Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0042963 (vomiting)
 31,883 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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

Health practitioners use many methods and agents to bring on cervical ripening in early pregnancy, such as intracervical tents and pharmacological techniques, to induce a therapeutic abortion. Prostaglandins alter myometrial and cervical tissue and are the most often used pharmacological technique. Reduced collagen concentration, an increase in water volume, an increase in prostaglandins (PGE2, PGI2, and PGF2 alpha), and a change in the glycosaminoglycan (GAG) content coincide with cervical ripening, yet the mechanism responsible for these changes is obscure. Prostaglandins appear to cause the breakdown of collagen or change the GAG/proteoglycan content. Research shows that prostaglandins can initiate cervical ripening at any stage of pregnancy. Estradiol stimulates prostaglandin production thereby al so inducing cervical dilation. Relaxin also demonstrates an ability to ripen the cervix. In addition, mifepristone (RU-486) is gaining acceptance as a cervical ripening agent. In fact, RU-486 and gemeprost have at least 95% success rate compared to 92% for gemeprost alone or 85% with RU-486 alone. The only effective and acceptable prostaglandins to use at gestation of 0-8 weeks are sulprostone, gemeprost, and 9-methylene-PGE2. At t his gestational age, pharmacological modulation is all that is needed. Even though they are effective (abortion rate 90%), side effects are expected to occur (pain, nausea, and vomiting). Similarly, prostaglandin analogues are preferable for cervical ripening in women at 8-12 weeks gestation. Suction curettage or other surgical techniques then are used to remove the conceptus. At 12-16 weeks gestation, many physicians prefer the same protocol as that of 8-12 weeks gestation. Other choose to infuse PGE2 and saline into the amniotic fluid to stimulate uterine contractions. Another procedure at 12-16 weeks involves 1mg vaginal pessaries of gemeprost every 3 hours to ripen the cervix and stimulate contractions. After 16 weeks, the methods for 12-16 weeks still apply.
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PMID:Pharmacological modulation of cervical compliance in the first and second trimesters of pregnancy. 187 72

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 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, diphoresis and restlessness. In hypertensive patients blood pressure responses are complex and are influenced to some extent by secretion. PGI2 stimulates renin secretion by a direct effect on the juxtaglomerular apparatus, and 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 larger 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 defective. Some drugs (cicletanine, thiazides, propranolol) have been shown to stimulate PGI2 synthesis, and inhibition of cyclooxygenase has been shown to abolish their antihypertensive effects. Whether stimulation of PGI2 synthesis affects the antihypertensive efficacy of these drugs is not yet known.
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PMID:Prostacyclin in hypertension. 225 88

Iloprost, a stable prostacyclin analogue, was given by intravenous infusion to 29 patients with severe Raynaud's phenomenon, 26 of whom had systemic sclerosis (SS), and compared with placebo infusion in a double blind crossover trial. Iloprost significantly lessened the number and the severity of attacks compared with placebo. Nine patients expressed a preference for effectiveness of treatment, eight of these in favour of Iloprost. Thermography failed to show any long term effect of Iloprost. Side effects of headache, flushing, nausea, and vomiting were common, and the inconvenience of intravenous administration may limit its routine use.
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PMID:Infusion of iloprost, a prostacyclin analogue, for treatment of Raynaud's phenomenon in systemic sclerosis. 244 71

Early radiation toxicity is characterized by nausea and vomiting. We have previously shown that gastric emptying, gastric motility, and gastric secretion were suppressed after total body exposure to irradiation. In the present studies, we evaluated the relation between vomiting and gastric function in nine rhesus monkeys and explored the possible role of prostaglandins (PG) in these phenomena. The concentration of PG in plasma and gastric juice was determined using a standard radioimmunoassay and gastric acid output was measured concurrently using a marker dilution technique. The animals were studied in the basal state and after total body exposure to 800 cGy 60Co delivered at a rate of 500 cGy/min. Acid output was abolished from 40 min to 2 h after irradiation but had returned to preirradiation levels 2 days later. Plasma PGE2 and PGI2 (as measured by 6-keto-PGF1 alpha determination) were not significantly modified by irradiation. In contrast, irradiation produced an immediate significant increase (P less than 0.05) in gastric juice concentration of PGE2 (318 +/- 80 to 523 +/- 94 pg/ml; mean +/- SE) and PGI2 (230 +/- 36 to 346 +/- 57 pg/ml); both had returned to basal levels 2 days later. Thus, an increase in gastric juice concentration of both PGE2 and PGI2 is associated with the radiation induced suppression of acid output.
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PMID:Effect of ionizing radiation on prostaglandins and gastric secretion in rhesus monkeys. 355 15

