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)

Physiological roles have been suggested for prostacyclin in the cardiovascular system. Prostacyclin was administered by intravenous infusion to unanesthetized rats. Over a 24 hr period, 0.32 mg/kg/day caused only flushing of the ears. Larger doses (0.56 and 1 mg/kg/day) caused hypothermia, behavioral depression, and swelling of the paws. Cumulative dose-response curves for its depressor action were determined in both unanesthetized and anesthetized, vagotomized, ganglion-blocked rats. In unanesthetized rats, the threshold dose was about 0.1 ug/kg/min. Respiratory depression precluded doses larger than 1 ug/kg/min. In anesthetized rats, the threshold dose was about 0.001 ug/kg/min, and the maximally effective dose was about 0.1 micrograms/kg/min. At 0.032 ug/kg/min, blood pressure first fell and then rose slightly. This compensatory rise did not occur in nephrectomized rats, suggesting renin release as the mechanism. Intravenous infusion of 0.1 but not 0.01 ug/kg/min in unanesthetized rats doubled plasma renin activity. In saline-loaded unanesthetized rats, urine volume and urinary sodium excretion were decreased by 0.1 ug/kg/min of prostacyclin.
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PMID:The cardiovascular pharmacology of prostacyclin (PGI2) in the rat. 37 17

Iloprost is an analogue of epoprostenol (prostacyclin; PGI2; a potent but short-lived prostanoid mainly produced in the vascular endothelium) and mimics the pharmacodynamic properties of this compound, namely: inhibition of platelet aggregation, vasodilatation and, as yet ill-defined, cytoprotection. Improved metabolic and, in particular, chemical stability enhance the clinical utility of iloprost. When administered as an intermittent intravenous infusion at less than or equal to 2 ng/kg/min for 2 to 4 weeks, iloprost reduced rest pain and improved ulcer healing in 40 to 60% of patients with critical leg ischaemia, including diabetic patients, and delayed amputation in the majority of responding individuals. Similar benefits have been seen in thromboangiitis obliterans and, in patients with severe Raynaud's phenomenon, shorter courses of therapy reduced the frequency, intensity and duration of ischaemic episodes for at least 6 weeks. The very few comparative trials reported to date (i.e. vs nifedipine in Raynaud's phenomenon; vs low-dose aspirin in thromboangiitis obliterans) have favoured iloprost, but comparisons with more established agents are needed to assess this drug's value in less severe forms of peripheral ischaemia, such as intermittent claudication. At present, iloprost is administered intravenously and this is a limitation to treatment. The potent, rapidly reversible antiplatelet activity of iloprost suits it for use in extracorporeal circulation and for the intraoperative management of heparin-induced platelet activation. Although results in animal models of ischaemic myocardial injury are encouraging, preliminary clinical experience in patients with myocardial ischaemia or infarction has been disappointing. Most patients tolerate iloprost infusion rates of up to 2 ng/kg/min. Headache and flushing are extremely common and are the suggested end-point of dose titration, as higher doses are associated with a significant incidence of gastrointestinal distress and, ultimately, hypotension. Thus, iloprost provides a pharmacotherapeutic option for patients with severe peripheral vascular disease, a condition for which few alternative drug therapies exist. Its potent but short-lived effects make it well-suited to certain therapeutic niches such as the management of intraoperative platelet activation. Prostanoid analogues have far-reaching therapeutic potential and further experience with iloprost will no doubt help to define its clinical applications.
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PMID:Iloprost. A review of its pharmacodynamic and pharmacokinetic properties, and therapeutic potential in peripheral vascular disease, myocardial ischaemia and extracorporeal circulation procedures. 137 60

The effects of lung traction on arterial blood pressure and plasma prostacyclin concentrations were studied in five patients undergoing partial pneumonectomy or lobectomy. After manual traction of a lung segment, mean arterial blood pressure decreased from 77 +/- 5 mm Hg (mean +/- SEM, before lung traction) to 59 +/- 5 mm Hg. The concentrations of 6-keto prostaglandin F1 alpha (a stable breakdown product of prostacyclin) increased significantly from 46 +/- 6 pg/mL (mean +/- SEM, before thoracotomy) to 593 +/- 91 pg/mL. Four of five patients showed facial flushing and palmar erythema. Arterial blood pressure returned to pretraction value, and both the facial flushing and palmar erythema disappeared within 30 min after lung traction. These results suggest that traction of the lung stimulates release and/or production of prostacyclin, which results in facial flushing, palmar erythema, and decrease in arterial blood pressure.
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PMID:Lung traction causes an increase in plasma prostacyclin concentration and decrease in mean arterial blood pressure. 141 33

