Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0030193 (pain)
261,466 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The presence of aromatase (estrogen synthase) in neurons in the dorsal horn of the spinal cord in Japanese quail suggests that estrogens produced locally from androgens could control spinal sensory processes including nociception. We used the hot water nociceptive test (54 degrees C) to appraise the long-term effect of an inhibition of aromatization on the foot withdrawal latency in male quail. Four weeks after the ablation of their main source of testosterone (testes), castrated males displayed a significantly higher foot withdrawal latency than gonadally intact males. A prolonged treatment with subcutaneous capsules filled with testosterone or 17 beta-estradiol restored the baseline latency within 2 weeks. The effect of testosterone in castrated quail was almost completely blocked by systemic injections of Vorozole(TM), a nonsteroidal aromatase inhibitor or tamoxifen, an estrogen receptor antagonist (one injection per day for 10 days). Taken together, these data demonstrate for the first time to our knowledge an effect of estrogens formed by aromatization of androgens on nociception. Because aromatase-immunoreactive neurons and aromatase activity are present in the dorsal horns of the spinal cord, this control of pain thresholds is presumably mediated, at least in part, by estrogens produced at the spinal level that act locally via slow, presumably genomic, mechanisms mediated by the activation of spinal nuclear estrogen receptors.
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PMID:Aromatase (estrogen synthase) activity in the dorsal horn of the spinal cord: functional implications. 1499 59

Fulvestrant (Faslodex) is a novel estrogen receptor (ER) antagonist that competitively binds to the ER with a much greater affinity than that of tamoxifen. The downregulation of cellular levels of the ER protein results in complete abrogation of estrogen-sensitive gene transcription. This distinct mechanism of action ensures a lack of cross resistance with other hormonal agents and, in contrast to tamoxifen, fulvestrant has no known estrogen-agonist effects. Fulvestrant is administered via monthly intramuscular injections (250mg) and is recommended for the treatment of hormone receptor-positive metastatic breast cancer in postmenopausal women with disease progression following antiestrogen therapy. The efficacy of fulvestrant was similar to that of the aromatase inhibitor anastrozole (1 mg/day) in two, well designed studies in postmenopausal women with locally advanced or metastatic breast cancer that had progressed during prior antiestrogen therapy. Time to disease progression (primary endpoint) and treatment failure, rates of objective response and clinical benefit, overall survival and quality of life were similar in patients treated with fulvestrant or anastrozole. In retrospective noninferiority analyses, fulvestrant was at least as effective as anastrozole in all randomised patients, and in those with or without visceral metastases. Fulvestrant is generally well tolerated and was tolerated as well as anastrozole in clinical trials. Treatment-related adverse events were mostly mild to moderate and led to treatment withdrawal in about 1% of patients who received fulvestrant or anastrozole. The main adverse effects associated with therapy are nausea, asthenia, pain, vasodilation and headache.In conclusion, monthly intramuscular injections of fulvestrant are at least as effective and as well tolerated as oral anastrozole once daily in the treatment of postmenopausal women with advanced breast cancer that has progressed on prior antiestrogen therapy. Because of a different mode of action to that of other hormonal agents, fulvestrant is effective in the treatment of tamoxifen-resistant disease and, unlike tamoxifen, has no known estrogen agonist effects. Thus, fulvestrant provides an effective and well tolerated option for the treatment of hormone receptor-positive metastatic breast cancer in postmenopausal women with disease progression following antiestrogen therapy.
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PMID:Fulvestrant: a review of its use in hormone receptor-positive metastatic breast cancer in postmenopausal women with disease progression following antiestrogen therapy. 1501 96

