Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20366 (substance P)
 21,176 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of synthetic cyclic somatostatin 14 were studied in two patients with the carcinoid syndrome. The 3-hour intravenous administration of somatostatin (250 micrograms X h-1), a) resulted in the disappearance of flushing in the first patient but was without any clinical effect in the second subject who remained chronically colored; b) lowered plasma levels of motilin, prostaglandins (E1, E2 and F2 alpha) and to a lesser extent of catecholamines in both patients whereas the serotonin level was not altered; c) was followed by a rebound effect with recurrence of severe flushing in the first patient and was associated with a dramatic increase of prostaglandin, substance P and catecholamine levels in both patients. The inhibitory effect of somatostatin and the occurrence of a rebound effect at the end of infusion were confirmed by infusing somatostatin (6 mg per day) during 48 h in the first patients. These results: a) show that somatostatin is an effective drug in carcinoid syndrome with severe flushing; b) confirm that several mediators are affected in carcinoid syndrome. However it could not be excluded that increased circulating levels of prostaglandins, substance P and catecholamines may represent unrelated secondary events; c) suggest that somatostatin primarily inhibits the release rather than the synthesis of tumor products. Owing to the severity of the rebound effect, treatment of the carcinoid syndrome with somatostatin must be undertaken with precaution until specific long-acting analogs are available.
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PMID:[Effects of the administration of somatostatin 14 in the carcinoid syndrome. Clinical and biological study of 2 cases]. 614 Nov 19

Twenty-five endocrine tumors of the rectum (rectal carcinoids) were examined immunohistochemically for various pancreatic and gut neurohormonal polypeptides. Twenty-one of the tumors were found to contain cells displaying pancreatic polypeptide (PP), glucagon, somatostatin, insulin, substance P, enkephalin or beta-endorphin immunoreactivity. At least 11 of the tumors contained more than one peptide hormone. In some of the tumors PP cells made up the major cell population, in others the glucagon cells constituted the majority. Only four of the tumors contained 5-hydroxytryptamine. Rectal endocrine tumors seem unique among gut endocrine tumors in that they may store immunoreactive enkephalin, beta-endorphin and even insulin. None of the patients displayed the carcinoid syndrome; symptoms were usually vague and uncharacteristic. In many cases the tumor was found at routine examination.
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PMID:Immunohistochemical evidence of peptide hormones in endocrine tumors of the rectum. 617 Apr 21

Serotonin and substance P circulate in high concentrations in patients with the carcinoid syndrome. These studies were performed to evaluate the effects of intravenous infusions of serotonin and substance P to reproduce carcinoid levels of these agents on central hemodynamics, regional blood flow (using the radioactive microsphere technique), and endogenous hormone release. Serotonin did not affect mean arterial pressure but it significantly increased cardiac output, decreased systematic vascular resistance, and redistributed regional blood flow, increasing blood flow to the heart, adrenals, fundus, and antrum. Substance P significantly decreased mean arterial pressure and systemic vascular resistance, increased cardiac output, and increased blood flow to adrenal, fundus, antrum, liver, and all muscular layers of the stomach and small bowel. Neither serotonin nor substance P affected skin blood flow, nor altered circulating levels of glucose, insulin, or gastrin. Although both of these agents seem to participate in the pathogenesis of the carcinoid syndrome, our studies suggest that it is not possible to ascribe all the hemodynamic abnormalities to either.
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PMID:The effect of carcinoid levels of serotonin and substance P on hemodynamics. 619 79

A 55-year-old woman with an ovarian carcinoid presented with intermittent facial and cervical flushing for 10 years, watery diarrhea for 4 years, and abdominal pain without hepatomegaly. Markedly elevated systemic venous and arterial serotonin levels (830 ng/ml; nl = 50-200 ng/ml) were found. The highest serotonin levels were observed in the superior vena caval system, but serotonin as a marker for tumor localization was inaccurate and led to an unproductive neck exploration. The histological pattern of this tumor contained purely insular elements. No hepatic or nodal metastases were identified and the lesion was unilateral. Substance P levels were elevated in the venous drainage of the left ovary and in retrospect correctly localized the ovarian tumor. This peptide may prove to be another carcinoid tumor marker in addition to serotonin and 5-hydroxyindoleacetic acid. Substance P may also be an important mediator of symptoms in patients with carcinoid syndrome.
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PMID:Substance P in the localization of a carcinoid tumor. 620 86

