Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The present study was performed in order to explore the influence of ova present within rat oviducts on: a) tubal spontaneous motility and b) oviduct prostaglandin production. It was found that the isometric developed tension (IDT) of tubes isolated from proestrous rats (preovulatory oviducts) was significantly higher (P less than 0.01) than the IDT of tubes from rats at estrus and at metestrus (postovulatory oviducts). After flushing the oviducts with KRB solution (i.e., after removing existing ova) the IDT of the oviducts obtained from estrous rats increased significantly (P less than 0.01), whereas the IDT of tubes isolated from proestrous rats (i.e., preparations without ova) was not modified. On the other hand, isolated tubes containing their corresponding ova released into the suspending solution significantly more PGE1 than PGE2 or PGF2 alpha (P less than 0.005). It was particularly interesting to find that after flushing the oviducts, tissue production of PGE1, PGE2 and PGF2 alpha was similar. Finally, when dose response curves for PGE1 and for PGE2 on the spontaneous contractions of oviducts isolated from rats at proestrus, estrus and metestrus were constructed, both PGs evoked an inhibitory inotropic action. The ED50 for PGE1 in tubes from estrous rats was significantly smaller (P less than 0.01) than that for metestrous animals but significantly greater (P less than 0.01) than that observed in oviducts from proestrous rats. The ED50 for PGE2 did not change in the different tested periods of the sex cycle. Results reported herein suggest the possibility that the ova present within rat oviducts, may influence their own transport along the tubes by modifying the amount of prostaglandins produced by the oviducts or via their own prostaglandin synthesis.
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PMID:Influence of ova within rat oviducts on spontaneous motility and on prostaglandin production. 225 Dec 92

Nicotinic acid (niacin) is a B vitamin which is also a potent hypolipidemic agent. However, intense flushing occurs following ingestion of pharmacologic doses of niacin which greatly limits its usefulness in treating hyperlipidemias. Previous studies have demonstrated that niacin-induced flushing can be substantially attenuated by pre-treatment with cyclooxygenase inhibitors, suggesting that the vasodilation is mediated by a prostaglandin. However, the prostaglandin that presumably mediates the flush has not been conclusively determined. In this study we report the finding that ingestion of niacin evokes the release of markedly increased quantities of PGD2 in vivo in humans. PGD2 release was assessed by quantification of the PGD2 metabolite, 9 alpha, 11 beta-PGF2, in plasma by gas chromatography mass spectrometry. Following ingestion of 500 mg of niacin in three normal volunteers, intense flushing occurred and plasma levels of 9 alpha, 11 beta-PGF2 were found to increase dramatically by 800, 430, and 535-fold. Levels of 9 alpha, 11 beta-PGF2 reached a maximum between 12 and 45 min. after ingesting niacin and subsequently declined to near normal levels by 2-4 hours. Levels of 9 alpha, 11 beta-PGF2 in plasma correlated with the intensity and duration of flushing that occurred in the 3 volunteers. Release of PGD2 was not accompanied by a release of histamine which was assessed by quantification of plasma levels of the histamine metabolite, N tau-methylhistamine. This suggests that the origin of the PGD2 release is not the mast cell. Only a modest increase (approximately 2-fold) in the urinary excretion of the prostacyclin metabolite, 2,3-dinor-6-keto-PGF1 alpha, occurred following ingestion of niacin and no increase in the excretion of the major urinary metabolite of PGE2 was found. These results indicate that the major vasodilatory PG released following ingestion of niacin is PGD2. The fact that markedly increased quantities of PGD2 are released suggests that PGD2 is the mediator of niacin-induced vasodilation in humans.
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PMID:Release of markedly increased quantities of prostaglandin D2 in vivo in humans following the administration of nicotinic acid. 247 89

Resistance of hypoxic cells to radiation and chemotherapy remains a major limitation to effective therapy of solid tumors. Misonidazole, a 2-nitroimidazole analogue, has been studied extensively as a radiosensitizer of hypoxic cells and has been shown to undergo bioreductive metabolism to exert preferential cytotoxicity against hypoxic cells. We have investigated the effects of misonidazole on the biosynthesis of prostaglandins (PGs) in a murine mammary adenocarcinoma cell line (No. 4526) under aerobic and hypoxic conditions in attempts to exploit modulation of PG levels under hypoxia as a means of improving therapeutic approaches for the treatment of solid tumors. We report a time-dependent inhibition of PG biosynthesis by the suspended cells under hypoxia induced by flushing sealed vials with N2 (1.5 liters/min). After 30 min of hypoxia, PG formation was inhibited by 50%. Indomethacin was able to further inhibit the PG formation in a concentration-dependent manner under hypoxia. Misonidazole, however, selectively increased the PGE2 biosynthesis under hypoxia by 49% at 100 microM. This increase was concentration dependent over the range of 25 to 100 microM and was blocked by indomethacin (0.1 microM). Imidazole, the heterocyclic moiety in misonidazole without the nitro function, had no effect on PG biosynthesis at these concentrations. These data suggest that arachidonic acid metabolism is sensitive to the differential oxygen levels which exist within solid tumors and that PG levels may be modulated by electron-affinic agents in hypoxic tumor cells.
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PMID:Modulation of prostaglandin biosynthesis in hypoxic murine mammary adenocarcinoma cells by misonidazole. 273 27