Prostacyclin (PGI2) is known to cause vasorelaxation and inhibit platelet aggregation by receptor-mediated mechanisms. While cyclic (c) AMP is known to act as a second messenger for inhibition of platelet aggregation, vasorelaxation by hyperpolarization has been described only recently and may provide an explanation, in addition to stimulation of cAMP for the PGI2 mechanism of action on blood vessels. When PGI2 is infused into healthy volunteers it reduces blood pressure only at infusion rates that also cause significant side-effects, primarily, nausea, emesis, flushing, diaphoresis, and restlessness. In hypertensive patients blood-pressure responses are complex and are influenced to some extent by renin secretion. PGI2 stimulates renin secretion by a direct effect on the juxtaglomerular apparatus, and it also has an indirect effect by activating the sympathetic nervous system. Thus, it is useless as an antihypertensive agent even apart from its debilitating side-effects. Vascular PGI2 is synthesized endogenously by both the endothelial cells and the muscularis of arteries. While the endothelial cells undoubtedly synthesize large amounts of PGI2, the muscularis comprises a much larger tissue mass so that the overall synthesis is about equally distributed between the endothelial and muscle cells. In patients with pregnancy-induced hypertension and some patients with essential hypertension endogenous synthesis of PGI2 has been evaluated by measuring 2,3-dinor-6-keto-PGF1 alpha and has proved to be greatly reduced. Some drugs (thiazides, propranolol) have been shown to stimulate PGI2 synthesis, and inhibition of cyclooxygenase has been shown to reduce their antihypertensive effects. The effects of low- and high-dose aspirin on prostacyclin and thromboxane synthesis are discussed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Prostacyclin in hypertension]. 149 51

The efficacy of iloprost, a stable prostacyclin analog, was investigated in a placebo-controlled trial in 109 diabetics with ischemic lesions. 56 patients were randomly allocated to iloprost and 53 patients to placebo. Iloprost was intravenously applied for 6 hours daily on 28 consecutive days at an individually tolerated dose up to 2 ng/kg/min. The control group received identical solvent volumes. In addition all patients had an intensive basic, mainly local, therapy. At the end of the treatment in the iloprost group 31 of 50 patients (62%) showed partial (greater than 30%) or total healing of the lesion(s). In the placebo group this was the case in 12 of 51 patients (22.5%). The difference of 38.5% was statistically significant (p less than 0.05, chi 2-test, alpha = 0.05, beta = 0.1). The percentage of patients who were free of pain increased from 23% to 42% (+19%) in the iloprost group and from 38% to 48% (+10%) in the placebo group. After dose-titration iloprost was well tolerated. Flush, headache and abdominal complaints were the most frequent side effects. Heart rate and blood pressure were not influenced and the control of diabetes was not altered.
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PMID:[Iloprost in the treatment of ischemic tissue lesions in diabetics. Results of a placebo-controlled multicenter study with a stable prostacyclin derivative]. 169 72

The clinical efficacy of the prostacyclin analogue iloprost was studied during a 2 week treatment and 6 month follow-up period in 103 patients with ischaemic ulcers who were randomised to receive active treatment or placebo. Responders were defined as those patients who achieved healing of at least one third of the ulcer area during the study period. The overall responder rate was 41.3%, compared with 25% for the control group (P = 0.086). Side effects including flushing and headache, were common. The study population had a mortality of 23% during the 6 month period, the amputation rate was 43.5% for iloprost and 50% for placebo treated patients. In this severely diseased population of patients a treatment period limited to 2 weeks did not sufficiently improve ulcer healing.
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PMID:A stable prostacyclin analogue (iloprost) in the treatment of ischaemic ulcers of the lower limb. A Scandinavian-Polish placebo controlled, randomised multicenter study. 169 14

We have used an isolated rat lung model to compare the quality of preservation of different flush techniques with each other and with topical cooling alone. Lung injury was assessed by recording lung weights after reperfusion after 4 and 6 hours of ischemia. The flush solutions studied were intracellular (Collins-Sacks), traditional extracellular, extracellular with low potassium plus dextran, and extracellular containing blood, mannitol, albumin, and prostacyclin (Wallwork's solution). Flushing with Wallwork's solution before both 4 and 6 hours of ischemia gave superior protection from lung edema after reperfusion over all the other methods.
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PMID:Extracellular flush solution that contains blood, mannitol, albumin, and prostacyclin protects rat lungs from six hours of ischemia. 175 65