The cases of three patients with primary carcinoid tumor of the testis were reported. The patients were 41, 44, and 83 years of age. At initial examination, all three had testicular masses with or without associated pain, and none had the carcinoid syndrome. The tumors measured 4.3 cm, 3.0 cm, and 6.5 cm in dimension. All three tumors manifested classic histologic features of carcinoid tumors. The neoplastic cells exhibited argyrophilia, and all were immunoreactive to chromogranin, serotonin, neuron-specific enolase, and cytokeratin. Two tumors had positive test results for gastrin and one had positive test results for substance P and vasoactive intestinal polypeptide. No tumors reacted with somatostatin, insulin, pancreatic polypeptide, or placental alkaline phosphatase. Intracytoplasmic, membrane-bound, round-to-elliptical pleomorphic granules were identified by ultrastructural analysis in all cases. DNA flow cytometric analysis revealed a low degree (near-diploid) DNA aneuploidy in all cases, with a DNA index of 1.15 in two tumors and 1.3 in the third tumor. The three patients are alive and well 11 years, 7 years, and 6 months, respectively, after diagnosis. A total of 57 cases of this entity, including the 3 reported here, have been reported. Of these, 43 were pure carcinoid, and 14 were associated with teratoma; 6 (11.6%) patients developed metastases. Tumor size and the presence of carcinoid syndrome have been found to correlate with metastatic potential. Neither tumor necrosis nor local tumor invasion (into vessels, tunica albuginea, etc.) correlated with adverse prognosis. Carcinoid tumor of the testis is a rare indolent neoplasm with potential for distant metastases.
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PMID:Primary carcinoid tumor of testis. Immunohistochemical, ultrastructural, and DNA flow cytometric study of three cases with a review of the literature. 768 60

A case of carcinoid tumour of the small intestine has been reported, which caused hormone producing multiple hepatic metastases. The 45 year old man had flush syndrome several times a day, that was caused by a carcinoid tumour originated from the jejunum. After the operation of the primary tumour he was treated by Sandostatin (Sandoz, Basel), which significantly reduced the symptoms and slowed down the progression. The neural elements containing substance P, neuropeptide Y, vasoactive intestinal polypeptide, serotonin, dopamine-beta-hydroxylase and somatostatin, which are thought to cause the symptoms, were investigated in the small intestine and the liver metastasis by an immunocytochemical method. It seems to be an interesting observation, that a large number of neuropeptide Y immunoreactive nerve fibers and some substance P and vasoactive intestinal polypeptide immunoreactive nerve processes and cell bodies were observed however, no trace of somatostatin and serotonin immunoreactive nerve elements could be detected in the hepatic metastasis. That can be a novel addition to the possible aetiology of the carcinoid syndrome and to the way how the somatostatin treatment acts.
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PMID:[Treatment of carcinoid tumor with a long-acting somatostatin analog]. 843 17

Tachykinins are a family of peptides that may be present in and secreted from carcinoid tumours of mid-gut origin. They are likely to play a role in the pathogenesis of, e.g. the flush, dyspnoea and valvular heart disease seen in the carcinoid syndrome. Since tachykinins are secreted from the tumour into the circulation in bursts, coinciding with flushing attacks, and have short half-lives, we anticipated that analysis of 24-h urine excretion of immunoreactive tachykinin metabolites might prove to be a more sensitive and stable parameter for monitoring than tachykinin-like immunoreactivity in plasma. The study included 48 patients hospitalized for treatment of advanced carcinoid tumours and 32 healthy controls. The urine excretion of tachykinin-like immunoreactive metabolites in the carcinoid patients (median 27.5 pmol 24 h-1, interquartile range (IQR) 8.5-51.0 pmol 24 h-1) was significantly (p<0.001) higher than that in the 32 healthy subjects (median 3.0 pmol 24 h-1, IQR 0.9-4.20 pmol 24 h-1). Of the patients, 38 (79%) had elevated 24-h urine excretion of tachykinin-like immunoreactive metabolites while 31 (64%) had elevated plasma concentrations of tachykinin-like immunoreactive metabolites. Of the patients, 27 (56%) had elevated concentrations of tachykinin-like immunoreactive metabolites both in plasma and urine, 12 (25%) had elevated concentrations only in urine excretion, 3 (6%) had elevated concentrations of only plasma tachykinin-like immunoreactive metabolites and 7 (14%) had elevation of neither plasma nor urine concentrations. Analysis by means of different column chromatographic techniques indicated that the immunoreactive material was heterogeneous, with some components co-eluting with oxidized neurokinin A (NKA) and neuropeptide K (NPK). The urine tachykinin-like immunoreactivity correlates well with that of plasma, but is a slightly more sensitive indicator of elevated tachykinin-like immunoreactivity, probably since levels of urine tachykinin-like immunoreactive metabolites reflect the overall amount of the latter secreted into the circulation during 24 h.
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PMID:Immunoreactive tachykinins in 24-h collections of urine from patients with carcinoid tumours: characterization and correlation with plasma concentrations. 890 38

