol, concomitant with a drop in phosphoinositides, as well as an increase in [3H]AA and a fall in PE and phosphatidylcholine. Exogenous AA caused a rapid and dose-related efflux of 45Ca2+, which was not inhibited by blockers of AA metabolism, or by heparin that abolished inositol 1,4,5-trisphosphate-induced 45Ca2+ release. It is concluded that PGF2 alpha and oxytocin promote, by different mechanisms, the release of AA, which in turn may amplify their action by enhancing Ca2+ mobilization from the sarcoplasmic reticulum, thereby fulfilling the role of intracellular signaling molecule in human myometrium.
Mol Cell Endocrinol 1995 Apr 28
PMID:Proposed signaling role of arachidonic acid in human myometrium. 767 41

We determined the nucleotide sequences of cDNAs encoding precursors of vasotocin (VT) from two cyclostomes, the lamprey Lampetra japonica and the hagfish Eptatretus burgeri, for estimation of their phylogenetic relationships. Although only 47% similarity was found between the VT cDNAs, the predicted VT precursors of the lamprey and the hagfish were both composed of a single peptide, VT, Gly-Lys-Arg and a neurophysin, as has been shown for precursors of vasopressin (VP) family hormones, including VP, VT and molluscan conopressin. The central region of the lamprey neurophysin was very similar to those of previously characterized gnathostome neurophysins. Conspicuously, all the positions of 14 Cys residues were conserved in the lamprey neurophysin. The C-terminal region did not have a distinctive Leu-rich core segment, which is always found in the glycopeptide (copeptin) moiety of VP precursors. In contrast, the hagfish neurophysin showed at least two insertions and one deletion in the conserved central region including 14 Cys residues, but contained a potential N-linked glycosylation site and had a high proportion of Leu residues in the C-terminal region, like the neurophysin of another hagfish, Eptatretus stouti. The evolutionary relationships of the precursors of VP family hormones among the lamprey, hagfish, gnathostomes and a mollusc were estimated by a maximum likelihood method. The phylogenetic tree with the highest bootstrap probability showed that the lamprey VT precursor is more closely related to the gnathostome VT and VP precursors than to the hagfish VT precursors.
J Mol Endocrinol 1995 Feb
PMID:Sequence analysis of vasotocin cDNAs of the lamprey, Lampetra japonica, and the hagfish, Eptatretus burgeri: evolution of cyclostome vasotocin precursors. 777 41

The nucleotide sequence of a cDNA encoding an isotocin hormone precursor has been elucidated by analyzing a lambda ZAPII library constructed using poly(A)+ RNA from the brain of the cartilaginous fish Torpedo marmorata. The sequence predicts a precursor of 126 amino acid residues that consists of a signal peptide, the isotocin moiety, and a neurophysin carrier protein. In contrast to other known fish isotocin precursor sequences, the Torpedo neurophysin moiety is not extended at its carboxy-terminus by a copeptin-like sequence. The T. marmorata isotocin precursor exhibits highest amino acid sequence identity (61%) to the toad mesotocin precursor. As demonstrated by in situ hybridization, the isotocin mRNA is present in neurons of the preoptic area of the Torpedo brain.
Mol Mar Biol Biotechnol 1995 Jun
PMID:Sequence analysis of a cDNA encoding an isotocin precursor and localization of the corresponding mRNA in the brain of the cartilaginous fish Torpedo marmorata. 777 35

The effect of electrical stimulation of an important forebrain autonomic structure, the central nucleus of the amygdala (CNA), on c-fos expression in three hypothalamic nuclei was studied in rat with immunocytochemistry to reveal the protein (Fos) encoded by the immediate early gene (IEG). Image analysis was used to quantify the Fos immunoreactive neurons within the supraoptic (SON), paraventricular (PVN), and arcuate (AN) nuclei. Stimulation for 60 min induced a statistically significant increase of the number of Fos immunoreactive neurons in all three nuclei ipsilateral to the CNA stimulation site. Double immunocytochemical staining (Fos and vasopressin or Fos and oxytocin) was employed to evaluate the participation of different subpopulations of neurons within the SON and PVN in response to CNA stimulation. In the SON, the increased number of Fos immunoreactive nuclei following the stimulation was observed in the vasopressin and oxytocin-secreting cells within this nucleus. In the PVN, the increase in the number of Fos immunoreactive neurons was predominantly within the parvocellular compartment. These studies demonstrate that IEG expression in hypothalamic neurons can be evoked as a result of afferent stimulation from the CNA. Activation of peptide- and hormone-containing neurons within the SON, PVN and AN, through mono- or multisynaptic pathways, may play a role in hormonal and autonomic responses.
Brain Res Mol Brain Res 1994 Mar
PMID:Electrical stimulation of the central nucleus of the amygdala induces fos-like immunoreactivity in the hypothalamus of the rat: a quantitative study. 801 90

