Search results for "antagonist"
showing 10 items of 1660 documents
Mucosa-dependent muscarinic liberation of prostaglandins from rat isolated trachea.
1995
1. The present study examined whether cholinoceptor stimulation modulates the release of arachidonic acid-derived mediators from rat isolate tracheae. 2. Tracheae were preincubated with [3H]-arachidonic acid and the outflow of 3H-compounds was determined. Acetylcholine and the muscarinic agonist, carbachol but not nicotine, increased the rate of tritium outflow maximally by about 30%. The M3 receptor-preferring antagonist rho-fluoro-hexahydrosiladiphenidol was more effective than pirenzepine and methoctramine in antagonizing the effect of acetylcholine. 3. High performance liquid chromatography analysis (methanol gradient) of the released 3H-compounds showed that one peak, co-eluting with […
Histamine and spontaneously released mast cell granules affect the cell growth of human hepatocellular carcinoma cells
2007
The role of mast cells in tumor growth is still controversial. In this study we analyzed the effects of both histamine and pre-formed mediators spontaneously released by mast cells on the growth of two human hepatocellular carcinoma cell lines, HA22T/VGH and HuH-6, with different characteristics of differentiation, biological behavior and genetic defects. We showed that total mast cell releasate, exocytosed granules (granule remnants) and histamine reduced cell viability and proliferation in HuH-6 cells. In contrast, in HA22T/VGH cells granule remnants and histamine induced a weak but significant increase in cell growth. We showed that both cell lines expressed histamine receptors H(1) and …
A Review of the Cardiovascular and Anti-Atherogenic Effects of Ghrelin
2013
Ghrelin is a peptide hormone produced mainly in the stomach that has widespread tissue distribution and diverse hormonal, metabolic and cardiovascular activities. The circulating ghrelin concentration increases during fasting and decreases after food intake. Ghrelin secretion may thus be initiated by food intake and is possibly controlled by nutritional factors. Lean subjects have increased levels of circulating ghrelin compared with obese subjects. Recent reports show that low plasma ghrelin is associated with elevated fasting insulin levels, insulin resistance and type 2 diabetes mellitus. Factors involved in the regulation of ghrelin secretion have not yet been defined; however, it is as…
Special Considerations for Antihypertensive Agents in Dialysis Patients
2010
Hypertension is present in most patients with end-stage renal disease and likely contributes to the premature cardiovascular disease in dialysis patients. Previous practice guidelines have recommended that, in patients on chronic dialysis, blood pressure (BP) should be reduced below 130/80 mm Hg. This is based on opinions but not strong evidence, since no concrete information exists about which BP values should be the parameter to follow and which should be the target BP values. The majority of the antihypertensive agents can be used in this population, but the pharmacokinetics altered by the impaired kidney function and dialyzability influence the appropriate dosage as well as the time and…
Behandlung der ausgeprägten Pubertätsgynäkomastie mit Tamoxifen
1987
Based on the good results of another author 10 boys with marked pubertal gynecomastia were treated with the antioestrogen Tamoxifen (Nolvadex) at a dose of 20-40 mg/d orally for 2-12 months. In most cases the gynecomastia decreased totally, only two patients experienced palpable subareolar glandular tissue at the end of therapy. Side effects were not noted. During therapy levels of estradiol and testosteron increased, with a more pronounced elevation of estradiol. Basal values of LH and FSH remained nearly unchanged, but LH showed an increased response to LH-RH, which could be explained by the antioestrogenic effect of Tamoxifen at the hypothalamic level. The reduction of breast size in spi…
Differences in zinc status and the leptin axis in anorexic and recovered adolescents and young adults : a pilot study
2012
Food & nutrition research 56, 8 S. (2012). doi:10.3402/fnr.v56i0.10941
Anti-androgens for the treatment of hirsutism.
2002
Many alternatives exist for treating hirsutism. Based on an analysis of scientific literature and on the experiences of the author, the most common anti-androgen agents are discussed in this review. Androgen receptor blockers (cyproterone acetate, flutamide and spironolactone), 5 alpha-reductase inhibitors (finasteride) and androgen-suppressing agents (gonadotrophin-releasing hormone [GnRH] agonists, oestroprogestins, corticosteroids and insulin-sensitising agents) are evaluated and compared. The importance of diagnosis in choosing the most appropriate anti-androgen treatment is also discussed.
Pharmacological investigation into the effects of histamine and histamine analogues on guinea-pig and rat colon in vitro.
1986
The effects of histamine and specific histamine agonists has been examined on isolated longitudinal colon strips of guinea-pig and rat. Histamine and 2-pyridyl-ethylamine but not 4 methylhistamine produced a concentration-related contractile response in the guinea-pig colon. The H1-antagonist clemizole antagonized competitively the effect of histamine but the H2-antagonist ranitidine did not modify the dose-response curve to histamine in the guinea-pig colon. Atropine, hexamethonium, prazosin and propranolol failed to modify the contractile response to histamine. Tone induced with KCl in guinea-pig isolated colon was not modified by histamine agonists even in tissues pretreated with clemizo…
Identification of α2-adrenoceptors and non-adrenergic idazoxan binding sites in rabbit colon epithelial cells
1990
alpha 2-Adrenoceptors are possibly involved in the regulation of the hydroelectrolytic flux across the digestive mucosa. As no data are available concerning the existence of these receptors in colon epithelial cells, we aimed to investigate the existence of alpha 2-adrenoceptors in this tissue using tritiated antagonists. [3H]Yohimbine and [3H]rauwolscine were not usable to label colonic alpha 2-adrenoceptors because of their very high level of non-specific binding. In contrast, the methoxy derivative of idazoxan, [3H]RX821002, appeared a convenient radioligand for the purpose. [3H]RX821002 bound with high affinity (KD = 6.2 +/- 0.8 nM) to a single population of non-interacting sites (Bmax …