Tolfenamic acid (TA), a potent inhibitor of prostaglandin (PG) biosynthesis and action, was tested prophylactically against hangover symptoms in 30 healthy volunteers in a double-blind cross-over study. One capsule of TA (200 mg) or placebo was taken before starting to drink alcohol and another before going to bed. The hangover symptoms were evaluated in the morning. TA was found significantly better than placebo in the subjective evaluation of drug efficacy (p less than 0.001) and in reducing the reported hangover symptoms in general (p less than 0.01). In the TA group, significantly lower symptom scores were obtained for headache (p less than 0.01), and for nausea, vomiting, irritation, tremor, thirst and dryness of mouth (all p less than 0.05). In a separate study with eight participants, plasma levels of PGs were followed during ingestion of alcohol with or without TA. The plasma concentrations of PGE2 and TXB2 (a metabolite of thromboxane A2) were lower in the TA group during alcohol ingestion, while PGF2 alpha and 6-keto-PGF1 alpha (a metabolite of prostacyclin) were unaffected. TXB2 correlated with blood alcohol levels in a U-shaped manner.
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PMID:Hangover headache and prostaglandins: prophylactic treatment with tolfenamic acid. 634 13

The effects of sequential prostacyclin infusions at 2, 4, and 8 ng/kg/min for 1 hr were determined in six patients with chronic renal failure. Diastolic blood pressure decreased in a dose-dependent fashion from 74 +/- 4 mm Hg (mean +/- SEM) to 70 +/- 4, 66 +/- 5, and 55 +/- 5 during the 2, 4, and 8 ng/kg/min infusions, respectively; systolic blood pressure was not affected by prostacyclin. The fall in diastolic blood pressure was associated with a progressive rise in heart rate from 77 +/- 3 to 91 +/- 4 bpm and lowering of body temperature from 36.7 +/- 0.1 to 36 +/- 0.2 degrees. The threshold concentration of adenosine diphosphate that evoked reversible and irreversible platelet aggregation increased progressively from 1.2 to 2.8 and from 2.8 to 6 microM, respectively, during the prostacyclin infusions. Prostacyclin infusions had no effect on prothrombin time, activated partial thromboplastin time, or platelet count, but template bleeding time increased (not statistically significantly) from 5.8 to 12.3 min. In three of six patients, the 8 ng/kg/min infusion was terminated prematurely due to nausea, vomiting, and/or hypotension. We conclude that platelet aggregability can be inhibited in patients with chronic uremia by infusing 4 ng/kg/min prostacyclin without causing untoward side effects. When infused at hemodynamically tolerable doses, prostacyclin might serve as an in vivo inhibitor of platelet aggregation during hemodialysis or cardiopulmonary bypass.
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PMID:Effects of prostacyclin infusion in uremic patients: hematologic and hemodynamic responses. 701 91

Iloprost is a synthetic stable analogue of prostacyclin (PGI2), which shares its antiaggregating and vasodilating properties. Iloprost has been administered by i.v. route to patients with critical limb ischaemia (CLI) of different origin (maximal dosage: 2 ng/kg/min 6 hours/day infusion for 14-28 days). In patients with claudicatio intermittens (Fontaine stage II) iloprost improved the time to claudication and the maximal walking distance on treadmill, with an effect still lasting 60 days after suspension. This benefit was not related to a significant improvement in blood flow. Five multicentric, perspective, randomized versus placebo studies in patients with more severe CLI (Fontaine stage III-IV) susceptible to surgical treatment, showed that iloprost was able to reduce pain and ulcer dimensions. Furthermore, tha amputation rate of the ischemic limb was significantly lower in patients treated with iloprost during a 6 month follow-up (p < 0.01). Iloprost was also more effective than aspirin in causing pain relief and ulcer healing in patients with thromboangiitis obliterans and more effective than nifedipine in reducing frequency, intensity and duration of ischemic episodes in patients with Raynaud's phenomenon. Minor side effects of iloprost administration are represented by facial flushing, tachycardia, headache, nausea, vomiting, abdominal cramping, diarrhoea, whose frequency ranges from 16% to 70%; major collateral effects, occurring in less than 5% of patients, are above all represented by severe hypotension and angina pectoris. Clinical data indicate therefore that iloprost treatment can allow to improve the clinical conditions and the prognosis in patients with critical ischemia of the limbs, not candidate to surgical revascularization, by causing a relief of pain, a reduction in ulcer dimensions and deferring amputation.
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PMID:[The role of iloprost in the treatment of critical ischemia of the limbs]. 750 14