The relation of plasma levels of prostaglandins to the occurrence of flushing induced by niceritrol was investigated. Niceritrol increased plasma levels of PGE2 (p less than 0.01) and 6 keto-PGF1 alpha (p less than 0.05) in 10 male subjects and aspirin reduced the level of PGE2 (p less than 0.01). Five of 10 subjects had flushing, and aspirin reduced flushing in 4 subjects. On the basis of the above study, we treated 35 hyperlipidemic patients with niceritrol in combination with aspirin, investigating the effect of the treatment of serum lipids and postheparin lipolytic activity. None of the 12 cases given aspirin from the start of the treatment experienced flushing, whereas 9 of the 23 cases not given aspirin experienced flushing, which was suppressed by adding aspirin in prescription in all cases except one. Niceritrol decreased serum cholesterol, triglyceride and atherogenic index. It also increased HDL2 cholesterol and decreased HDL3 cholesterol. The LPL activity in postheparin plasma increased in all cases after niceritrol treatment. In conclusion, aspirin increased compliance of niceritrol by reducing the occurrence of flushing probably due to the decreased levels of prostaglandins, yielding favorable results for the long-term treatment of hyperlipidemia with a sufficient doses of niceritrol.
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PMID:Increased compliance of niceritrol treatment by addition of aspirin: relationship between changes in prostaglandins and skin flushing. 348 59

An unnatural prostaglandin (PG) (prepared by biosynthesis using the method described by Vonkerman et al.) was used to terminate midtrimester pregnancy in 3 primiparous patients aged 21-24. The PG was administered intravenously using a Palmer slow infusion pump. The patients were monitored continuously with particular attention given to pulse, respiration, blood pressure, uterine contractions and cervical dilatation. All 3 cases successfully aborted. Effective infusion rate was similar to that of PGE1 and PGE2 (5-6 mcg/minute) and side effects were trivial (minimal skin flushing, vomiting, mild urticarial reaction). 2 of the patients aborted 8 and 22 hours after infusion stopped without being conscious of continuing uterine activity; the 3rd patient necessitated infusion on the 2nd day and exhibited increased response to the infusion; however, the PG supply was exhausted and syntocinon infusion facilitated the complete abortion. This study shows that this synthetic prostaglandin containing an uneven number of carbon atoms is pharmacologically active and can induce contractions in the intact human pregnant uterus.
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PMID:The use of an "unnatural" prostaglandin in the termination of pregnancy. 555 13

Prostaglandin E(1) (PGE(1)) is widely used to improve early graft function after lung transplantation, but some studies have questioned its benefits. Therefore we evaluated the effect of donor pretreatment with PGE(1) in our porcine model of single lung transplantation. Donors received PGE(1) or placebo intravenously before flushing the pulmonary artery with modified Euro-Collins solution. After cold storage, the excised left lung was transplanted. Ischemic time was 4 h. We used our right side heart bypass model to measure standardized pulmonary vascular resistance and to study blood flow distribution between recipient's native and transplanted lung. Systemic and pulmonary hemodynamics and gas exchange were also measured. After transplantation, pulmonary vascular resistance was significantly higher in the transplanted lung, which received only one fourth of the total pulmonary blood flow. PGE(1) pretreatment did not improve pulmonary hemodynamic parameters, or gas exchange.
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PMID:Donor lung pretreatment with prostaglandin E(1) does not improve lung graft preservation. 1052 57

The antidyslipidemic drug nicotinic acid and the antipsoriatic drug monomethyl fumarate induce cutaneous flushing through activation of G protein-coupled receptor 109A (GPR109A). Flushing is a troublesome side effect of nicotinic acid, but may be a direct reflection of the wanted effects of monomethyl fumarate. Here we analyzed the mechanisms underlying GPR109A-mediated flushing and show that both Langerhans cells and keratinocytes express GPR109A in mice. Using cell ablation approaches and transgenic cell type-specific GPR109A expression in Gpr109a-/- mice, we have provided evidence that the early phase of flushing depends on GPR109A expressed on Langerhans cells, whereas the late phase is mediated by GPR109A expressed on keratinocytes. Interestingly, the first phase of flushing was blocked by a selective cyclooxygenase-1 (COX-1) inhibitor, and the late phase was sensitive to a selective COX-2 inhibitor. Both monomethyl fumarate and nicotinic acid induced PGE2 formation in isolated keratinocytes through activation of GPR109A and COX-2. Thus, the early and late phases of the GPR109A-mediated cutaneous flushing reaction involve different epidermal cell types and prostanoid-forming enzymes. These data will help to guide new efficient approaches to mitigate nicotinic acid-induced flushing and may help to exploit the potential antipsoriatic effects of GPR109A agonists in the skin.
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PMID:Nicotinic acid- and monomethyl fumarate-induced flushing involves GPR109A expressed by keratinocytes and COX-2-dependent prostanoid formation in mice. 2066 68