Metabolism of histamine during pregnancy in the rat

Abstract

In order to clarify histamine metabolism during the period of pregnancy in which this amine attains the highest levels, pregnant and non-pregnant rats were submitted to four different treatments: 14C-histamine; 14C-histamine + histamine dihydrochloride; 14C-histamine + aminoguanidine; 14C-histidine.Paper chromatography and autoradiographic techniques were used to separate and to detect 14C-histamine metabolites.Total radioactivity excreted and percentages of histamine metabolites were calculated by liquid scintillation.Our results support two principal hypotheses: 1) Oxidation is the main catabolic pathway for histamine degradation in pregnant and non-pregnant rats.2) Pregnant rats, in opposition to non-pregnant, show an increased capacity to metabolize histamine by oxidative deamination.