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)

Total cellular RNA was isolated from conceptus tissue obtained from 22 superovulated cows 18 days after artificial insemination. Total RNA was also isolated from luteal tissue from 3 cyclic cows 7 and 8 days after oestrus. Luteal and conceptus RNA were simultaneously subjected to formaldehyde-agarose gel electrophoresis and transferred to nitrocellulose by bidirectional diffusion blotting. Northern blots were probed using cDNAs specific for bovine oxytocin and bovine beta-actin gene sequences. Hybridization of the oxytocin cDNA to RNA was consistently observed on autoradiographs as a 0.6 kilobase (kb) band in lanes containing corpus luteum RNA, but was not detected in lanes containing conceptus RNA. The presence of conceptus RNA on the blots was confirmed by hybridization of the actin cDNA to conceptus RNA, which resulted in a 2.0 kb band on autoradiographs. These results suggest that oxytocin is not synthesized by the bovine conceptus on Day 18 of gestation.
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PMID:Absence of oxytocin-neurophysin messenger RNA in the day-18 bovine conceptus. 199 64

Cold exposure increases blood levels of TSH and thyroid hormones by stimulating the secretion of TRH from the median eminence. Thyroid hormones reduce TRH release and cellular levels of TRH mRNA. Using quantitative in situ hybridization to measure changes in cellular levels of various neuropeptide mRNAs, the present studies demonstrate that cold exposure also increases cellular levels of TRH mRNA in neurons of the paraventricular nucleus (PVN), supporting the concept that TRH mRNA levels are reflective of TRH secretion in these neurons. The effect of cold appeared to be specific for TRH expression in the PVN, because cold exposure did not influence cellular levels of TRH in the reticular thalamic nucleus or beta-actin and oxytocin mRNAs in the PVN. Cellular levels of mRNA encoding CRH were elevated by cold exposure. This latter observation is predictable based on the cold-induced activation of the hypothalamic-pituitary-adrenal axis. There was a 24-h rhythm and a time of day difference in the effect of cold on TRH mRNA levels in the PVN. Time of day differences in the effect of cold on CRH mRNA levels were not apparent. Cold exposure appeared to elevate TRH mRNA levels in all neurons of the PVN, indicating that the neurally mediated effect of cold on TRH expression can override the inhibitory effects of circulating T3 within the same neuronal population.
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PMID:Cold exposure elevates cellular levels of messenger ribonucleic acid encoding thyrotropin-releasing hormone in paraventricular nucleus despite elevated levels of thyroid hormones. 212 45

An attempt was made to improve gene transfer into chick embryos in order to produce transgenic chickens. The beta-actin-lacZ/MiwZ, a marker gene in transfection reagent, was injected into the blastodisc of either unincubated fertilized eggs (stage X) or eggs induced from the shell gland by treating the hens intravenously with oxytocin or arginine vasotocin (stages IV-VI). All the manipulated embryos were incubated to reach stage XIV, the period at which primordial germ cells (PGCs) migrate from the germinal crescent to the gonadal anlage via the blood stream. MiwZ was detected in the embryos, extraembryonic tissues and blood by the histochemical staining method of beta-galactosidase. The MiwZ DNA was detected in 57% (127/221) of the survival embryos and in 9% (12/127) of the embryonic tissues. The expression was observed mosaically in the epidermis, heart and neural tube. The PGCs in the blood collected from the vitelline artery or dorsal aorta also showed a positive histochemical staining. However, the expression of MiwZ using the soft shelled eggs was more intense in the extraembryonic tissues, although it did not emerge in the embryos. Thus, it is possible to introduce an exogenous gene into the embryonic tissues using incubated fertilized eggs without sacrificing the hens. This technique for successive genetic operations should facilitate the production of transgenic chickens.
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PMID:In vivo gene transfer into the blastoderm of early developmental stage of chicken. 911 91

