Excretion of 3 H-Histamine in Urine of Rats with Portacaval Shunts 1

Abstract

Summary

It has been reported previously by two groups of investigators that portacaval shunt in rats is followed by the increased enzymatic synthesis of histamine in the gastrointestinal tract and by the elevated excretion of histamine in urine. The purpose of our experiment was to determine whether side-to-side portacaval shunt affects the urinary excretion of radioactive histamine following the injection of radioactive histidine. Female rats with shunts and sham-operated animals received ³H-L-histidine intravenously. Urine was collected from these animals for four 24-hr periods and analyzed for ³H-L-histamine. The expected elevation of urinary histamine in shunted animals was not found. The excretion of ³H-histamine was lower in animals with portacaval shunts than in controls. Shunted animals excreted more urine than sham-operated rats. The results of this preliminary experiment do not support the hypothesis of an increased synthesis and excretion of histamine in animals with portacaval bypass.