Articles: histamine.
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Journal of biochemistry · Dec 1984
Histamine metabolism in patients with histidinemia: determination of urinary levels of histamine, N tau-methylhistamine, imidazole acetic acid, and its conjugate(s).
Histamine metabolism in histidinemic patients was studied by measuring the urinary levels of histamine and its metabolites. The urinary excretions of histamine, N tau-methylhistamine, imidazole acetic acid, and its conjugate(s) were higher in patients with histidinemia than in controls, and these levels of excretion were correlated with the plasma histidine level. ⋯ The urinary excretion of 3-methylhistidine showed a close correlation with the urinary histidine excretion. Thus, it was concluded that histamine metabolism is higher in histidinemic patients than in normal controls.
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Scand. J. Gastroenterol. Suppl. · Jan 1984
Enhancement of duodenal and jejunal ulceration by histamine-induced gastric hypersecretion in dogs with diversion of duodenal contents.
In a previous investigation deviation of duodenal contents protected rats significantly from the development of peptic ulceration under maximal acid secretion. We have now assessed the effect of diversion of duodenal contents in dogs submitted to the same operative procedure under histamine-induced hypersecretion. Six mongrel dogs underwent the following procedure: A two cm duodenal segment was left adjacent to the intact pylorus, proximal jejunum anastomosed to this segment and a Roux-en-Y duodeno-jejunostomy performed. ⋯ It was concluded that the diversion of duodenal contents enhanced ulcer formation in dogs and that the model mimicked a Zollinger-Ellison Syndrome. Ulceration occurred in transitional or jejunal type of duodenal mucosa. No gastric lesions were found and this suggests that the diversionary procedure was an effective means of preventing bile from reaching the gastric mucosa.
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Comparative Study
Effects of serotonin and histamine on proximal and distal coronary vasculature in dogs: comparison with alpha-adrenergic stimulation.
The effect of several vasoactive agents on epicardial conductance arteries and distal resistance arteries was studied in intact dogs using a special catheter system to infuse vasoactive mediators directly into the left anterior descending coronary artery of intact dogs. Serotonin produced significant epicardial vasoconstriction (42% cross-sectional area reduction, p less than 0.01), whereas histamine had no effect on proximal coronary arteries. ⋯ These results show that vasoactive mediators can have different actions on coronary resistance and conductance vessels. Serotonin is a potent vasoconstrictor of epicardial coronary arteries but does not produce significant constriction of coronary resistance vessels.
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Br J Clin Pharmacol · Feb 1980
Elevated blood histamine levels and mast cell degranulation in solar urticaria.
1 Ultraviolet radiation (UVR)-induced wealing was studied in four patients with solar urticaria, whose measured action spectra were within the range 300 to 700 nm. 2 Elevated histamine levels were found in blood draining wealed skin in all four patients. 3 Histological and electron microscopial studies of the irradiated skin showed evidence of mast cell degranulation. 4 These findings demonstrate an association between histamine release from mast cells and wealing in solar urticaria, and should encourage evaluation of drugs which suppress histamine release in this disorder.