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)

The anteroventral periventricular nucleus (AVPv), which lies in the periventricular zone of the preoptic region, is critical for normal phasic gonadotropin secretion since lesions of this nucleus abolish the progesterone-induced surge of luteinizing hormone secretion from the anterior pituitary, block ovulation, and induce persistent vaginal estrus in female rats. However, very little is known about the neurotransmitter-specific pathways associated with this nucleus. In the present study we evaluated the distribution of biochemically specific cells and fibers within the AVPv and adjacent regions by using an indirect immunohistochemical method with antisera to serotonin (5-HT), dopamine beta-hydroxylase (DBH), tyrosine hydroxylase (TH), neuropeptide Y (NPY), cholecystokinin-8 (CCK), vasoactive intestinal polypeptide (VIP), substance P (SP), neurotensin (NT), corticotropin-releasing factor (CRF), luteotropin-releasing hormone (LRH), somatostatin (SS), thyrotropin-releasing hormone (TRH), oxytocin (OXY), vasopressin (VAS), adrenocorticotropic hormone (ACTH1-24), alpha-melanocyte-stimulating hormone (alpha-MSH), leucine-enkephalin (L-ENK), and calcitonin gene-related peptide (CGRP). Our findings indicate that both cells and fibers containing these putative neurotransmitters are differentially distributed in and around the AVPv in accordance with the cytoarchitectonic organization of this part of the preoptic region. The AVPv itself appears to receive strong inputs from SP-, VAS-, CCK-, and SS-containing pathways, whereas the highest densities of L-ENK-, NT-, 5-HT-, NPY-, and DBH-immunoreactive fibers were found in the cell-sparse zone just lateral to the AVPv. The suprachiasmatic preoptic nucleus (PSCh), a small group of cells located ventral to the AVPv just dorsal to the optic chiasm, contained high densities of alpha-MSH- and ACTH-immunoreactive fibers, as well as substantial numbers of fibers containing catecholamines or NPY. In contrast, a dense plexus of VAS-stained fibers was distributed fairly evenly throughout the AVPv and PSCh. Numerous L-ENK-immunoreactive cell bodies, and moderate numbers of CCK-, NT-, and CRF-stained cell bodies were found in the AVPv. The PSCh contained many TH-stained cells (presumably dopaminergic), in addition to a moderate number of CCK-containing cell bodies, while a high density of NT- and CRF-stained cells were found in the cell-sparse zone lateral to the AVPv, in addition to several CCK-, SP-, VIP-, and TH-containing cells.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The distribution of neurotransmitter-specific cells and fibers in the anteroventral periventricular nucleus: implications for the control of gonadotropin secretion in the rat. 288 Jun 34

Melanin concentrating hormone (MCH) is a heptadecapeptide isolated from chum salmon (Oncorhynchus keta) pituitaries. The peptide has been isolated from whole brain extract at a low yield of 1.2 micrograms/1300 brains. MCH activity in the hypothalamus was characterised by in vitro scale bioassay and radioimmunoassay. Specificity of these assay systems was examined with neurotransmitters such as epinephrine, norepinephrine, and dopamine, hypothalamic hormones such as somatostatin, isotocin, Arg-vasotocin, oxytocin, and Arg-vasopressin, and salmon prolactin and its chymotryptic peptide or salmon PRL176-187. Among them only salmon PRL176-187 exhibited weak activities in both assays. The neurotransmitters were 10(4) to 10(5) times less potent than MCH in the bioassay. MCH concentrations in a pituitary and a hypothalamus were estimated as 5300 +/- 750 ng (ca. 106 micrograms/g) and 48 +/- 9.5 ng (ca. 1.6 micrograms/g), respectively, by radioimmunoassay. Lysyl endopeptidase digestion of the hypothalamic extract resulted in a significant increase of biological activity as well as of immunoreactivity. Gel filtration of the hypothalamic extract and subsequent enzymatic digestion revealed that the fractions at higher molecular weight were contributory to the increase in the activities.
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PMID:Characterization of melanin concentrating hormone in teleost hypothalamus. 288 42

The subcommissural organ (SCO) of the snake Natrix maura was studied by use of the immunoperoxidase procedure. Primary antisera against bovine neurophysins (Nps I + II, OXY-Np), oxytocin (OXY), mesotocin (MST), arginine-vasotocin (AVT), somatostatin (SOM), beta-endorphin (END) and bovine Reissner's fiber were used. A conventional ultrastructural study, with special emphasis on the nerve fibers present in the SCO, was also performed. Nerve fibers containing immunoreactive OXY-Np and MST were seen to reach the SCO. The staining of adjacent sections with the anti-Reissner's fiber serum showed that the OXY-Np- and MST-immunoreactive fibers were distributed among the cell bodies and processes of the ependymal secretory cells. No fibers containing immunoreactive OXY, AVT, SOM or END were found in the SCO. The ultrastructural analysis revealed in the SCO the presence of nerve fibers filled with electron-dense granules, 170-210 nm in diameter. Although a direct apposition between these fibers and the SCO cells was frequently seen, no synaptic differentiations were identified. Structures identical to the Herring bodies (found in the neurohypophysis) were seen in the SCO.
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PMID:Immunocytochemical and ultrastructural evidence for a neurophysinergic innervation of the subcommissural organ of the snake Natrix maura. 288 36

