Influence of decontamination of the digestive tract on the urinary excretion of histamine and some of its metabolites

Urinary excretions of histamine, N^t-methylhistamine and N^t-methylimidazoleacetic acid have been determined for 8 healthy volunteers during 14 consecutive days. Selective decontamination of the digestive tract was performed from day 3 to day 6, followed by total decontamination from day 7 to day 10. Urinary excretions of N^t-methylhistamine and N^t-methylimidazoleacetic acid decreased to a small though significant degree (about 15–20%) after total decontamination, suggesting a histamine production by anaerobic bacteria. Cadaverine decreased for about 70% under both selective and total decontamination, suggesting that this amine in human urine mainly originates from aerobic bacteria in the intestinal tract.To whom correspondence should be addressed.     

Studies on the excretion of [14C]histamine and its metabolites by the rabbit kidney

1. After intravenous administration of [(14)C]histamine in rabbits, the urinary excretion of [(14)C]histamine and [(14)C]histamine metabolites was examined over a period of 4 hr.2. It was found that [(14)C]histamine was excreted in the unchanged form only in small amounts (6-7%), while 54-71% was eliminated in the form of its metabolites.3. Under normal conditions, the percentage excretion of metabolites, but not of histamine, showed a dose dependence. With the higher [(14)C]histamine dose, a significantly smaller proportion of the dose given was excreted as metabolites than with the lower dose. The proportion of unchanged [(14)C]histamine excreted remained constant.4. Pre-treatment with histamine infusions, or with mepyramine maleate, caused an increase in the excretion of [(14)C]histamine metabolites while the excretion of [(14)C]histamine remained unchanged.5. Pre-treatment with a diuretic, a combination of mersalyl and theophylline, did not influence the excretion of [(14)C]histamine nor of its metabolites.     

Effects of isoprenaline and terbutaline on urinary excretion of histamine and its two main metabolites in systemic mastocytosis

Both short-term and long-term effects of the -sympathomimetic drugs isoprenaline and terbutaline on the urinary excretion of histamine and its two main metabolites were evaluated in patients with systemic mastocytosis.In a short-term study isoprenaline and terbutaline were given intravenously during five hours to three and two patients, respectively. Compared with placebo infusion N^t-methyl-histamine excretion fell during terbutaline administration, whereas during isoprenaline no changes were observed.In a long-term study three patients received a treatment with orally administered terbutaline for 24 days. In one patient a slight reduction of the excretion of the histamine metabolites was found. In another patient the excretion of histamine and its metabolites, decreased especially during the eight days observation period after the end of the treatment. In this study we saw occasionally large and rapid changes occurring simultaneously in all three urinary parameters of histamine release.In conclusion, terbutaline can reduce histamine release in systemic mastocytosis. However, because of the small symptomatic and biochemical effects found in our patients, the clinical significance of -sympathomimetic drug treatment in this disease has yet to be established.     

Urinary excretion of metabolites of catecholamines in normal individuals and hypertensive patients

The 24-hour urinary output of 3-methoxy-4-hydroxy mandelic acid (V.M.A.) has been determined in 20 normal adults, 150 hypertensive patients, and four cases of phaeochromocytoma. In this last group estimations of urinary catecholamines and total urinary methylated amines were also performed and the overall results have been compared with the urinary excretory pattern of catecholamines and their metabolites following the injection of radioactive adrenaline and noradrenaline.     

Urinary dopamine excretion in healthy volunteers: effect of sodium diet and acute water load

The present study was designed to investigate, in human subjects, urinary dopamine excretion under different conditions of sodium and water homeostasis. In a cross-over trial, ten healthy volunteers were subjected to low-salt (LS; dietary salt restriction, sodium chloride (NaCl) intake <5 g per day), normal-salt (NS; normal food ad libitum), and high-salt (HS; normal food plus NaCl 100 mg/kg per day) regimens for 8 days in a randomized order. On day 7, urine was collected for 24 h. The variations in urinary sodium excretion reflected the dietary salt intake (LS: 16.3+/-4.7; NS: 144.1+/-18.2; HS: 221.9+/-12.9 mmol 24 h(-1) 1.73 m(-2)), but were not accompanied by significant changes in urinary dopamine excretion. On day 8, clearance studies showed that an acute oral water load of 1500 ml did not alter glomerular filtration rate or renal plasma flow but significantly increased urinary flow rate without affecting dopamine excretion. Assuming that excreted dopamine is not metabolized or reabsorbed during the tubular passage, both the unchanged urinary dopamine output in spite of 14-fold variations in sodium excretion and its independence of an acute water load argue against the hypothesis that dopamine in the tubular lumen acts as a natriuretic and/or diuretic factor in humans.     

