Sources of Urinary Histamine in the Rat

Abstract

Aminoguanidine, a diamine oxidase inhibitor, largely prevents histamine metabolism in rats. To test the feasibility of using urinary histamine levels as an indication of histamine released from bound condition in mammalian tissues, various bacterial and mammalian sources of urinary histamine were investigated. Histamine of intestinal bacterial origin is highly variable in amount and can reach enormous levels. Its formation can be almost completely suppressed by feeding antibacterial substances. Recommendations are made for the use of urinary histamine assays in testing histamine release.