Age Changes in the Urinary Histamine Excretion of Rats

Abstract

In 577 determinations on 135 rats the age change in urinary excretion of histamine was investigated. After administering water, histamine concentration in 12-hour urine was estimated on the isolated atropinized guinea pig ileum. The results show that histamine concentration in the urine during growth (up to 44 wk.) and the amount of histamine excreted daily per gram body weight decreases with increasing age. Against this, the daily total histamine content of urine does not substantially change during the same period. At older ages (50–120 wk.) both the histamine concentration in urine and the total daily excretion drop substantially, the decrease in 2-year-old rats being almost to 1% of the values in young rats.

Comparison of the Effects of Various Agents on Histamine Release and Mast Cells in the Rat, <i>in vivo</i> and <i>in vitro</i>

“…After intravenous injection of one of the agents listed below, the symptoms and body temperature were recorded and animals surviving for two hours were then sacrificed. For the assessment of histamine content, 5-6 equal pieces of mesenteries were obtained from each of the treated animals and from controls, by fixing them to metal rings of equal size (3); histamine was extracted from these tissues with 10% trichloroacetic acid and, after the pH value had been adjusted to 7.4-7.6, assayed on the isolated guinea-pig ileum in comparison with a standard solution of histamine dihydrochloride (6,7). For evaluation of the mast-cell alterations, the animals were perfused through the carotid artery with a fixative of 50% aqueous ethanol containing 10% formaldehyde and 5% acetic acid (8), and the mesenteries stained with toluidinc blue (1 %), and mounted.…”

Tissue Mast Cells in Anaphylactic Shock and Anaphylactoid Reactions

“…With some animals we collected the 12-hour urine during the shock tests and measured the histamine content (for the method, see 40).…”