Urinary excretion of electrolytes during prolonged physical activity in normal man

Summary Nine normal young male students were studied during 2 days of relative rest, during 2 days of physical training and again during the succeeding 2 days of relative rest.Twenty-four hour urine collections showed that sodium and potassium excretion were lower during the exercise days, while urinary aldosterone excretion was increased. No differences in the 24-h urinary excretion of creatinine, calcium, and magnesium were found between the resting and exercise days.Hemoglobin concentration, hematocrit and red cell counts were decreased at 14 h and 42 h after exercise; these findings together with the increased serum bilirubin concentration could result from hemolysis.Plasma renin activity, angiotensin II and aldosterone concentration were increased 14 h after exercise but returned to baseline 42 h after exercise.Our data shows that one should take into account previous exercise when interpreting results of certain of these tests.     

Correlation between urinary levels of histamine metabolites in 24-hour urine and morning urine samples of man: Influence of histamine-rich food

In this study, we have determined and correlated the excretion of the 2 most important histamine metabolites, N-methylhistamine and N-methylimidazoleacetic acid, in 24-hour urine and morning urine samples of 14 normal healthy persons. We found no significant difference between morning urine and 24-hour urine samples, provided that the subjects were on a histamine-poor diet for at least 24 hours. We also studied the influence of the consumption of histamine-rich foodstuffs on the reliability of these parameters. The morning urinary N-methylhistamine excretion is less affected by histamine-rich foodstuffs and therefore proposed to be the most reliable parameter for endogeneous histamine release.     

Urinary excretion kinetics of hydroxyethyl starch 350/0.60 in normovolaemic man.

Rates of urinary excretion concomitant with the molecular size distribution of filtered polymer fragments were determined in five normovolaemic men dosed with 30 g/m2 BSA of a species of HES (HES 350/0.60) possessing a M-W of 350 000 combined with an MS of 0.60. Approximately 13% of the total injected dose of HES 350/0.60 was excreted in urine 1 hr after dosing, and 45% by 72 hours. Gel filtration of Sepharose CL-4B revealed that aliquots of urine collected 1 hour after injection contained polymer fragments of HES 350/0.60 with values of Kav ranging between 0.88 and 0.84, and possessed a Stokes radius (r = 32A) similar to that of Dextran 20 (M-W 22 700). Polymer fragments of HES 350/0.60 excreted 6 to 48 hours after dosing, however, possessed a Kav ranging between 0.78 and 0.73 with a Stokes radius (r = 45A) similar to that of Dextran 40 (M-W 41 000). All filtered polymer fragments were less polydisperse relative to both the injection solution (Kav 0.60) and residual material recovered from blood immediately after injection (Kav 0.72). These data support the hypothesis that the excretion of HES 350/0.60 occurs in two distinct phases: a rapid phase of elimination dependent on the M-n of the injected solution, and a slower phase dependent on the MS (degree of resistance to alpha-amylase attack). This study, in conjunction with our previous investigation of the changes in circulating HES 350/0.60, define the basic differences between clearance and excretion of the dextrans and of the rapidly degraded species of HES. These data are relevant to the utilisation of HES 350/0.60 during centrifugal leucapheresis.     

The relationship between body size and the urinary excretion of the main histamine metabolite tele-methylimidazoleacetic acid in man

Inflammation Research -     

Urinary excretion of 19-norandrosterone of endogenous origin in man: quantitative analysis by gas chromatography-mass spectrometry

A GC-MS method, using deuterium-labelled 19-noretiocholanolone as internal standard and following an extensive LC purification prior to selected ion monitoring of the bis(trimethylsilyl) ethers at ion masses m/z 405, 419, 420 and 421, allowed the quantitation of subnanogram amounts of 19-norandrosterone present in 10-ml urine samples at m/z 405. Thirty healthy men, free of anabolic androgen supply, delivered 24-h urine collections in 4 timed fractions. Accuracy was proven by the equation, relating added (0.05-1 ng/ml) to measured analyte, which had a slope not significantly different from 1. Precision (RSD) was 4% at a concentration of 0.4 ng/ml, and 14% at 0.04 ng/ml. Analytical recovery was 82%. The limit of quantitation was 0.02 ng/ml. The excretion ranges were 0.03-0.25 microg/24 h or 0.01-0.32 ng/ml in nonfractionated 24-h urine. Taking into account inter-individual variability and log-normal distribution, a threshold of 19-norandrosterone endogenous concentration of 2 ng/ml, calculated as the geometric mean plus 4 SD, was established. This value corresponds to the decision limit advised by sport authorities for declaring positive (anabolic) doping with nandrolone.