The present investigation examined the distributions of immunoreactive neurotensin (NT), cholecystokinin octapeptide (CCK), substance P (SP), methionine enkephalin (ENK), vasoactive intestinal polypeptide (VIP), somatostatin (SS), rat neurophysin II (RNP II), vasopressin (VP), oxytocin (OXY), tyrosine hydroxylase (TH), and serotonin in the parabrachial nuclear complex (PB) of the rat. All of these substances were localized to the PB and they appeared to be chemoarchitecturally organized within the complex. The lateral subdivision (PBL) was organized medial-lateral and ventral-dorsal. Specifically NT, CCK, and SP immunoreactive fibers were found to be the most dense in the ventral aspect of the PBL. The distribution of NT-containing fibers was similar to the pattern of CCK-containing fibers and these were localized primarily to the central zone of the PBL. Immunoreactive SP fibers and cells were found in the external and internal zones ventrally and surrounding the dorsal and dorsolateral nuclei in the PBL. Somatostatin, ENK and VIP were found to be the most dense in the dorsal PBL. Serotonin- and TH-containing cells and fibers were found in both the PBL and PBM. These results, coupled with the observations of neuronal connections of the PB and the known functions of this region, underscore the potential involvement for these neuropeptides and monoamines in limbic-brainstem mechanisms of autonomic control.
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PMID:Neuropeptide and monoamine components of the parabrachial pontine complex. 288 46

Synaptic organization of the intermediolateral nucleus of the guinea pig thoracic spinal cord was examined with particular focus on monoamine- and peptide-containing nerve terminals. Axon varicosities having flat synaptic vesicles constituted 17% of all axons in the nucleus and formed exclusively symmetric synapses. Enkephalin-, substance P-, somatostatin-, 5-hydroxytryptamine-, and catecholamine-immunoreactive nerve terminals were densely distributed, while neurotensin, vasoactive intestinal polypeptide-, oxytocin-, and cholecystokinin-8-immunoreactive nerves were sparse in the nucleus. Coexistence of 5-hydroxytryptamine and enkephalin was demonstrated, and coexistence of somatostatin and enkephalin as well as somatostatin and 5-hydroxytryptamine in the same axons was also shown by serial semithin sections. Catecholamine axons labelled by 5-hydroxydopamine formed axodendritic and axosomatic synapses and made direct synaptic contacts on the preganglionic sympathetic neurons identified by retrograde transport of horseradish peroxidase. Direct synaptic contacts from enkephalin- and substance P-immunoreactive axons to preganglionic sympathetic neurons were also revealed. Enkephalin-, substance P-, and 5-hydroxytryptamine-immunoreactive axons formed axodendritic and axosomatic synapses. Catecholamine axon varicosities constituted 19% of all axon varicosities in the nucleus and 30% of them showed synaptic specializations in a sectional plane. Axon varicosities immunoreactive to enkephalin, 5-hydroxytryptamine, and substance P constituted approximately 35, 19, and 13% of all axon varicosities, respectively, while those with synaptic contacts made up 27, 30, and 26%, respectively, in a sectional plane. Enkephalin-, 5-hydroxytryptamine-, and noradrenaline-immunoreactive axons showed mainly symmetric synaptic contacts.
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PMID:Synaptic structure of the monoamine and peptide nerve terminals in the intermediolateral nucleus of the guinea pig thoracic spinal cord. 288 97

Immunohistochemistry makes possible the in situ detection of neuropeptides in the cell bodies were they are synthesized, in the fibers that carry them, and in endings. Immunohistochemistry appears necessary to identify and map peptidergic neurons and to study their ontogeny. From 1975, we have carried the immunohistochemical study of several hypothalamic neuronal populations in the human fetus: LH-RH (1976), somatostatin (1977), pro-opiocortin (1978), vasopressin and oxytocin (1979), corticoliberin (1982), somatocrinin (1983), and hypothalamic neurons containing an unidentified peptide (1984). Comparative ontogenetical studies have also been performed in rats.
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PMID:[Contribution of immunocytochemistry to the study of the development of neuroglandular peptidergic systems in the human fetal hypothalamus]. 289 77

