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)

SK&F 101926, a synthetic peptide, is a potent antagonist of vasopressin at both the V2 and the V1 receptors. Following intravenous administration of SK&F 101926 (5 mg/kg), mean arterial pressure (MAP) immediately fell 75 mm Hg. Heart rate increased approximately 50 beats/min. Cutaneous flushing and cyanosis appeared approximately 2 to 5 min after the SK&F 101926 administration. Three of the five rats died within 40 min with no improvement in either color or MAP. The two surviving animals slowly recovered from these symptoms. The hypotension and flushing recorded in these studies resembled the effects during hypotensive shock. SK&F 101926 degranulated rat peritoneal mast cells in vitro as measured by the liberation of histamine. Analogs of SK&F 101926 were identified having reduced activity to release histamine from mast cells in vitro. The activity of these analogs to release histamine in vivo was also tested, as reflected by rat paw edema. A positive correlation was found between the potency to produce edema in vivo and the potency to release mast cell histamine in vitro (r = 0.94, p less than 0.05). In addition, compounds that released mast cell histamine and induced rat paw edema also produced hypotension and death when administered intravenously, while analogs which produced minimal histamine release in vitro produced minimal or no cardiovascular changes or lethality in vivo at the same dosages (5 mg/kg). Finally, cyproheptadine (10 mg/kg), an antagonist at both the serotonin and the histamine receptors, blunted the effects of SK&F 101926 on MAP and blocked the lethality. Pretreatment with a combination of histamine (H1 and H2) antagonists provided little protection against the SK&F 101926-induced toxicity. These data indicate that the cardiovascular toxicity of SK&F 101926 (and related peptides) is mediated via the release of autocoids from mast cells. Serotonin appears to play a major role in mediating the cardiovascular toxicity of SK&F 101926.
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PMID:Hypotension induced by vasopressin antagonists in rats: role of mast cell degranulation. 168 65

Following an intravenous injection of 100 micrograms hCRH a facial flushing can frequently be observed along with respiratory stimulation. Both effects can be mediated by a common transmitter. Serotonin is well known to produce facial flush as well as to modulate respiration. In order to clarify is serotonin is a common mediator for facial flush and respiratory stimulation after i.v. application of hCRH, we studied the time course of facial skin temperatures and respiratory stimulation after intravenous injection of 100 micrograms hCRH in 10 healthy subjects. Furthermore, we measured respiratory stimulation after i.v. administration of 100 micrograms hCRH in 10 healthy subjects pretreated with the serotonin antagonist cyproheptadine. Facial skin temperatures reached maximum levels 9 min after CRH administration and remained raised for more than 60 min. Respiratory stimulation occurred within the first minute after CRH administration and reached a maximum during the second minute, but could no longer be observed after 10 min. Serum serotonin levels did not change after CRH stimulation in doses up to 3 micrograms/kg body weight), and cyproheptadine did not abolish the respiratory stimulation effect of hCRH in a dosage sufficient to suppress CRH.-induced cortisol secretion.
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PMID:Studies on facial temperature rise and involvement of serotonin in the respiratory stimulation by CRH. 176 Dec 82

Serotonin (5-HT) and substance P (SP) were assayed in peripheral blood in patients with known midgut carcinoids and hepatic metastases. All patients had supranormal basal levels of 5-HT and SP. The clinical and hormonal response was evaluated by two provocation tests, pentagastrin (PG) injection or calcium infusion. Pentagastrin caused flushing and gastrointestinal symptoms and elevated levels of circulating 5-HT, but not of SP. Pretreatment with a 5-HT2 receptor blocking agent (ketanserin) alleviated gastrointestinal symptoms but had no influence on either 5-HT release or PG-induced flushing. Calcium infusion induced carcinoid symptoms in only two of six patients, which were associated with elevated 5-HT levels (whereas elevated SP levels were seen in only one patient). We conclude that 5-HT is important for the development of gastrointestinal symptoms but not of flushing. Ketanserin may alleviate gastrointestinal symptoms but does not influence PG-induced release of 5-HT. Substance P and 5-HT do not seem to share a common release mechanism. It appears that PG testing is superior to calcium infusion as a provocative test in patients with the carcinoid syndrome.
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PMID:The pentagastrin test in the diagnosis of the carcinoid syndrome. 241 67