PGs are important regulators of reproductive processes. At the time ofluteolysis in vivo, PGF2alpha is produced by endometrial cells, in response to oxytocin (OT). The mechanism by which OT induces the release of PGF2alpha remains to be defined. We have used 13 different cultures of bovine epithelial endometrial cells to study the effect of OT on the regulation of PGF2alpha and to identify the possible involvement of cyclooxygenases (COXs). OT induced a dose-dependent increase of both inositol phosphates (IPs) and [Ca2+]i concentration in epithelial cells labeled with [3H]-myoinositol or loaded with fura-2 (using a fluorescent microscope imaging system), respectively. OT induced a dose-dependent increase of both PGF2alpha production and COX-2 gene expression (as demonstrated by RT-PCR and Northern blots). PGF2alpha production was increased from 13.3 +/- 2.0 to 166.8 +/- 22.5 ng/ml (P < 0.0001). On the other hand, COX-2/beta-actin mRNA gene expression (as determined by densitometric analysis) was increased 5.1 +/- 0.7-fold (P < 0.001) with OT (10[-7] M) treatment, compared with control. Addition of indomethacin (1 microM) and a specific COX-2 inhibitor (NS-398, 1 microM) blocked the OT-induced PGF2alpha production. COX-1 and phospholipase A2 mRNA were expressed at steady-state levels, but no effect of OT was detected on their regulation. Combined to OT, 10 microq/ml of recombinant ovine interferon-tau (roIFN-tau) was able to decrease significantly (P < 0.0001) the dose-dependent increase of PGF2alpha production. Furthermore, partial bovine COX-1 (777 pb) and COX-2 (449 bp) cDNAs were cloned and sequenced. An homology of 83% and 97% was found in relation with rat and sheep, for COX-1, respectively. COX-2 was found to bear 84%, 86%, and 87% of homology in relation to rat, guinea pig, and human, respectively. Collectively, these results demonstrate, for the first time, that COX-2 is involved in the mechanism by which OT regulates PGF2alpha production in the endometrium.
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PMID:Cellular mechanisms involved during oxytocin-induced prostaglandin F2alpha production in endometrial epithelial cells in vitro: role of cyclooxygenase-2. 934 8

1. GABAA receptor-mediated synaptic innervation of oxytocin neurones in the supraoptic nucleus (SON) was analysed in adult female rats going through their first reproductive cycle by recording the spontaneous inhibitory postsynaptic currents (sIPSCs) at six stages of female reproduction. 2. During pregnancy we observed a reduction in the interval between monoquantal sIPSCs. The synaptic current amplitude, current decay and neurosteroid sensitivity of postsynaptic GABAA receptors observed at this stage were not distinguishable from those measured in virgin stage SON. 3. Upon parturition an increase in monoquantal synaptic current decay occurred, whereas potentiation by the progesterone metabolite allopregnanolone (3alpha-OH-DHP) was suppressed. 4. Throughout a substantial part of the lactation period the decay of synaptic currents remained attenuated, whilst the potentiation by 3alpha-OH-DHP remained suppressed. 5. Several weeks after the end of lactation sIPSC intervals, their current decay velocity as well as the potentiation by 3alpha-OH-DHP were restored to pre-pregnancy levels, which is indicative of the cyclical nature of synaptic plasticity in the adult SON. 6. Competitive polymerase chain reaction (PCR) analysis showed that virgin animals expressed alpha1 and alpha2 GABAA receptor subunit mRNA at a relative ratio of 2 : 1 compared with beta-actin. After pregnancy both alpha1 and alpha2 subunit mRNA levels were transiently increased, although at a relative ratio of 1 : 4, in line with the hypothesis that alpha2 plays a large role in postsynaptic receptor functioning. During post-lactation both alpha subunits were downregulated. 7. We propose that synaptic remodelling in the SON during pregnancy includes changes in the putative number of GABA release sites per neurone. At parturition, and during the two consecutive weeks of lactation, a subtype of postsynaptic GABAA receptors was observed, distinct from the one being expressed before and during pregnancy. Synaptic current densities, calculated in order to compare the impact of synaptic inhibition, showed that, in particular, the differences in 3alpha-OH-DHP potentiation of these two distinct GABAA receptor subtypes produce robust shifts in the impact of synaptic inhibition of oxytocin neurones at the different stages of female reproduction.
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PMID:Changes in properties and neurosteroid regulation of GABAergic synapses in the supraoptic nucleus during the mammalian female reproductive cycle. 1039 49