In this study we examined the hypothesis that the intermediolateral cell column (IML) of the thoracic spinal cord, the nucleus from which preganglionic sympathetic neurons originate, provides an anatomical substrate through which selective regulation of sympathetic nervous system targets is accomplished. Preganglionic sympathetic neurons of rats were retrogradely labeled by the simultaneous exposure of the cervical sympathetic trunk (CST) and the adrenal medulla to Fluoro-Gold and True blue, contrasting fluorescent dyes. Retrograde labeling from these sites revealed 2 populations of sympathetic preganglionic neurons in IML whose distribution overlapped between segments T1 and T4. In regions where these 2 groups of retrogradely labeled neurons overlapped, sympathoadrenal preganglionic (SAP) neurons occupied the most lateral aspect of the nucleus. It was also determined whether individual retrogradely labeled neurons within these two groups sent axon collaterals to both the CST and adrenal medulla. Diamidino yellow, a fluorescent retrograde tracer dye that labels only nuclei, was substituted for Fluoro-Gold and used in combination with True blue to simultaneously label preganglionic sympathetic neurons projecting to either the CST or adrenal medulla. No double-labeled cell bodies were observed in spinal cords of rats treated in this manner. Thus it appeared that the efferent projections of these 2 cell populations in IML were target-specific. Immunohistochemical analysis of the relationship between nerve fibers in the IML and preganglionic sympathetic neurons was also undertaken in an attempt to classify further these 2 populations of sympathetic preganglionic neurons. Equal proportions of identified CST and SAP neurons appeared to be apposed by varicosities immunoreactive for either somatostatin or serotonin. On the other hand, when the comparison was based on whether oxytocin-immunoreactive varicosities appeared to appose these 2 populations of retrogradely labeled sympathetic neurons, a highly significant difference was revealed. That is, oxytocin-immunoreactive fibers and terminals appeared to avoid SAP neurons. Thus these data support the hypothesis that an anatomical substrate exists in spinal cord IML whereby selective regulation of sympathetic nervous system targets may be mediated. Moreover, the lack of oxytocin-immunoreactive varicosities apposing SAP neurons in IML suggests that if the paraventricular nucleus innervates SAP neurons in IML, it does so via a population of neurons that do not use oxytocin as a neurotransmitter.
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PMID:The intermediolateral cell column of the thoracic spinal cord is comprised of target-specific subnuclei: evidence from retrograde transport studies and immunohistochemistry. 289 66

1. We have reviewed recent studies in which in situ hybridization histochemistry (ISHH) was used to investigate the regulation of expression of neurohypophysial peptides and hypothalamic releasing hormones. 2. ISHH is a technique in which the presence and quantity of a specific mRNA can be determined in tissue sections with a high degree of resolution and sensitivity. 3. ISHH has been used to measure changes in cellular levels of mRNAs encoding vasopressin, oxytocin, corticotropin-releasing factor, gonadotropin-releasing hormone, thyrotropin-releasing hormone and somatostatin in response to various physiological challenges. 4. A theme emerging from these studies is that changes in levels of mRNA encoding neuroendocrine peptides reflect changes in biosynthesis and secretion.
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PMID:Neuroendocrine gene expression in the hypothalamus: in situ hybridization histochemical studies. 289 79

Three putative processing enzymes, each with defined action in a prohormone system, a 'pro-ocytocin-neurophysin convertase' from bovine neurohypophysis secretory granules, a 'Leu-enkephalin Arg6 generating enzyme' from human CSF and the endoprotease from the 'S-28 convertase' complex of rat brain cortex, were tested for their ability to hydrolyze peptides deriving from pro-ocytocin, pro-enkephalin B and pro-somatostatin, respectively at pairs of basic amino acids. The observations suggest that structural parameters specified by the peptide region around the dibasic moieties govern recognition by the enzyme and define which peptide bond is hydrolyzed.
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PMID:Role of peptide substrate structure in the selective processing of peptide prohormones at basic amino acid pairs by endoproteases. 289 32

Using immunohistochemistry, well-preserved neuronal cell bodies and fibres containing neuropeptide Y, somatostatin, and cholecystokinin immunoreactivity have been identified in all seven supratentorial anaplastic astrocytomas studied. These neurones have been shown not only on the edge but also in the depth of the neoplastic tissue. These neuropeptides were not present in 18 other intracranial tumours (3 astrocytomas, 1 subependymoma, 8 glioblastoma multiformes, 1 meningioma, and 5 metastases). In all 25 intracranial tumours studied, no immunoreactivity was found for vasoactive intestinal polypeptide, substance P, methionine-enkephalin, leucine-enkephalin, synenkephalin, neurophysin I-II, and corticotropin releasing factor.
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PMID:Neuropeptide Y, somatostatin, and cholecystokinin neurone preservation in anaplastic astrocytomas. 290 6


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