The levels of 5-hydroxytryptamine (serotonin, 5-HT) and substance P (SP) were assayed (using high performance liquid chromatography-electron capture and radioimmunoassay methods) in the peripheral blood of 17 patients with known mid-gut carcinoids, 16 of whom had hepatic metastases. All patients had supranormal basal levels of 5-HT and SP. The clinical and hormonal changes induced by two provocation tests, intravenous pentagastrin (PG) and calcium infusion, were compared. Pentagastrin caused flushing in all the patients, induced gastrointestinal symptoms in all but one of the patients with hepatic involvement, and universally elevated circulating 5-HT levels. Pretreatment with a 5-HT2-receptor blocking agent, ketanserin, abolished the gastrointestinal effects but had virtually no influence on either 5-HT levels or flushing induced by intravenous pentagastrin. In contrast, calcium infusion induced carcinoid symptoms in only two of six patients, and this was consistently associated with stimulation of circulating serotonin levels. The authors conclude that 1) 5-HT may be responsible for the gastrointestinal symptoms in carcinoid patients, but it does not seem to play any role in flushing; 2) ketanserin may be a useful therapeutic agent in alleviating gastrointestinal symptoms in carcinoid patients; 3) differential responses to PG suggests that SP is released from a site different from that of 5-HT; 4) it is possible that SP may contribute to the mediation of flushing, but it cannot be the sole agent causing this symptom; and 5) the pentagastrin test with measurements of 5-HT levels in peripheral blood seems to be superior to calcium infusion as a provocative test in documenting the diagnosis of carcinoid disease.
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PMID:The pentagastrin test in the diagnosis of the carcinoid syndrome. Blockade of gastrointestinal symptoms by ketanserin. 257 77

A patient with the midgut carcinoid syndrome with severe diarrhoea and proven hypersecretion of serotonin (5-HT) was treated with low doses of verapamil perorally. During treatment the patient was completely relieved of diarrhoea but discrete facial flushing persisted during treatment. When treatment was cessated, diarrhoeas recurred. This patient underwent pentagastrin (PG) provocation repeatedly; during untreated conditions injection of PG released 5-HT, detectable in peripheral venous blood. Such release was abolished during verapamil treatment, but recurred after withdrawal of the drug. Surgical biopsies from this tumour were studied in two experimental models: cell suspensions and heterotransplants grown in the anterior eye-chamber of immunosuppressed rats. Release of 5-HT from the cell suspensions was elicited in a dose-dependent manner after stimulation with isoprenaline (IP) suggesting activation of beta-adrenoceptors on the tumour cells. Such release was reduced after pretreatment with verapamil indicating a calcium dependent mechanism. Intraocular tumour transplants also responded with release of 5-HT into the chamber fluid after conjunctival application of IP. However, pretreatment of the rats with verapamil significantly reduced the IP-stimulated release of 5-HT.
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PMID:Verapamil and diarrhoea in the carcinoid syndrome--clinical and experimental observations on serotonin release. 374 62

The intestinal carcinoid tumors of 26 patients were stained for the presence of serotonin, gastrin, somatostatin, motilin, secretin, glucagon, pancreatic polypeptide, ACTH, and neurotensin. Argentaffin and argyrophil stains were also performed in all cases. Thirty-five separate tumors (counting metastases and multiple primaries) from the 26 patients were studied. Serotonin was present in 30 of the 35 tumors. Nineteen tumors contained serotonin only. Fourteen tumors contained multiple neuroendocrine products. One tumor contained gastrin only. One tumor did not stain immunohistochemically, but was argyrophilic. Metastatic deposits were studied in nine patients. Some metastases produced the identical neuroendocrine products as the primary tumor, whereas others produced either additional or fewer hormones than the primary tumor. Moreover, different metastases from the same primary tumor were observed to produce different hormones. Argyrophilic cells were present in all cases and were much more numerous than cells staining by immunohistochemistry. Argyrophilic cells probably contain monoamines and polypeptide hormones in addition to those studied in this series. The argyrophil stain was the best general stain in this study for the demonstration of neuroendocrine cells. Argentaffin staining was negative in ten cases that were serotonin positive and two argentaffin positive cases were serotonin negative. The carcinoid syndrome, as clinically defined by the presence of flushing and diarrhea, was noted in five patients, all of whom had serotonin-containing small bowel carcinoids. Endocrine-related symptoms were not clinically appreciated in the remaining patients.
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PMID:The neuroendocrine products of intestinal carcinoids. An immunoperoxidase study of 35 carcinoid tumors stained for serotonin and eight polypeptide hormones. 618 28

