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

Hybridization histochemistry has bridged molecular biology and neuroanatomy to provide nearly dynamic views of gene expression in the brain--perhaps especially in the hypothalamus. These snapshots of transcript levels with precise anatomical localization have revealed new insights into gene regulation in the hypothalamus under specific conditions. Magnocellular neurons in the paraventricular and supraoptic nuclei produce vasopressin and oxytocin. Transcript levels for these hormones are affected by hyperosmolality, as are those for many other neuropeptides. Patterns of gene expression in the magnocellular neurons in these nuclei during development and under different physiological conditions have been studied less extensively. The parvocellular neurons of the paraventricular nucleus produce corticotropin-releasing factor and thyrotropin-releasing hormone. Expression of the corticotropin-releasing factor gene is regulated by glucocorticoids. Physiological stresses, which activate the hypothalamo-pituitary-adrenal axis, also affect gene expression in the parvocellular paraventricular nucleus. Thyrotropin-releasing hormone is synthesized in a different set of parvocellular neurons in the paraventricular nucleus and in other neurons of the hypothalamus. Expression of the thyrotropin-releasing hormone gene is regulated by thyroid hormone. The suprachiasmatic nucleus contains neurons that produce vasopressin or vasoactive intestinal polypeptide in a circadian rhythm. Future studies using combinations of classical neuroanatomical techniques, hybridization histochemistry and immunohistochemistry will further our understanding of hypothalamic responses to various stimuli.
 ...
PMID:Regulation of gene expression in the hypothalamus: hybridization histochemical studies. 142 21

The placenta is an endocrinologically active organ and expresses an important number of polypeptide hormone genes. Although oxytocin (OT)-like immunoreactivity has been detected in placental extracts by RIA, the precise nature and origin of placental OT has remained unclear. In the present study, we examined OT gene expression in rat placental tissue at various stages of gestation using northern blot analysis, polymerase chain reaction, in situ hybridization, HPLC, and immunocytochemistry. Northern blot analysis of RNA extracted from rat placenta revealed a single type of OT gene transcript (0.66 kilobases) which differed in size from hypothalamic OT transcripts (0.75 kilobases). Deadenylation of placental and hypothalamic messenger RNA (mRNA) showed that this size difference was due to differences in poly(A) tail lengths. Polymerase chain reaction amplification of placental and hypothalamic complementary DNAs using four different exon-specific primers provided no evidence for the existence of any additional structural differences between hypothalamic and placental OT-gene transcripts. Quantitative evaluation of northern blots showed that OT mRNA abundance per microgram of total RNA was stage specific and declined by a factor of 6 from day 14 to day 21 of gestation. In contrast to the marked variation of mRNA abundance, the OT peptide content, as measured by RIA, underwent no significant change during the time period studied and varied between 0.37-0.51 ng/g wet tissue wt. Characterization of placental OT immunoreactivity by HPLC and gel filtration identified two peaks of immunoreactivity: one peak (70% of immunoreactivity) corresponded to synthetic OT; whereas the other peak (Mr 11,000, 30% of immunoreactivity) represented a noncovalent association between OT and another molecule, consistent with the formation of a neurophysin/OT complex. By in situ hybridization and immunocytochemistry, we localized OT mRNA and OT immunoreactivity to cells of the trophoblastic epithelium covering the septa of the labyrinth as well as to cytotrophoblastic elements and giant cells of the maternally derived basal zone of the placenta. Placental OT may act locally, may interact with uterine OT receptors, or may play a role in fetal development.
 ...
PMID:Expression of the oxytocin gene in rat placenta. 153 85

The pituitary hormones prolactin and oxytocin play important roles in the production and ejection of milk. In addition, some gastrointestinal peptides are released in response to suckling. During suckling, the piglets massage the udder of the sow both before and after let-down and the duration of suckling is correlated to the amount of milk produced by the sow. The aim of this study was to investigate whether there is a quantitative relation between the release of prolactin, gastrin, somatostatin, insulin, glucagon and vasoactive intestinal polypeptide (VIP) and the amount of stimulation of the sow's teats by the piglets. Repeated blood samples were drawn from three Swedish Landrace sows during three consecutive nursings by each sow on days 1, 3, 7 and 14 after parturition. The duration of massage by the piglets was noted, as was the number of piglets massaging. Hormone levels were quantified by radioimmunoassay. The release of prolactin, somatostatin, insulin, glucagon and VIP but not of gastrin were found to be significantly related to the amount of teat massage performed by the piglets during the first 2 weeks of lactation. The release was related to the duration of piglet massage or to the combined effect of duration and the number of piglets massaging but not to the number of piglets massaging per se. The basal level of prolactin was found to decrease during this time.
 ...
PMID:Quantitative relationships between suckling-induced teat stimulation and the release of prolactin, gastrin, somatostatin, insulin, glucagon and vasoactive intestinal polypeptide in sows. 168 75

