Intestinal contribution to the presystemic elimination of β-phenethylamine in the rat

Abstract

Abstract The metabolism of β-phenethylamine (PEA) has been investigated in intestinal, liver and lung homogenates from the rat. Metabolic activity was ranked liver << lung << duodenum < jejunum < ileum < colon. Absorption and metabolism of PEA was also studied using in-situ intestinal loops from rats. Absorption of PEA appeared to be a passively mediated process with metabolism occuring in the jejunum, ileum and colon. When isolated loops of jejunum were used, phenylacetic acid was the only metabolite formed. Presystemic elimination of PEA in anaesthetized rats, was largely attributable to the intestine and lung with a relatively small hepatic contribution.