We have previously shown that exercise training activates nucleus tractus solitarii (NTS) oxytocinergic projections, resulting in blunted exercise tachycardia. The objective of this study was to determine the effects of hypertension and training on oxytocin (OT) and OT receptor expression in the hypothalamic paraventricular nucleus (PVN) and projection areas (dorsal brain stem [DBS]). Male, normotensive, Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats were trained (55% maximal exercise capacity, 3 months) or kept sedentary, and pressure was measured weekly. DBS sections were processed for immunohistochemistry (polyclonal guinea pig anti-OT) or in situ hybridization for OT and OT receptor (35S-oligonucleotide probes). Other groups of rats had brains removed and frozen to isolate the DBS and PVN; samples were processed for OT and OT receptor cDNA reverse transcription-polymerase chain reaction amplification with beta-actin as the housekeeping gene. Training was equally effective in improving running distance in both groups, with pressure reduction only in SHR (-10%, P<0.05). In trained WKY, baseline bradycardia (P<0.05) occurred simultaneously with increased NTS OT immunostaining and mRNA expression (+3.5-fold), without any change in OT receptor mRNA expression. PVN OT mRNA and DBS OT receptor mRNA expressions were significantly lower in SHR versus WKY (-39% and -56%, respectively). Training did not alter DBS OT receptor density in the SHR group but increased OT mRNA in both PVN and DBS areas (+78% and +45%, respectively). Our results show a marked hypertension-induced reduction in OT receptor mRNA expression, not altered by training. In contrast, training increased OT mRNA expression in sedentary and hypertensive rats, which may facilitate training-induced cardiac performance.
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PMID:Hypertension and exercise training differentially affect oxytocin and oxytocin receptor expression in the brain. 1615 94

Bone morphogenetic proteins (BMPs) and their receptors are expressed in ovarian theca cells (TC) and granulosa cells (GC) and BMPs have been implicated in the regulation of several aspects of follicle development including thecal androgen production and granulosal oestrogen production. Their potential involvement in luteal function has received less attention. In this study, we first compared relative abundance of mRNA transcripts for BMPs, activin-betaA and BMP/activin receptors in bovine corpus luteum (CL) and follicular theca and granulosa layers before undertaking functional in vitro experiments to test the effect of selected ligands (BMP6 and activin A) on luteinizing bovine TC and GC. Relative to beta-actin transcript abundance, CL tissue contained more BMP4 and -6 mRNA than granulosa, more BMP2 mRNA than theca but much less activin-betaA mRNA than both granulosa and theca. Transcripts for all seven BMP/activin receptors were readily detected in each tissue and two transcripts (BMPRII, ActRIIA) were more abundant in CL than either theca or granulosa, consistent with tissue responsiveness. In vitro luteinization of TC and GC from antral follicles (4-6 mm) was achieved by culturing with 5% serum for 6 days. Treatment with BMP6 (0, 2, 10, and 50 ng/ml) and activin A (0, 2, 10 and 50 ng/ml) under these conditions dose-dependently suppressed forskolin-induced progesterone (P4) secretion from both cell types without affecting cell number. BMP6 reduced forskolin-stimulated upregulation of STAR mRNA and raised 'basal' CYP17A1 mRNA level in theca-lutein cells without affecting expression of CYP11A1 or hydroxy-Delta-5-steroid dehydrogenase, 3 beta- and steroid Delta-isomerase 1 (HSD3B1). In granulosa-lutein cells, STAR transcript abundance was not affected by BMP6, whereas forskolin-induced expression of CYP11A1, HSD3B1, CYP19A1 and oxytocin transcripts was reduced. In both cell types, follistatin attenuated the suppressive effect of activin A and BMP6 on forskolin-induced P4 secretion but had no effect alone. Granulosa-lutein cells secreted low levels of endogenous activin A ( approximately 1 ng/ml); BMP6 reduced this, while raising follistatin secretion thus decreasing activin A:follistatin ratio. Collectively, these findings support inhibitory roles for BMP/activin signalling in luteinization and steroidogenesis in both TC and GC.
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PMID:Evidence for an inhibitory role of bone morphogenetic protein(s) in the follicular-luteal transition in cattle. 1893 84