The anterograde Phaseolus vulgaris-leucoagglutinin (PHA-L) tracing technique was used to determine the distribution of efferent fibers originating in the lateral septal nucleus of the guinea pig. For complementary detection of the chemical identity of the target neurons, double-labeling immunocytochemistry was performed with antibodies to PHA-L and to vasopressin, oxytocin, vasoactive intestinal polypeptide, serotonin or dopamine beta-hydroxylase, respectively. The hypothalamus received the majority of the PHA-L-stained septofugal fibers. Here, a specific topography was observed. (1) The medial and lateral preoptic area, (2) the anterior, lateral, dorsal, posterior hypothalamic and retrochiasmatic area, (3) the supraoptic, paraventricular, suprachiasmatic, dorsomedial, caudal ventromedial and arcuate nuclei, and (4) the tuberomammillary, medial and lateral supramammillary, dorsal and ventral premammillary nuclei always contained PHA-L-labeled fibers. The rostral portion of the ventromedial nucleus and the medial and lateral mammillary nucleus only occasionally showed weak terminal labeling. In other diencephalic areas, termination of PHA-L-labeled fibers was observed in the epithalamus and the nuclei of the midline region of the thalamus. In the mesencephalon, terminal varicosities occurred in the ventral tegmental area, interfascicular and interpeduncular nucleus, and periaqueductal gray. In addition, the dorsal and medial raphe nuclei of the metencephalon, together with the locus coeruleus and the dorsal tegmental nucleus, received lateral septal efferents.
 ...
PMID:The efferent connections of the lateral septal nucleus in the guinea pig: projections to the diencephalon and brainstem. 186 17

This review summarizes the revolutionary impact of brain peptides on our understanding of the nervous system and then discusses the localization, distribution, synthesis, receptor sites, and possible function of 32 brain peptides. The peptides are discussed in three subgroups: I) the opioid peptides, which include beta-endorphin, the enkephalins, and dynorphin; II) the pituitary releasing hormones, most of which are wide-spread in the brain and include corticotropin-releasing hormone, luteinizing hormone-releasing hormone, somatostatin, and thyrotropin-releasing hormone; and III) a selection of 12 other peptides potentially important for neurological function, including vasopressin, oxytocin, substance P, cholecystokinin, bombesin, neurotensin, renin, angiotensin, vasoactive intestinal polypeptide, neuropeptide Y, calcitonin gene-related peptide, and calcitonin. Within each individual peptide section, the possible physiological roles in anterior pituitary hormone release, blood-flow regulation, feeding behavior, temperature regulation, nociception, memory and learning, and movement are reviewed. Further, where noted, the peptide findings in Huntington's, Alzheimer's, Parkinson's and psychiatric diseases are emphasized.
 ...
PMID:Neuropeptides. 187 Jul 24

This paper summarizes the recent knowledge on the factors stimulating or inhibiting the adrenocortical growth. In the part I of the present review the following stimulatory growth factors are discussed: ACTH--in vivo, N-POMC derivatives, dibutyryl cAMP--in vivo, GH, Prl, vasopressin, oxytocin, insulin, insulin-like growth factor I (somatomedin C), estradiol and vasoactive intestinal polypeptide (VIP). Among the factors, which inhibit the adrenocortical growth, the following ones are considered: ACTH--in vitro, cAMP--in vitro, adrenal steroids and testicular androgens. The remaining hormones and factors affecting the adrenocortical growth are described in the part II of the review.
 ...
PMID:[Factors stimulating and/or inhibiting growth processes of the adrenal cortex. I. The role of the anterior pituitary and hypothalamic hormones, insulin, sex steroids and certain neuropeptides]. 194 99