The carcinoid syndrome is a rare clinical entity mainly characterized by flushing and diarrhoea. It is due to different biological mediators produced by tumours that arise from enterochromaffin cells. Such tumours are typically located in the ileum, have a long course and become symptomatic only in the presence of overt liver metastases. Among the involved mediators, the role of serotonin (5-hydroxytryptamine, 5-HT) has been ascertained in the pathogenesis of diarrhoea, while it remains controversial in that of flushing. Ketanserin is a 5HT-2 antagonist with no mixed receptor agonist-antagonist activity. We report the case of a severely distressing carcinoid syndrome fully dominated by ketanserin. The patient was a 75-year-old man, who came to our attention because of marked weight loss, impossibility to feed and almost continuous diarrhoea due to liver colonization of a mid ileum carcinoid tumour, previously resected at the age of 65. Sustained facial and trunk flushing also presented several times daily. Ketanserin, 20 mg twice a day orally, was administered and then increased up to 40 mg daily with no side effects and progressive complete control of both diarrhoea and flushing. It is suggested that ketanserin, due to its availability and tolerability, should first be considered for palliative relief of carcinoid syndrome. The literature on this subject is extensively reviewed.
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PMID:[Symptomatic relief of carcinoid syndrome by ketanserin. A case]. 763 30

Carcinoid tumors stimulate the release of specific hormones that lead to flushing, diarrhea, and bronchospasm. Serotonin is the most significant of these substances. Recently, a somatostatin analogue as well as the longer acting octreotide have been used to inhibit tumor secretions and reduce their untoward actions. This is a case report in which somatostatin was used perioperatively for removal of carcinoid tumors with an uneventful course.
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PMID:Carcinoid syndrome. 790 89

Several findings suggest that serotonin dysfunction may play at least a partial role in the etiology of social phobia. The cortisol response to fenfluramine, a serotonin agonist, is enhanced in patients with social phobia. Serotonin may be a common denominator between the blushing commonly seen in social phobics and the cutaneous flushing occurring in patients with carcinoid syndrome, although this is unlikely. Drugs that have demonstrated effectiveness in social phobia include the serotonin selective reuptake inhibitors (SSRIs), clonazepam (a benzodiazepine that potentiates serotonin function and synthesis), monoamine oxidase inhibitors (MAOIs) (which block the oxidative deamination of serotonin), and beta-adrenoceptor blockers (which control the synthesis of melatonin from serotonin). A variety of beta-blockers, some acting centrally and some peripherally, have been effective in the treatment of performance anxiety, a specific form of social phobia.
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PMID:Social phobia: everyone's disorder? 864 95

No statistical evaluation of patients with carcinoid syndrome in a reliable number of cases has been available in the past 35 years. To update our knowledge about the syndrome, we have evaluated from various clinicopathologic viewpoints a large series of patients with the syndrome reported up to date. The data of 748 patients with the syndrome were collected from 8876 carcinoid patients reported in the literature and analyzed by the Gut-Pancreatic Endocrinoma Analyzing System (the Niigata Registry). The results are summarized as follows. 1) The patients with the syndrome had a tendency to be older than those without it. 2) The incidence of the syndrome was 8.4% of 8876 carcinoid patients. 3) Serotonin activities were extremely high in patients with the syndrome as compared to those without it (91.7% versus 26.6%). 4) The rate of metastases was higher in patients with the syndrome than in those without it (84.8% versus 29.2%), and higher in the liver than in lymph nodes among patients with the syndrome (73.4% versus 37.4%). 5) Flushing and carcinoid heart as most specific clinical manifestations of the syndrome were recorded at 78.3% and 17.4%, respectively. 6) The 5-year survival rate after resection of primary lesions was 76.0% of 304 patients with the syndrome, lower in patients with digestive carcinoids than in those with extradigestive lesions (67.2% versus 88.7%). It is expected that the results obtained in the present evaluation on patients with carcinoid syndrome will provide investigators active in this specialized field with useful and extensive information for their future activities.
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PMID:Carcinoid syndrome: a statistical evaluation of 748 reported cases. 1046 98


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