The GATA family of transcription factors establishes genetic networks that control developmental processes including hematopoiesis, vasculogenesis, and cardiogenesis. We found that GATA-1 strongly activates transcription of the Tac-2 gene, which encodes proneurokinin-B, a precursor of neurokinin-B (NK-B). Neurokinins function through G protein-coupled transmembrane receptors to mediate diverse physiological responses including pain perception and the control of vascular tone. Whereas an elevated level of NK-B was implicated in pregnancy-associated pre-eclampsia (Page, N. M., Woods, R. J., Gardiner, S. M., Lomthaisong, K., Gladwell, R. T., Butlin, D. J., Manyonda, I. T., and Lowry, P. J. (2000) Nature 405, 797-800), the regulation of NK-B synthesis and function are poorly understood. Tac-2 was expressed in normal murine erythroid cells and was induced upon ex vivo erythropoiesis. An estrogen receptor fusion to GATA-1 (ER-GATA-1) and endogenous GATA-1 both occupied a region of Tac-2 intron-7, which contains two conserved GATA motifs. Genetic complementation analysis in GATA-1-null G1E cells revealed that endogenous GATA-2 occupied the same region of intron-7, and expression of ER-GATA-1 displaced GATA-2 and activated Tac-2 transcription. Erythroid cells did not express neurokinin receptors, whereas aortic and yolk sac endothelial cells differentially expressed neurokinin receptor subtypes. Since NK-B induced cAMP accumulation in yolk sac endothelial cells, these results suggest a new mode of vascular regulation in which GATA-1 controls NK-B synthesis in erythroid cells.
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PMID:Neurokinin-B transcription in erythroid cells: direct activation by the hematopoietic transcription factor GATA-1. 1512 23

Raloxifene, a selective estrogen receptor modulator (SERM) licensed for the prevention of non-traumatic vertebral fractures in postmenopausal women at increased risk of osteoporosis, was launched in the UK in August 1998. The aim of the study was to monitor the safety of raloxifene prescribed in the primary care setting in England using prescription-event monitoring (PEM). Patients were identified by means of prescription data supplied by the Prescription Pricing Authority between September 1998 and November 2000. Demographic and clinical event data were collected from questionnaires posted to primary care physicians (GPs) at least 6 months after the date of the first prescription for each patient. Information on medical events, suspected adverse drug reactions (ADRs), reasons for stopping treatment, pregnancies, and causes of death was requested. Event rates [Incidence Densities (IDs): no. first reports /1000 patient-months of treatment] were calculated. Differences between IDs for events reported in month one (ID(1)) and months 2-6 (ID(2-6)) of treatment were examined. The cohort comprised 13,987 patients [median age 62 years (IQR 55,69); 99.8% female]. The major indication was osteoporosis (40.9%, n=5725). Flushing was the event with the highest ID in month 1 (22.8), reported most frequently by GPs as an ADR to raloxifene (67/461 reports) and as the reason for stopping (700/4592 reports). Events associated with starting treatment included flushing, malaise/lassitude, headache/migraine, nausea/vomiting, sweating, cramp, pain abdomen, dizziness, diarrhea, mastalgia and vaginal hemorrhage. Less common events reported during treatment included deep vein thrombosis (n=13), pulmonary embolism (n=13), thrombophlebitis (n=31) and visual disturbance (n=29). In this study, there were 122 (0.9%) confirmed deaths, of which 32 causes of death were unknown. This study shows that raloxifene is generally well tolerated when used in general practice in England. Potential signals of unrecognised ADRs requiring further evaluation included gastrointestinal adverse symptoms and vaginal hemorrhage. There were also a small number of reports of events associated with venous thromboembolism and visual disorders that require further investigation.
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PMID:Safety profile of raloxifene as used in general practice in England: results of a prescription-event monitoring study. 1530 82