Magnesium (Mg) deficiency occurs frequently in chronic alcoholism and may contribute to the increased incidence of osteoporosis and cardiovascular disease seen in this population. Mg deficiency is primarily due to renal Mg-wasting and is exacerbated by dietary Mg deprivation, gastrointestinal losses with diarrhea or vomiting, as well as concomitant use of drugs such as diuretics and aminoglycosides. Osteoporosis is prevalent in the alcoholic population. Mg deficiency may contribute to increased bone loss by its effects on mineral homeostasis. In Mg depletion, there is often hypocalcemia due to impaired parathyroid hormone (PTH) secretion, as well as renal and skeletal resistance to PTH action. Serum concentrations of 1,25-vitamin D are also low. These changes are seen with even mild degrees of Mg deficiency and may contribute to the metabolic bone disease seen in chronic alcoholics. Hypomagnesemia in alcoholics may also contribute to increased cardiovascular disease by altering platelet function. Mg deficiency has been demonstrated to enhance platelet reactivity. In these studies, Mg was shown to inhibit platelet aggregation against various aggregation agents. Patients with Mg deficiency were shown to have increased platelet aggregation that was normalized with Mg therapy. The antiplatelet effect of Mg may be related to the finding that Mg inhibits the synthesis of thromboxane A2 and 12-hydroxyeicosatetraenoic acid, eicosanoids thought to be involved in platelet aggregation. Mg also inhibits the thrombin-induced Ca2+ influx in platelets, as well as stimulates synthesis of prostaglandin I2, the potent antiaggregatory eicosanoid. Therefore, Mg deficiency may increase platelet aggregation and cause increased hypertension and atherosclerotic cardiovascular disease in alcoholics.
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PMID:Magnesium deficiency in alcoholism: possible contribution to osteoporosis and cardiovascular disease in alcoholics. 784 87

Prostacyclin (PGI2) is a bioactive substance produced by vascular endothelial cells, which exerts powerful vasodilative and anti-platelet actions. Patients with pulmonary hypertension have an imbalance between vasodilative PGI2 and vasoconstrictive thromboxane B2 (TXB2). Treatment with vasodilative agents is essential for such patients. Continuous intravenous infusion of PGI2 is an effective treatment of primary pulmonary hypertension in terms of exercise capacity and survival rate. We tested a new stable PGI2 analogue, beraprost sodium (Procyclin, Dornar) suitable for oral administration, in patients with primary and secondary pulmonary hypertension. A short-term study of cardiac catheterization in four patients with primary pulmonary hypertension showed a 15 +/- 12% reduction in mean pulmonary artery pressure in three of the four patients, and a 24 +/- 22% decrease in pulmonary vascular resistance in all four patients. Cardiac index increased by 27 +/- 14% in three of the four patients. Among three patients with secondary pulmonary hypertension, there was a 7% reduction in pulmonary artery pressure in one patient, and a 24 +/- 14% decrease in pulmonary vascular resistance in all three patients. In a long-term study (23 +/- 11 months), NYHA functional class improved from 3.0 +/- 0.7 to 2.4 +/- 0.5 in two of the five patients with primary pulmonary hypertension. Although the radiographic cardiothoracic ratio was not significantly improved, cardiac index increased by 78 +/- 60% in four of the five patients. Only two patients, one with primary and one with secondary pulmonary hypertension, died during the long-term follow-up period. Plasma TXB2/6-keto prostaglandin F1 alpha ratio decreased from 8.1 +/- 8.7 to 1.5 +/- 0.4. The optimal dose remains uncertain, but the initial dosage of 40-60 micrograms/day given in three to four doses for adult patients is considered to be acceptable. Side effects such as flushing face, headache, vomiting, and nausea were mild and resolved when the dose was reduced. Oral PGI2, beraprost, appears to be an effective and possibly adequate substitute for intravenous vasodilators in pulmonary hypertension for both short- and long-term management.
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PMID:[Short- and long-term effects of the new oral prostacyclin analogue, beraprost sodium, in patients with severe pulmonary hypertension]. 864 6


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