The role of prostaglandin E1 (PgE1) and prostacyclin in enhancing the ischemic tolerance of single-lung grafts was investigated. Fifteen donor dogs underwent pulmonary artery flushing with 60 mL/kg of 4 degrees C modified Euro-Collins solution; 5 dogs each received a 15-minute infusion of PgE1, prostacyclin, or saline solution before flushing. After 12 hours of storage at 4 degrees C, left lung transplantation was performed in 15 recipient dogs. Measurements were performed after 10 minutes of right pulmonary artery snaring before transplantation, after transplantation, and after 2, 4, and 6 hours of reperfusion. At 6 hours, the oxygen tensions (on 100% O2) were 478 +/- 64, 296 +/- 75, 79 +/- 12, and 71 +/- 23 mm Hg in control (nontransplanted), prostacyclin-, PgE1-, and saline-treated dogs, respectively (p less than 0.05, prostacyclin or control versus saline and PgE1 dogs). Mean pulmonary artery pressures increased within each group during reperfusion, but were not significantly different among groups. Similarly, peak inspiratory pressures and wet weight to dry weight ratios were not significantly different among groups after 6 hours of reperfusion. We conclude that donor pretreatment with prostacyclin is associated with superior oxygen transfer in canine lung allografts after 12 hours of cold storage, transplantation, and 6 hours of reperfusion. In this model, donor pretreatment with PgE1 conferred no benefit to prolonged lung allograft preservation.
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PMID:Prolonged preservation of canine lung allografts: the role of prostaglandins. 202 3

This randomized, double-blind study investigated the effect of ciprostene, a stable epoprostenol (prostacyclin) analog in patients with peripheral vascular disease (PVD) characterized by ischemic ulcers. A total of 211 patients (106 ciprostene, 105 placebo) received IV infusions of ciprostene (120 ng/kg/min in 8-hour daily infusions for 7 days) or placebo. The two groups were comparable with regard to demographic data. Only 45% of the patients receiving ciprostene and 55% of the placebo patients completed the trial. The groups were similar in frequency of amputations, vascular surgery, and development of new ulcers. Among those who completed the trials an insignificantly higher percentage of patients receiving ciprostene had all ulcers heal completely. The reduction of ulcer size by at least 50% was higher in the ciprostene-treated group at month 4 (P = .005). Both ciprostene and placebo reduced the severity of a patient's rest pain. There was no difference in the ankle brachial index between the groups. Ciprostene induced a higher incidence of headache, nausea, and flushing during infusion when compared with the placebo group. The results confirmed inherent problems with studies in PVD, namely, scarcity of patients with ischemic ulcers, inclusion of severely ill patients leading to a high dropout rate, and a high placebo effect. Good tolerance and safety of ciprostene was documented in this patient population, and the therapeutic benefit was limited to partial reduction of ulcer size. Selection of patients with less advanced disease and a longer infusion of ciprostene may improve the clinical benefit of this agent.
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PMID:The effect of ciprostene in patients with peripheral vascular disease (PVD) characterized by ischemic ulcers. The Ciprostene Study Group. 204 33

Mesenteric traction during aortic surgery produces facial flushing, reduced mean arterial pressure (MAP), and systemic vascular resistance (SVR) with increased heart rate (HR) and cardiac index (CI). Elevated 6-keto-prostaglandin-F1 alpha (6-keto-PGF1 alpha) suggests prostacyclin is the mediator. To test this hypothesis, the cyclooxygenase inhibitor, ibuprofen (n = 14), or placebo (n = 13) was administered to patients electively scheduled for aortic reconstruction. The hemodynamic measurements and plasma concentrations of prostanoids between groups were compared immediately before (0), and 5, 10, 15, 30, and 45 min following mesenteric traction. Following mesenteric traction significant differences (P less than 0.05) were observed between the ibuprofen pretreatment and placebo group over time in SVR, MAP, HR, CI, 6-keto-PGF1 alpha, and thromboxane B2 (TXB2). Significant differences between groups at individual times were found in SVR, HR, CI, 6-keto-PGF1 alpha, and TXB2. In the placebo group flushing was accompanied by reduced SVR and MAP and increased HR and CI. The greatest effect was seen at 10 min and resolved over 30 min. Plasma concentration of 6-keto-PGF1 alpha increased from 159 +/- 103 (mean +/- SEM) pg/ml to a peak value of 3,765 +/- 803 at 10 min. A late increase in TXB2 occurred with a peak value of 1,970 +/- 891 (mean +/- SEM) pg/ml at 30 min. In the ibuprofen pretreated group no significant changes occurred in hemodynamic measurements or concentrations of prostanoids. The inhibition of 6-keto-PGF1 alpha and its associated hemodynamic changes in the treatment group, but not in the placebo group, confirms the hypothesis that prostacyclin is the mediator of the mesenteric traction response in abdominal aortic surgery.
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PMID:Ibuprofen pretreatment inhibits prostacyclin release during abdominal exploration in aortic surgery. 210 6


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