Hypothalamic neurosecretory neurons transcribe, translate, store, and secrete a large number of chemical messengers. The neurons contain hypothalamic signal substances that regulate the secretion of anterior pituitary hormones as well as the neurohypophysial peptides vasopressin and oxytocin. In addition to the classical hypophysiotropic hormones, a large number of neuropeptides and classical transmitters of amine and amino acid nature are present in the same cells. This is particularly evident in the magnocellular neurons of the supraoptic and paraventricular nuclei, and in parvocellular neurons of the arcuate and paraventricular nuclei. The changes in gene expression induced by experimental manipulations and the colocalization chemical messengers in hypothalamic neurosecretory neurons and its possible significance is summarized in this review.
Mol Neurobiol 1993
PMID:Gene expression and chemical diversity in hypothalamic neurosecretory neurons. 810 91

Over the last 20 years several observations at the peptide level have indicated the possible existence of additional members of the vasopressin (VP)-oxytocin (OT) gene family in mammals. In this study, the human genome was analyzed for the existence of genes structurally related to the VP and OT genes. Human genomic blots probed under low stringency conditions with exon B of the human OT gene, that codes for the conserved constant region of neurophysin, revealed the presence of two distinct bands in addition to the known VP and OT gene fragments. Five clones were obtained from a library of genomic EcoRI fragments ranging from 4-8 kb, that comprised both low stringency signals, by low stringency hybridization with the OT exon B probe. One clone of 7 kb hybridized at high stringency conditions to bands of the same size as previously detected with OT exon B on a human genomic blot. However, no similarity was observed between the open reading frames of this clone and the neurophysin portion of the OT gene. Another clone of 4.8 kb was identical to a fragment of the gene for the human bone morphogenetic factor hBMP-6, a member of the TGF-beta family. The hBMP-6 gene was not detected by low stringency hybridization of the human genomic blot with the OT exon B probe. No significant similarity was found between the amino acid sequences of human OT neurophysin and hBMP-6. Therefore, no evidence can be provided that the human genome contains additional neurophysin-related genes.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Cell Endocrinol 1993 Dec
PMID:The human vasopressin-oxytocin gene family: no evidence for additional neurophysin-related genes. 814 15

Secretion of the antidiuretic hormone (ADH) vasopressin is increased when body fluid homeostasis is disturbed by dehydration. Associated with this increased secretion is an elevation of vasopressin mRNA in magnocellular hypothalamic neurons projecting to the posterior pituitary. The proto-oncogene c-fos codes for a nuclear phospho-protein Fos which binds to specific DNA elements and acts as a transcriptional regulator coupling short-term extracellular stimuli to long-term responses by altering secondary target gene expression. This study in rats examined the time courses of dehydration induced c-fos expression and the change of vasopressin gene expression in the magnocellular neurons of the hypothalamus. Immunocytochemical and in situ hybridization study demonstrated that c-fos was induced by acute intracellular dehydration in the hypothalamic magnocellular nuclei of paraventricular (PVN), supraoptic (SON), and accessory groups such as nucleus circularis. Double-label immunocytochemical study co-localized Fos and vasopressin-neurophysin immunoreactivity in the same magnocellular neurons in the SON and PVN. In situ hybridization analysis after acute dehydration revealed a rapid and transient c-fos induction followed by a persistent increase in vasopressin mRNA for up to 2 days even after rehydration. Furthermore, prevention of c-fos translation by pretreatment with protein synthesis inhibitor cycloheximide attenuated this dehydration induced increase in vasopressin mRNA. This study demonstrated that an increase in vasopressin transcription after acute dehydration is dependent on an early phase of protein synthesis.
Brain Res Mol Brain Res 1994 Feb
PMID:Proto-oncogene c-fos and the regulation of vasopressin gene expression during dehydration. 817 Mar 49


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