Although many clinical reviews are consistent with the view that hormone replacement therapy should be recommended for increasing bone mass of osteoporotic patients, calcitonin administration is preferable to hormone replacement therapy for the alleviation of pain accompanying osteoporosis, despite the fact that osteoporosis and the accompanying pain are accelerated by the reduction in estrogen levels. Distinct from the clinical view, animal studies have shown that estrogen treatment reduces ovariectomy-induced hyperalgesia, although the mechanism of this phenomenon is unknown. The discrepancy in clinical and animal study outcomes may be due to the timing of administration of estrogen after depletion of the hormone. To address this possibility, the anti-nociceptive effect of estrogen was compared with calcitonin using the tail withdrawal test in rats injected with estrogen or calcitonin at 3 weeks (short term) or 15 weeks (long term) after ovariectomy. Furthermore, we analyzed the change in [3H]8-OH-DPAT binding in the spinal cord, addressing whether estrogen exerts its anti-nociceptive effect by the expression of 5-HT receptors attributable to calcitonin-induced analgesia, as has been reported in our previous animal studies. The present study demonstrates that the administration of estrogen injected in the short term, but not long term, after ovariectomy mimicked the effects of calcitonin-induced anti-nociception and prevention of ovariectomy-induced decrease in 5-HT receptor expression in the spinal cord, although the effects of calcitonin were observed regardless of the timing of calcitonin injection. These results suggest that the estrogen receptor is downregulated gradually after ovariectomy. Disappearance of the estrogen receptor may be one of the reasons that estrogen is not recommended for the treatment for chronic pain associated with osteoporosis.
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PMID:Administration of estrogen shortly after ovariectomy mimics the anti-nociceptive action and change in 5-HT1A-like receptor expression induced by calcitonin in ovariectomized rats. 1533 6

Clinical studies have suggested that postmenopausal women on estrogen replacement treatment are more likely to experience back pain and related disability compared to women who do not take estrogens. Raloxifene, a selective estrogen receptor modulator has estrogen-like effects on bone tissue, and antagonize the action of estrogens on endometrium and breast tissue. It is unknown if the treatment of osteoporosis with raloxifene has estrogen-like or opposite effects on back pain and functional capacity among postmenopausal women with osteoporosis. A total of 120 postmenopausal women with osteoporosis and chronic back pain were randomized to receive raloxifene 60 mg with 1,000 mg calcium, and 800 IU vitamin D daily or 1,000 mg calcium and 800 IU vitamin D daily. Pain intensity and pain-related disability were measured before treatment at 6 months and after 1 year. Repeated measures of ANOVA, did not reveal statistically significant differences over time, on pain intensity and disability scores, between groups studied. There was a trend in pain intensity changes during the follow-up period, but the differences between the groups were not statistically significant. It seems that treatment with raloxifene does not influence back pain and disability among postmenopausal women with osteoporosis. Raloxifene may have estrogenic agonist effects on nociceptive processing in the central nervous system.
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PMID:Does raloxifene treatment influence back pain and disability among postmenopausal women with osteoporosis? 1641 Nov 30

Female rats demonstrate higher pain sensitivity than do males in various nociceptive assays of inflammation. In the present study, we found that estradiol (20%) replacement in ovariectomized rats attenuated the chronic phase of the formalin response but only at high formalin concentrations thought to rely on peripheral inflammation. An inactive isomer of estradiol, alpha-estradiol, failed to result in the same attenuation (P > 0.05). Our results suggest that estradiol's actions in inflammatory responses are mediated through genomic estrogen receptor-mediated mechanisms.
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PMID:Estradiol administration mediates the inflammatory response to formalin in female rats. 1589 95