A method is described for the determination of bradykinin, neuropeptide K (NPK), and substance P in patients with atypical carcinoid syndrome. The developed method uses a combination of conventional and solid-phase extraction as well as high-performance liquid chromatographic techniques. A narrow-bore C18 column with ultraviolet detection is used (200 nm). The technique recovers bradykinin at a level of 98%, NPK at 96%, and substance P at 98% (when pure standards are dissolved) at concentration levels relevant to the atypical carcinoid syndrome. In biological samples, the recovery rate of bradykinin, NPK, and substance P drops to 88, 86, and 88% respectively. The overall analysis time is 150 min from receipt of samples. This method proves to be a valuable tool in the identification of neuropeptides and thus the diagnosis of atypical carcinoid syndrome, especially in puzzling cases with nonspecific symptoms.
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PMID:High-performance liquid chromatographic analysis with diode-array detection of bradykinin, neuropeptide K, and substance P in human plasma. 963 18

5-HT3-receptor antagonists are potent and highly selective competitive inhibitors of the 5-HT3-receptor with negligible affinity for other receptors. They are rapidly absorbed and penetrate the blood-brain barrier easily. 5-HT3-receptor antagonists are metabolized by diverse subtypes of the cytochrome P450-system, metabolites are excreted mainly in urine. Half-lifes in healthy subjects vary from 3-4 hours (ondansetron, granisetron) to 7-10 hours (tropisetron, hydrodolasetron). 5-HT3-receptor antagonists do not modify any aspect of normal behaviour in animals or induce remarkable changes of physiological functions in healthy subjects. They are well tolerated over wide dose ranges, most common side effects in clinical use are headache and obstipation. Clinical efficacy was first established in chemotherapy-induced emesis. In this indication, 5-HT3-receptor antagonists set a new standard regarding efficacy and tolerability. Further established indications are radiotherapy-induced and post-operative emesis. Antiemetic efficacy results from a simultaneous action at peripheral and central 5-HT3-receptors. Other peripheral actions include reduction of secretion and diarrhea caused by increased intestinal serotonin content (e.g. in carcinoid syndrome), a limited antiarrhythmic activity and a reduction of experimentally induced pain. CNS effects comprise anxiolysis, attenuation of age-associated memory impairment, reduction of alcohol consumption in moderate alcohol abuse and an antipsychotic effect in patients with parkinson psychosis. In migraine, 5-HT3-receptor antagonists show moderate efficacy, as well. Repeatedly demonstrated efficacy of 5-HT3-receptor antagonists in patients suffering from fibromyalgia raises the question for the mechanism of action involved. Ligand binding at the 5-HT3-receptor causes manifold effects on other neurotransmitter and neuropeptide systems. In particular, 5-HT3-receptor antagonists diminish serotonin-induced release of substance P from C-fibers and prevent unmasking of NK2-receptors in the presence of serotonin. These observations possibly provide an approach for the causal explanation of favourable treatment results with 5-HT3-receptor antagonists in fibromyalgia.
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PMID:Preclinical and clinical pharmacology of the 5-HT3 receptor antagonists. 1102 30

Nausea and vomiting are common distressing symptoms with multiple etiologies. Serotonin and substance P can induce nausea and vomiting by binding to specific receptors (5-hydroxytryptamine3 [5HT3] and neurokinin-1 [NK-1] receptors respectively). Carcinoid tumors, which originate from enterochromaffin cells of the neuroendocrine system, secrete several biologically active amines and peptides, including serotonin and substance P, that are responsible for the distant effects of this tumor. The authors present an 88-year-old lady with metastatic carcinoid tumor, with evidence of carcinoid syndrome. She had nausea and vomiting that became unresponsive to 5HT3 receptor antagonists and other antiemetics. As substance P is released from carcinoid tumors and has a role in the pathogenesis of emesis, the NK-1 receptor antagonist aprepitant was trialed. This provided complete and sustained improvement of the nausea and vomiting until her death 2 months later. This case demonstrates the potential role and rationale of NK-1 receptor antagonists in the management of resistant emesis in patients with carcinoid tumors. Clinical trials are needed to evaluate the efficacy and toxicity of these drugs in the management of emesis in patients with carcinoid syndrome.
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PMID:Aprepitant for the management of refractory emesis in a patient with a small bowel carcinoid tumor. 2483 5


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