RESIDUAL CATECHOLAMINES IN EXTRINSICALLY DENERVATED GUINEA‐PIG ILEUM

Abstract

1. Concentrations of noradrenaline, adrenaline and dopamine were measured in the submucosa and myenteric plexus of innervated and extrinsically denervated guinea‐pig ileum using a sensitive radioisotope enzymatic assay for catecholamines. 2. Subcellular fractionation studies indicated that the microsomal fraction obtained from both layers of the normal ileum was greatly enriched with noradrenaline compared to the total homogenate. Low levels of adrenaline and dopamine were also detected in both layers of the ileum. 3. After extrinsic denervation or pretreatment with reserpine, noradrenaline was reduced to less than 3% and could no longer be visualized histochemically. Small proportions of th..