ATP, an intracellular energy source, is released from cells during tissue stress, damage, or inflammation. The P2X subtype of the ATP receptor is expressed in rat dorsal root ganglion (DRG) cells, spinal cord dorsal horn, and axons in peripheral tissues. ATP binding to P2X receptors on nociceptors generates signals that can be interpreted as pain from damaged tissue. We have hypothesized that tissue stress or damage in the uterine cervix during late pregnancy and parturition can lead to ATP release and sensory signaling via P2X receptors. Consequently, we have examined sensory pathways from the cervix in nonpregnant and pregnant rats for the presence of purinoceptors. Antiserum against the P2X3-receptor subtype showed P2X3- receptor immunoreactivity in axon-like structures of the cervix, in small and medium-sized neurons in the L6/S1 DRG, and in lamina II of the L6/S1 spinal cord segments. Retrograde tracing confirmed the projections of axons of P2X3-receptor-immunoreactive DRG neurons to the cervix. Some P2X3-receptor-positive DRG neurons also expressed estrogen receptor-alpha immunoreactivity and expressed the phosphorylated form of cyclic AMP response-element-binding protein at parturition. Western blots showed a trend toward increases of P2X3-receptor protein between pregnancy (day 10) and parturition (day 22-23) in the cervix, but no significant changes in the DRG or spinal cord. Since serum estrogen rises over pregnancy, estrogen may influence purinoceptors in these DRG neurons. We suggest that receptors responsive to ATP are expressed in uterine cervical afferent nerves that transmit sensory information to the spinal cord at parturition.
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PMID:P2X receptors in the rat uterine cervix, lumbosacral dorsal root ganglia, and spinal cord during pregnancy. 1590 98

A mechanism underlying gender-related differences in pain perception may be estrogen modulation of nociceptive signaling in the peripheral nervous system. In rat, dorsal root ganglion (DRG) neurons express estrogen receptors (ERs) and estrogen rapidly attenuates ATP-induced Ca2+ signaling. To determine which estrogen receptor mediates rapid actions of estrogen, we showed ERalpha and ERbeta expression in DRG neurons from wild-type (WT) female mice by RT-PCR. To study whether ERalpha or ERbeta mediates this response, we compared estradiol action mediating Ca2+ signaling in DRG neurons from WT, ERalpha knockout (ERalphaKO), and ERbetaKO mice in vitro. ATP, an algesic agent, induced [Ca2+]i transients in 48% of small DRG neurons from WT mice. 17beta-Estradiol (E2) inhibited ATP-induced intracellular Ca2+ concentration ([Ca2+]i) with an IC50 of 27 nM. The effect of E2 was rapid (5-min exposure) and stereo specific; 17alpha-estradiol had no effect. E2 action was blocked by the ER antagonist ICI 182,780 (1 microM) in WT mouse. Estradiol coupled to bovine serum albumin (E-6-BSA), which does not penetrate the plasma membrane, had the same effect as E2 did, suggesting that a membrane-associated ER mediated the response. In DRG neurons from ERbetaKO mice, E2 attenuated the ATP-induced [Ca2+]i flux as it did in WT mice, but in DRG neurons from ERalphaKO mice, E2 failed to inhibit the ATP-induced [Ca2+]i increase. These results show that mouse DRG neurons express ERs and the rapid attenuation of ATP-induced [Ca2+]i signaling is mediated by membrane-associated ERalpha.
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PMID:Estrogen receptor-alpha mediates estradiol attenuation of ATP-induced Ca2+ signaling in mouse dorsal root ganglion neurons. 1595 76

Tamoxifen has been widely used for the treatment of estrogen receptor (ER)-positive breast cancer, but its partial agonist activity is considered to limit the efficacy, and cause tumor flare and endometrial cancer. Fulvestrant, on the other hand, binds and degrades ER, thereby acting as a pure anti-estrogen without partial agonist activity. However, due to its low oral bioavailability, fulvestrant has to be intramuscularly administered to patients, which limits the convenience of the drug, and causes pain and inflammation at the site of injection. In search of a patient- friendly pure anti-estrogen, we screened and identified an ER antagonist, CH4893237, which bound to ER with an IC50 value of 1.4 muM and, by oral administration, inhibited estrogen-stimulated uterine growth in ovariectomized mice. CH4893237 reduced the amount of ER at the protein level and impaired the nuclear accumulation of ER, indicating an orally active pure anti-estrogen. Furthermore, CH4893237 inhibited the estrogen-stimulated proliferation of MCF-7, ZR-75-1 and BT-474 cells, and caused a marked growth inhibition of the MCF-7 xenograft in vivo. Thus, CH4893237 will provide an additional option for second-line hormone treatment of breast cancer.
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PMID:Identification of a novel, orally bioavailable estrogen receptor downregulator. 1602 25


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