The human suprachiasmatic nucleus was analysed by immunohistochemical demonstration of various substances in combination with 3-dimensional computerized reconstruction and video overlay facilities. In the human, the suprachiasmatic nucleus is not as compact as in the rodent. Its boundaries are not easily delineated using conventional stains, and it shows no obvious cytoarchitectonic structure. However, based on its chemoarchitecture, the human suprachiasmatic nucleus can be apportioned into five major subdivisions: Dorsal, comprising a crescent shaped mass of densely packed neurophysin/vasopressin-neurons as well as neurotensin-neurons, and also containing 3-fucosyl-N-acetyl-lactosamine (FAL)-positive neurons in its medial part. Central, occupying the core of the nucleus and consisting precisely of a region devoid of neurophysin/vasopressin neurons but demarcated by calbindin, synaptophysin, and a circumscribed cluster of vasoactive intestinal polypeptide-neurons and containing neurotensin neurons as well. Anteroventrally this division also contains some intermingled neurons positive for neurotensin, neuropeptide Y, somatostatin, and FAL. Ventral, extending from the anterior extreme of the preoptic recess caudolaterally to a field between the optic chiasm and the anteroventral margin of the supraoptic nucleus. This subdivision is specified by synaptophysin, calbindin, and substance P immunoreactivity and is almost free of glial fibrillary acidic protein. From its rostral portion, fibers immunoreactive for calbindin, vasoactive intestinal polypeptide, synaptophysin, and substance P protrude deeply into the optic chiasm. Medial, comprising a thin band between the subependymal zone and the dorsal subdivision, containing scattered somatostatin neurons. External, extending as a band around the dorsal and lateral borders of the nucleus, containing astrocytes expressing the FAL-epitope and scattered neurophysin/vasopressin and neurotensin neurons. These findings indicate that the human suprachiasmatic nucleus contains well-defined subdivisions with different, chemically specific, connections and provides a basis for comparing these subdivisions with the structure and function of subdivisions previously described for the suprachiasmatic nucleus in experimental animals. In addition, the findings strengthen the concept that the human suprachiasmatic nucleus generates and expresses circadian rhythms in a manner similar to that documented for the suprachiasmatic nucleus in experimental animals, and suggest that different subdivisions may subserve specific functional roles.
 ...
PMID:Evidence for subdivisions in the human suprachiasmatic nucleus. 203 18

The effects of vasoactive intestinal polypeptide (VIP), of a selective oxytocin antagonist and of GABA on basal and stimulated oxytocin and vasopressin release from isolated neurosecretory endings were investigated. Superfusion of the secretosomes with VIP (10(-7) M) induced an increased basal and stimulated release of both oxytocin and vasopressin. Addition of the oxytocin antagonist induced a decrease of the stimulated oxytocin release as compared to the control which indicated a positive feedback mechanism of oxytocin on oxytocin release. In presence of GABA (1 or 50 microM) no change in basal or stimulated oxytocin and vasopressin release was observed.
 ...
PMID:Modulation of oxytocin and vasopressin release from rat neurosecretosomes: the roles of VIP oxytocin and GABA. 206 99

The aim of the present study was to measure plasma levels of vasoactive intestinal polypeptide (VIP) and oxytocin following suckling, electrical stimulation of the mammary nerve and oxytocin infusion in lactating rats. Trunk blood was collected by decapitation after 5 and 20 min of suckling in conscious lactating rats. Repeated blood samples were drawn from the carotid artery in anesthetized rats, in connection with suckling, oxytocin infusion (0.22 nmol/l/kg/h) and electrical stimulation of the mammary nerve (5 V, 5 Hz, 2 ms). VIP and oxytocin levels were measured by radioimmunoassay. In conscious rats, VIP levels rose significantly from 18 +/- 5 to 102 +/- 30 pM after 5 min of suckling and to 123 +/- 25 pM after 20 min of suckling when milk ejection occurred. Oxytocin levels rose significantly from 90 +/- 24 to 269 +/- 45 pM during milk ejection. Suckling, oxytocin infusion and mammary nerve stimulation in anesthetized rats raised VIP levels significantly from 13 +/- 2, 18 +/- 5 and 10 +/- 2 to 43 +/- 8, 45 +/- 16 and 53 +/- 22 pM, respectively, whereas oxytocin levels rose from 111 +/- 34 to 294 +/- 66 pM after 20 min of suckling and to a peak value of 500 +/- 70 pM after oxytocin infusion. This study shows that VIP is elevated in plasma in lactating rats when the pups are suckling. The results showing that VIP levels rise following mammary nerve stimulation and oxytocin infusions indicate that both neurogenic and hormonal mechanisms can contribute to the regulation of VIP levels in plasma.
 ...
PMID:Plasma levels of vasoactive intestinal polypeptide and oxytocin in response to suckling, electrical stimulation of the mammary nerve and oxytocin infusion in rats. 210 67

The structural organization of small peptides reproducing the amino acid sequence of the common ocytocin/neurophysin precursor around the LysArg cleavage locus was investigated by a combination of spectroscopical techniques. In water both circular dichroism and [1H] NMR spectra indicated that these peptides adopted a random conformation. Evidence for folded structures was obtained when these compounds were placed in a membrane-like environment i.e. 40 mM SDS in phosphate buffer or trifluoroethanol. Whereas the CD spectra indicated the formation of various types of beta-turn in rapid equilibrium, measurements of NH temperature coefficients and Nuclear Overhauser Effects by 400 and 500 MHz NMR revealed the existence of contacts and of a folded conformation. These observations are discussed in relation with previous hypothesis made on the secondary structure organization of the proteolytic processing site of polypeptide hormone precursors.
 ...
PMID:Evidence for beta-turn structure in model peptides reproducing pro-ocytocin/neurophysin proteolytic processing site. 213 68


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>